Cisco ASR 9000 Series Aggregation Services Router Routing Command Reference, Release 4.1
BGP Commands
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BGP Commands

Contents

BGP Commands

This chapter describes the commands used to configure and monitor Border Gateway Protocol (BGP) on Cisco ASR 9000 Series Aggregation Services Routers using Cisco IOS XR software. The commands in this module configure IP Version 4 (IPv4), IP Version 6 (IPv6), Virtual Private Network Version 4 (VPNv4) routing sessions.

For detailed information about BGP concepts, configuration tasks, and examples, see the Implementing BGP chapter in the Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide.


Note


Running the show bgp command immediately after configuring a large and complex route policy may result in timeout of the system database shown through an error message (SYSDB-SYSDB-6-TIMEOUT_EDM). It is recommended that the show command be run after the new route policy takes effect.


accept-own

To enable handling of self-originated VPN routes containing ACCEPT_OWN community attribute, use the accept-own command in neighbor VPNv4 or VPNv6 address family configuration mode. To disable this functionality, either use the no form of this command or use the command with inheritance-disable keyword.

accept-own [inheritance-disable]

no accept-own

Syntax Description

inheritance-disable

Disables handling of self-originated VPN routes containing ACCEPT_OWN community attribute and prevents inheritance of Accept Own from a parent configuration.

Command Default

Disabled

Command Modes

Neighbor address family VPNv4

Neighbor address family VPNv6

Command History

Release Modification

Release 4.1.1

This command was introduced.

Usage Guidelines

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to enable handling of accept-own community:

RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 10.2.3.4
RP/0/RSP0/CPU0:router(config-bgp-nbr)#address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)#accept-own

additional-paths install backup


Note


Effective with Release 4.0.0, the additional-paths install backup command was deprecated and replaced by the additional-paths selection command. See the additional-paths selection command for more information.


To install a backup path into the forwarding table and provide prefix independent convergence (PIC) in case of a PE-CE link failure, use the additional-paths install backup command in an appropriate address family configuration mode. To prevent installing the backup path, use the no form of this command. To disable prefix independent convergence, use the disable keyword.

additional-paths install backup [ disable ]

no additional-paths install backup

Syntax Description

disable

Disables installing backup path into the forwarding table.

Command Default

None

Command Modes

VRF IPv4 address family configuration

VRF IPv6 address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Release 4.0.0

This command was deprecated replaced by the additional-paths selection command.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable installing a backup path into the forwarding table in VPNv4 address family mode:

RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)#additional-paths install backup

Related Commands

Command

Description

retain local-label

Retains the local label until the network is converged.

additional-paths receive

To configure receive capability of multiple paths for a prefix to the capable peers, use the additional-paths receive command in address-family configuration mode. To disable receive capability, use the no form of this command. To disable add-path receive capability for all neighbors belonging to a particular VRF address-family, use the disable option.

additional-paths receive [disable]

no additional-paths receive

Syntax Description

disable

Disables advertising additional paths receive capability.
Note   

Use the disable keyword option to disable add-path receive capability for all neighbors belonging to a specified VRF address-family.

Syntax Description

This command has no keywords or arguments.

Command Default

None

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Use the additional-paths receive command to allow add-path receive capability to be negotiated for a specified address family. When the additional-paths receive command is configured, the receive capability is automatically enabled for all internal BGP neighbors for a specified address family. When this command is either not configured or explicitly disabled, none of the neighbors are allowed to negotiate receive capability for the address family.

After enabling the receive capability, the session needs to be reset for the configuration to take into effect.

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to enable additional paths receive capability under VPNv4 unicast address family:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:routerconfig)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# additional-paths receive

This example shows how to disable additional paths receive capability for all neighbors belonging to a particular VRF address-family (vrf1):
RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config-bgp)#vrf vrf1
RP/0/RSP0/CPU0:router(config-bgp-vrf)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-vrf-af)#additional-paths receive disable

Related Commands

Command

Description

additional-paths send

Configures send capability of multiple paths for a prefix to the capable peers.  

capability additional-paths send

Advertises capability of sending additional paths to the peer.  

capability additional-paths receive

Advertises additional paths receive capability.  

additional-paths selection

To configure additional paths selection mode for a prefix, use the additional-paths selection command in address-family configuration mode. To disable the additional-paths selection mode for a prefix, use the no form of this command. To disable the additional-paths selection mode for a particular VRF address-family, use the disable option.

additional-paths selection { route-policy route-policy-name | disable }

no additional-paths selection route-policy route-policy-name

Syntax Description

route-policy route-policy-name

Specifies the name of a route policy used for additional paths selection.

disable

Disables add-path selection for a particular VRF address-family.

Command Default

None

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

To configure additional paths selection mode for some or all prefixes, use the additional-paths selection command by specifying a route-policy.

Use the additional-path selection command with an appropriate route-policy to calculate backup paths and to enable Prefix Independent Convergence (PIC) functionality. Refer BGP Prefix Independent Convergence Unipath Primary/Backup section in Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide for details on the PIC functionality.

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to enable selection of additional paths:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# additional-paths selection route-policy ap1 

This example shows how to disable add-path selection for a particular VRF address-family (vrf1):
RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config-bgp)#vrf vrf1
RP/0/RSP0/CPU0:router(config-bgp-vrf)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-vrf-af)#additional-paths selection disable
This example shows how to enable add-path selection for a particular VRF address-family (vrf2):
RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config-bgp)#vrf vrf2
RP/0/RSP0/CPU0:router(config-bgp-vrf)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-vrf-af)#additional-paths selection route-policy ap2

additional-paths send

To configure send capability of multiple paths for a prefix to the capable peers, use the additional-paths send command in address-family configuration mode. To disable the send capability, use the no form of this command.

additional-paths send [disable]

no additional-paths send

Syntax Description

disable

Disables advertising additional paths send capability.
Note   

Use the disable option to disable add-path send capability for all neighbors belonging to a particular VRF address-family.

Command Default

None

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Use the additional-paths send command to allow add-path send capability to be negotiated for a specified address family. When the additional-paths send command is configured, the send capability is automatically enabled for all internal BGP neighbors for the specified address family. When the command is either not configured or explicitly disabled, none of the neighbors are allowed to negotiate send capability for the address family.

After enabling the send capability, the session needs to be reset for the configuration to take into effect.

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to enable additional paths send capability under VPNv4 4 unicast address family:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:routerconfig)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# additional-paths send

This example shows how to enable add-path selection for a particular VRF address-family (vrf1):
RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config-bgp)#vrf vrf1
RP/0/RSP0/CPU0:router(config-bgp-vrf)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-vrf-af)#additional-paths send disable

Related Commands

Command

Description

additional-paths receive

Configures receive capability of multiple paths for a prefix to the capable peers.  

capability additional-paths send

Advertises capability of sending additional paths to the peer.  

capability additional-paths receive

Advertises additional paths receive capability.  

address-family (BGP)

To enter various address family configuration modes while configuring Border Gateway Protocol (BGP), use the address-family command in an appropriate configuration mode. To disable support for an address family, use the no form of this command.

address-family { ipv4 { labeled-unicast | multicast | unicast } | ipv6 { unicast } | l2vpn vpls-vpws | vpnv4 { unicast } | vpnv6 {unicast | } }

no address-family

Syntax Description

ipv4 unicast

Specifies IP Version 4 (IPv4) unicast address prefixes.

ipv4 multicast

Specifies IPv4 multicast address prefixes.

ipv4 labeled-unicast

Specifies IPv4 labeled-unicast address prefixes. This option is available in IPv4 neighbor configuration mode and VRF neighbor configuration mode.

ipv6 unicast

Specifies IP Version 6 (IPv6) unicast address prefixes.

vpnv4 unicast

Specifies VPN Version 4 (VPNv4) unicast address prefixes. This option is not available in VRF or VRF neighbor configuration mode.

l2vpn vpls-vpws

Specifies L2VPN vpls-vpws address prefixes.

Command Default

An address family must be explicitly configured in the router configuration mode for the address family to be active in BGP. Similarly, an address family must be configured under the neighbor for the BGP session to be established for that address family. An address family must be configured in router configuration mode before it can be configured under a neighbor.

Command Modes

Router configuration

Neighbor configuration

Neighbor group configuration

VRF configuration

VRF neighbor configuration (IPv4 address families)

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

L2VPN Address Family support was added.

Usage Guidelines

Use the address-family command to enter various address family configuration modes while configuring BGP routing sessions. When you enter the address-family command from router configuration mode, you enable the address family and enter global address family configuration mode.

The IPv4 unicast address family must be configured in router configuration mode before configuring the IPv4 labeled-unicast address family for a neighbor in neighbor configuration mode. See Table 1.

Table 1 Address Family Submode Support

Address Family

Supported in Router Submode

Supported in Neighbor Submode

Comments

ipv4 unicast

yes

yes

ipv4 multicast

yes

yes

ipv4 labeled-unicast

no

yes

The ipv4 labeled-unicast address family can be configured only as a neighbor address family; however, it requires that the ipv4 unicast address family be configured as the router address family first.

vpnv4 unicast

yes

yes

ipv6 unicast

yes

yes

ipv6 multicast

yes

yes

l2vpn vpls-vpws

yes

yes

When you enter the address-family command from neighbor configuration mode, you activate the address family on the neighbor and enter neighbor address family configuration mode. IPv4 neighbor sessions support IPv4 unicast, multicast, labeled-unicast, and VPNv4 unicast address families. IPv6 neighbor sessions support IPv6 unicast address families.

Outbound Route Filter (ORF) capability is not supported with address-family l2vpn vpls-vpws

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to place the router in global address family configuration mode for the IPv4 address family:

RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)#  

The following example shows how to activate IPv4 multicast for neighbor 10.0.0.1 and place the router in neighbor address family configuration mode for the IPv4 multicast address family:
RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:routerrouter bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-af)# exit 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# 
  
The following example shows how to place the router in global address family configuration mode for the IPv4 tunnel address family:
RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 12
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 tunnel
RP/0/RSP0/CPU0:router(config-bgp-af)#  

advertise best-external

To advertise the best–external path to the iBGP and route-reflector peers, when a locally selected bestpath is from an internal peer, use the advertise best-external command in an appropriate address family configuration mode. To prevent advertising the best–external path, use the no form of this command. To disable advertising the best–external path, use the disable keyword.

advertise best-external [disable]

no advertise best-external

Syntax Description

disable

Disables best–external configuration for the VRF.

Command Default

None

Command Modes

VRF IPv4 address family configuration

VRF IPv6 address family configuration

L2VPN address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

IPv4 address family configuration

IPv6 address family configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Release 4.0.0

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable advertising the best–external path VPNv4 unicast address family mode:

RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# advertise best-external
  
 

Related Commands

Command

Description

additional-paths install backup

Installs a backup path into the forwarding table and provides prefix independent convergence (PIC) in case of a PE-CE link failure.

retain local-label

Retains the local label until the network is converged.

advertisement-interval

To set the minimum interval between the sending of Border Gateway Protocol (BGP) routing updates, use the advertisement-interval command in an appropriate configuration mode. To remove the advertisement-interval command from the configuration file and restore the system to its default interval values, use the no form of this command.

advertisement-interval seconds

no advertisement-interval [seconds]

Syntax Description

seconds

Minimum interval between sending BGP routing updates (in seconds). Range is 0 to 600.

Command Default

Default minimum interval:

For internal BGP (iBGP) peers is 0 seconds

For external BGP (eBGP) peers is 30 seconds

For customer edge (CE) peers is 0 seconds

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

VRF neighbor configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 5.0.0

This command was introduced.

Usage Guidelines

If this command configures a neighbor group or session group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the minimum time between sending BGP routing updates to 10 seconds:

RP/0/RSP0/CPU0:router(config)# router bgp 5
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.1.1.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 100
RP/0/RSP0/CPU0:router(config-bgp-nbr)# advertisement-interval 10

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

session-group

Creates a session group and enters session group configuration mode.

af-group

To create an address family group for Border Gateway Protocol (BGP) neighbors and enter address family group configuration mode, use the af-group command in router configuration mode. To remove an address family group, use the no form of this command.

af-group af-group-name address-family

no af-group

Syntax Description

af-group-name

Address family group name.

address-family

Enters address family configuration mode.

ipv4 unicast

Specifies IP Version 4 (IPv4) unicast address prefixes.

ipv4 multicast

Specifies IPv4 multicast address prefixes.

ipv4 labeled-unicast

Specifies IPv4 labeled unicast address prefixes.

ipv4 tunnel

Specifies IPv4 tunnel address prefixes.

ipv6 unicast

Specifies IP Version 6 (IPv6) unicast address prefixes.

vpnv4 unicast

Specifies VPN Version 4 (VPNv4) unicast address prefixes.

Command Default

No BGP address family group is configured.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the af-group command to group address family-specific neighbor commands within an IPv4 or IPv6 address family. Neighbors that have address family configuration are able to use the address family group. Further, neighbors inherit the configuration parameters of the entire address family group.

You cannot define two address family groups with the same name in different address families.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to create address family group group1 and enter address family group configuration mode for IPv4 unicast. Group1 contains the next-hop-self feature, which is inherited by neighbors that use address family group1.

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# next-hop-self

Related Commands

Command

Description

neighbor (BGP)

Enters neighbor configuration mode for configuring BGP routing sessions.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

session-group

Creates a session group and enters session group configuration mode.

use

Inherits configuration from a neighbor group, session group, or address family group.

aggregate-address

To create an aggregate entry in a Border Gateway Protocol (BGP) routing table, use the aggregate-address command in an appropriate configuration mode. To remove the aggregate-address command from the configuration file and restore the system to its default condition, use the no form of this command.

aggregate-address address/mask-length [as-set] [as-confed-set] [summary-only] [route-policy route-policy-name ]

no aggregate-address

Syntax Description

address

Aggregate address.

/mask-length

Aggregate address mask length.

as-set

(Optional) Generates autonomous system set path information and community information from contributing paths.

as-confed-set

(Optional) Generates autonomous system confederation set path information from contributing paths.

summary-only

(Optional) Filters all more-specific routes from updates.

route-policy route-policy-name

(Optional) Specifies the name of a route policy used to set the attributes of the aggregate route.

Command Default

When you do not specify this command, no aggregate entry is created in the BGP routing table.

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

You can implement aggregate routing in BGP either by redistributing an aggregate route into BGP using the network command or the aggregate-address command.

Use the aggregate-address command without optional arguments to create an aggregate entry in the BGP routing table if any more-specific BGP routes are available that fall in the specified range. The aggregate route is advertised as coming from your autonomous system and has the atomic aggregate attribute set to show that information might be missing. (By default, the atomic aggregate attribute is set unless you specify the as-set keyword.)

Use of the as-set keyword creates an aggregate entry using the same rules that the command follows without this keyword. However, the advertised path for this route is an AS_SET, a set of all autonomous systems contained in all paths that are being summarized.

Do not use this form of the aggregate-address command when aggregating many paths because this route must be continually withdrawn and updated as autonomous system path reachability information for the summarized routes changes.

Use the as-confed-set keyword to create an AS_CONFED_SET in the autonomous system path of the aggregate from any confederation segments in the paths being summarized. This keyword takes effect only if the as-set keyword is also specified.

Use of the summary-only keyword creates an aggregate entry (for example, 10.0.0.0/8) but suppresses advertisements of more-specific routes to all neighbors. If you want to suppress only advertisements to certain neighbors, use the route-policy (BGP) command in neighbor address family configuration mode with caution. If a more-specific route leaks out, all BGP speakers (the local router) prefer that route over the less-specific aggregate you generate (using longest-match routing).

Use the route-policy keyword to specify a routing policy for the aggregate entry. The route-policy keyword is used to select which more-specific information to base the aggregate entry on and which more-specific information to suppress. You can also use the keyword to modify the attributes of the aggregate entry.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to create an aggregate address. The path advertised for this route is an autonomous system set consisting of all elements contained in all paths that are being summarized.

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# aggregate-address 10.0.0.0/8 as-set

Related Commands

Command

Description

network (BGP)

Specifies the list of networks for the BGP routing process.

route-policy (BGP)

Applies a routing policy to updates advertised to or received from a BGP neighbor

route-policy (RPL)

Defines a route policy and enters route-policy configuration mode.

aigp

To enable sending and receiving of accumulated interior gateway protocol (AiGP) attribute per eBGP neighbor, use the aigpcommand in appropriate configuration mode. To disable this functionality, either use the disable keyword or use the no form of this command.

aigp [ disable ]

no aigp

Syntax Description

disable

Disables sending or receiving AiGP attribute.

Command Default

Send or recive of AiGP attribute is disabled for eBGP neighbors

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

Neighbor address family configuration

VRF neighbor address family configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Task ID

Task ID Operation
bgp

read, write

Examples

The following example shows how to enable AiGP send and receive capability under neighbor address family (IPv4 unicast):

RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.2.3.4
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# aigp

Related Commands

Command Description
aigp send-cost-community

Sends AiGP value in cost community.

aigp send-cost-community

To send Accumulated Interior Gateway Protocol (AiGP) value in cost community, use the aigp send-cost-community command in appropriate configuration mode. To disable sending AiGP value in cost community, either use the no form of this command or the disable keyword.

aigp send-cost-community { cost-id | disable } poi { igp-cost | pre-bestpath } [ transitive ]

no aigp send-cost-community

Syntax Description

cost-comm-id

Specifies the Cost community ID. The range is 0 to 255.

poi Point of insertion for bestpath calculation.
igp-cost Configures that cost community be used after iGP distance to next hop.
pre-bestpath Configures cost community as first step in best path calculation.
transitive

(Optional) Enables transitive cost community

disable

Disables sending AiGP value in cost community.

Command Default

Sending AiGP value in cost community is disabled

Command Modes

Neighbor address family configuration

VRF neighbor address family configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Cost community point of insertion can be configured either to be pre-bestpath or after igp cost. The transitive keyword is not required for iBGP sessions. However, the transitive keyword is required for eBGP sessions to convert AiGP metric into cost-community and advertise to the eBGP neighbors.

Task ID

Task ID Operation
bgp

read, write

Examples

The following example shows how to enable sending AiGP value in cost community ID 254 under neighbor address family (IPv4 unicast):

RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.2.3.4
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# aigp send-cost-community 254

Related Commands

Command Description
aigp Enables sending and receiving of accumulated interior gateway protocol (AiGP) attribute.

allocate-label

To allocate Multiprotocol Label Switching (MPLS) labels for specific IPv4 unicast or IPv6 unicast or VPN routing and forwarding (VRF) IPv4 unicast routes so that the BGP router can send labels with BGP routes to a neighboring router configured for labeledunicast sessions, use the allocate-label command in the appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

allocate-label { route-policy route-policy-name | all }

no allocate-label { route-policy route-policy-name | all }

Syntax Description

all

Allocates labels for all prefixes

route-policy route-policy-name

Uses a route policy to select prefixes for label allocation.

Command Default

No default behavior or values

Command Modes

IPv4 address family configuration

VRF IPv4 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the allocate-label command with a route policy to trigger BGP to allocate labels for all or a filtered set of global IPv4 routes (as dictated by the route policy). The command enables autonomous system border routers (ASBRs) that have labeled IPv4 unicast sessions to exchange Multiprotocol Label Switching (MPLS) labels with the IPv4 routes to the other autonomous system (AS) in Layer 3 Virtual Private Network (L3VPN) inter-AS deployments.


Note


The allocate-label all command is functionally equivalent to the allocate-label route-policy route-policy-name command when the route policy is a pass-all policy.


See Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guidefor information on using the allocate-label command for L3VPN inter-AS deployments and carrier-supporting-carrier IPv4 BGP label distribution.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable allocating labels for IPv4 routes:

RP/0/RSP0/CPU0:router(config)# router bgp 6
RP/0/RSP0/CPU0:router(config-bgp)# address family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# allocate-label route-policy policy_A

allowas-in

To allow an AS path with the provider edge (PE) autonomous system number (ASN) a specified number of times, use the allowas-in command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

allowas-in [as-occurrence-number]

no allowas-in [as-occurrence-number]

Syntax Description

as-occurrence-number

(Optional) Number of times a PE ASN is allowed. Range is 1 to 10.

Command Default

No default behavior or values

Command Modes

Address family group configuration

Neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Hub and spoke VPN networks require looping back of routing information to the hub PE through the hub customer edge (CE). See Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide for information on hub and spoke VPN networks. This looping back, in addition to the presence of the PE ASN, causes the looped-back information to be dropped by the hub PE.

The allowas-in command prevents the looped-back information from being dropped by replacing the neighbor autonomous system number (ASN) with the PE ASN in the AS path. This allows the VPN customer to see a specified number of occurrences of the PE ASN in the AS path.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to allow five occurrences of the PE ASN:

RP/0/RSP0/CPU0:router(config)# router bgp 6
RP/0/RSP0/CPU0:router(config-bgp)# af-group group_1 address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# allowas-in 5

as-format

To configure the router's Autonomous system number (ASN) notation to asdot format, use the as-format command in global configuration mode. To restore the system to its default condition, use the no form of this command.

as-format asdot

no

Syntax Description

asdot

Specifies the Autonomous system number (ASN) notation to asdot format.

Command Default

The default value, if the as-format command is not configured, is asplain.

Command Modes

Global configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the ASN notation to the asdot format:

RP/0/RSP0/CPU0:router(config)# as-format asdot

as-override

To configure a provider edge (PE) router to override the autonomous system number (ASN) of a site with the ASN of a provider, use the as-override command in VRF neighbor address family configuration mode. To restore the system to its default condition, use the no form of this command.

as-override [inheritance-disable]

no as-override [inheritance-disable]

Syntax Description

inheritance-disable

(Optional) Prevents the as-override command from being inherited from a parent group.

Command Default

Automatic override of the ASN is disabled.

Command Modes

VRF neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

Use the as-override command in conjunction with the site-of-origin (SoO) feature, identifying the site where a route originated, and preventing routing loops between routers within a VPN.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure an ASN override:

RP/0/RSP0/CPU0:router(config)# router bgp 6
RP/0/RSP0/CPU0:router(config-bgp)# vrf vrf_A 
RP/0/RSP0/CPU0:router(config-bgp-vrf)# neighbor 192.168.70.24
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr)# remote-as 10 
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr-af)# as-override 

 

Related Commands

Command

Description

site-of-origin (BGP)

Configures the site of origin filtering.

as-path-loopcheck out disable

To disable AS PATH loop checking for outbound updates, use the as-path-loopcheck out disable command in an appropriate address family configuration mode. To re-enable the default AS PATH loop checking, use the no form of this command.

as-path-loopcheck out disable

no as-path-loopcheck out disable

Syntax Description

This command has no keywords or arguments.

Command Default

AS PATH loop checking for outbound updates is enabled if there is only one neighbor and disabled if there are multiple neighbors in the update group.

Command Modes

IPv4 address family

IPv6 address family

L2VPN address family

VPNv4 address family

VPNv6 address family

Command History

Release Modification

Release 3.8.2

This command was introduced.

Usage Guidelines

Configure the as-path-loopcheck out disable command to disable the default behavior of PE router not announcing BGP routes to the CE router if the routes contain an AS number matching the AS number of the receiving CE router.

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to configure as-path-loopcheck out disable under IPv6 unicast address family:

RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#address-family ipv6 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)#as-path-loopcheck out disable

bfd (BGP)

To specify a bidirectional forwarding detection (BFD) multiplier and minimum-interval arguments per neighbor, use the bfd command in neighbor address family independent configuration mode. To return to the system defaults, use the no form of this command.

Previous to this enhancement, BFD could be configured only in global scope in BGP. This change makes available two new command-line arguments under neighbor address family independent configuration:

bfd { multiplier | | minimum-interval } value

no bfd { multiplier | | minimum-interval } value

Syntax Description

multiplier value

Specifies the BFD session's multiplier value for the neighbor.

minimum-interval value

Specifies the BFD session's minimum-interval value for the neighbor.

Command Default

No default per neighbor parameters are set.

Command Modes

Neighbor address family independent configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

If the minimum interval is changed using the bfd minimum-intervalcommand, the new parameter updates all affected BFD sessions under the command mode in which the minimum interval was changed.

If the multiplier is changed using the bfd multiplier command, the new parameter is used to update only the BFD sessions associated with the affected neighbor gets affected.

The assumption is that when BFD fast-detect is enabled under neighbor address family independent configuration, the values for the multiplier and minimum-interval values are always derived from the per-neighbor values if they are configured; otherwise, they are to be taken from the global BGP configuration mode. In the event that this has not been explicitly stated, then these values are taken to be the default values. Also, the bfd arguments can be configured under neighbor-group and session-group and the inheritance adheres to the standard way of BGP configuration inheritance.

Accordingly, there are four cases in which bfd-fast detect is enabled.

This is shown in table below where the BFD value is either multiplier or minimum-interval. Local indicates per NBR value, global is the BGP global value.

BFD value (global)

BFD value (local)

Result

Yes

Yes

BFD value (local)

Yes

No

BFD value (global)

No

Yes

BFD value (local)

No

No

BFD value (default)

Examples

The following example shows how to specify the BFD session's multiplier value for the neighbor:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# router bgp 65000
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)#neighbor 3.3.3.2 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# bfd minimum-interval 311
RP/0/RSP0/CPU0:router(config-bgp-nbr)# bfd multiplier 7
RP/0/RSP0/CPU0:router(config-bgp-nbr)# neighbor 5.5.5.2
RP/0/RSP0/CPU0:router(config-bgp-nbr)# bfd minimum-interval 318
RP/0/RSP0/CPU0:router(config-bgp-nbr)# bfd multiplier 4
RP/0/RSP0/CPU0:router(config-bgp-nbr)# vrf one
RP/0/RSP0/CPU0:router(config-bgp-vrf)# neighbor 3.12.1.2
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr)# bfd minimum-interval 119
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr)# bfd multiplier 10
RP/0/RSP0/CPU0:router(config-bgp-vrf-nbr)# commit
    
  RP/0/RSP0/CPU0:router# show bfd session
  Interface            Dest Addr           Local det time(int*mult)      State
                                             Echo            Async
  -------------------- --------------- ---------------- ---------------- ---------
  Gi0/2/0/2            3.3.3.2         2177ms(311ms*7)  14s(2s*7)        UP
  Gi0/2/0/2.1          3.12.1.2        1190ms(119ms*10) 20s(2s*10)       UP
  PO0/3/0/6            5.5.5.2         1272ms(318ms*4)  8s(2s*4)         UP
  
  
  RP/0/RSP0/CPU0:router# show bfd session detail
  I/f: GigabitEthernet0/2/0/2, Location: 0/2/CPU0, dest: 3.3.3.2, src: 3.3.3.1
   State: UP for 0d:0h:4m:44s, number of times UP: 1
  Received parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 7, diag: None
   My discr: 524295, your discr: 524296, state UP, D/F/P/C/A: 0/0/0/1/0
  Transmitted parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 7, diag: None
   My discr: 524296, your discr: 524295, state UP, D/F/P/C/A: 0/0/0/1/0
  Timer Values:
   Local negotiated async tx interval: 2 s
   Remote negotiated async tx interval: 2 s
   Desired echo tx interval: 311 ms, local negotiated echo tx interval: 311 ms
   Echo detection time: 2177 ms(311 ms*7), async detection time: 14 s(2 s*7)
  Local Stats:
   Intervals between async packets:
     Tx: Number of intervals=100, min=1664 ms, max=2001 ms, avg=1838 ms
         Last packet transmitted 313 ms ago
     Rx: Number of intervals=100, min=1662 ms, max=2 s, avg=1828 ms
         Last packet received 1615 ms ago
   Intervals between echo packets:
     Tx: Number of intervals=100, min=181 ms, max=462 ms, avg=229 ms
         Last packet transmitted 289 ms ago
     Rx: Number of intervals=100, min=178 ms, max=461 ms, avg=229 ms
         Last packet received 287 ms ago
   Latency of echo packets (time between tx and rx):
     Number of packets: 100, min=0 us, max=4 ms, avg=860 us
  Session owner information:
    Client           Desired interval         Multiplier
    ---------------- --------------------     --------------
    bgp-0            311 ms                   7
  
  I/f: GigabitEthernet0/2/0/2.1, Location: 0/2/CPU0, dest: 3.12.1.2, src: 3.12.1.1
   State: UP for 0d:0h:4m:44s, number of times UP: 1
  Received parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 10, diag: None
   My discr: 524296, your discr: 524295, state UP, D/F/P/C/A: 0/0/0/1/0
  Transmitted parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 10, diag: None
   My discr: 524295, your discr: 524296, state UP, D/F/P/C/A: 0/0/0/1/0
  Timer Values:
   Local negotiated async tx interval: 2 s
   Remote negotiated async tx interval: 2 s
   Desired echo tx interval: 119 ms, local negotiated echo tx interval: 119 ms
   Echo detection time: 1190 ms(119 ms*10), async detection time: 20 s(2 s*10)
  Local Stats:
   Intervals between async packets:
     Tx: Number of intervals=100, min=1664 ms, max=2001 ms, avg=1838 ms
         Last packet transmitted 314 ms ago
     Rx: Number of intervals=100, min=1662 ms, max=2 s, avg=1828 ms
         Last packet received 1616 ms ago
   Intervals between echo packets:
     Tx: Number of intervals=100, min=120 ms, max=223 ms, avg=125 ms
         Last packet transmitted 112 ms ago
     Rx: Number of intervals=100, min=119 ms, max=223 ms, avg=125 ms
         Last packet received 110 ms ago
   Latency of echo packets (time between tx and rx):
     Number of packets: 100, min=0 us, max=2 ms, avg=850 us
  Session owner information:
    Client           Desired interval         Multiplier
    ---------------- --------------------     --------------
    bgp-0            119 ms                   10
  
  I/f: GigabitEthernet0/3/0/6, Location: 0/3/CPU0, dest: 5.5.5.2, src: 5.5.5.1
   State: UP for 0d:0h:4m:50s, number of times UP: 1
  Received parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 4, diag: None
   My discr: 786436, your discr: 786433, state UP, D/F/P/C/A: 0/0/0/1/0
  Transmitted parameters:
   Version: 1, desired tx interval: 2 s, required rx interval: 2 s
   Required echo rx interval: 1 ms, multiplier: 4, diag: None
   My discr: 786433, your discr: 786436, state UP, D/F/P/C/A: 0/0/0/1/0
  Timer Values:
   Local negotiated async tx interval: 2 s
   Remote negotiated async tx interval: 2 s
   Desired echo tx interval: 318 ms, local negotiated echo tx interval: 318 ms
   Echo detection time: 1272 ms(318 ms*4), async detection time: 8 s(2 s*4)
  Local Stats:
   Intervals between async packets:
     Tx: Number of intervals=100, min=1663 ms, max=2 s, avg=1821 ms
         Last packet transmitted 1740 ms ago
     Rx: Number of intervals=100, min=1663 ms, max=2001 ms, avg=1832 ms
         Last packet received 160 ms ago
   Intervals between echo packets:
     Tx: Number of intervals=100, min=181 ms, max=484 ms, avg=232 ms
         Last packet transmitted 44 ms ago
     Rx: Number of intervals=100, min=179 ms, max=484 ms, avg=232 ms
         Last packet received 41 ms ago
   Latency of echo packets (time between tx and rx):
     Number of packets: 100, min=0 us, max=3 ms, avg=540 us
  Session owner information:
    Client           Desired interval         Multiplier
    ---------------- --------------------     --------------
    bgp-0            318 ms                   4
  
  RP/0/RSP0/CPU0:router# show bgp nei 3.3.3.2
  
  BGP neighbor is 3.3.3.2
   Remote AS 500, local AS 65000, external link
   Remote router ID 16.0.0.1
    BGP state = Established, up for 00:05:01 
    BFD enabled (session up): mininterval: 311 multiplier: 7
    Last read 00:00:56, hold time is 180, keepalive interval is 60 seconds
    Precedence: internet
    Neighbor capabilities:
      Route refresh: advertised and received
      4-byte AS: advertised and received
      Address family IPv4 Unicast: advertised and received
    Received 8 messages, 0 notifications, 0 in queue
    Sent 9 messages, 1 notifications, 0 in queue
    Minimum time between advertisement runs is 30 seconds
   
   For Address Family: IPv4 Unicast
    BGP neighbor version 2
    Update group: 0.2
    AF-dependant capabilities:
      Graceful Restart Capability advertised and received
        Neighbor preserved the forwarding state during latest restart
        Local restart time is 120, RIB purge time is 600 seconds
        Maximum stalepath time is 360 seconds
        Remote Restart time is 120 seconds
    Route refresh request: received 0, sent 0
    Policy for incoming advertisements is pass-all
    Policy for outgoing advertisements is pass-all
    1 accepted prefixes, 1 are bestpaths
    Prefix advertised 1, suppressed 0, withdrawn 0, maximum limit 524288
    Threshold for warning message 75%
    An EoR was not received during read-only mode
  
    Connections established 1; dropped 0      
    Last reset 00:06:58, due to User clear requested (CEASE notification sent - administrative reset)
    Time since last notification sent to neighbor: 00:06:58
    Error Code: administrative reset
    Notification data sent:
      None
  
  RP/0/RSP0/CPU0:router# show bgp nei 5.5.5.2
  
  BGP neighbor is 5.5.5.2
   Remote AS 500, local AS 65000, external link
   Remote router ID 16.0.0.1
    BGP state = Established, up for 00:05:04
    BFD enabled (session up): mininterval: 318 multiplier: 4
    Last read 00:00:58, hold time is 180, keepalive interval is 60 seconds
    Precedence: internet
    Neighbor capabilities:
      Route refresh: advertised and received
      4-byte AS: advertised and received
      Address family IPv4 Unicast: advertised and received
    Received 8 messages, 0 notifications, 0 in queue
    Sent 9 messages, 1 notifications, 0 in queue
    Minimum time between advertisement runs is 30 seconds
  
   For Address Family: IPv4 Unicast
    BGP neighbor version 2
    Update group: 0.2
    AF-dependant capabilities:
      Graceful Restart Capability advertised and received
        Neighbor preserved the forwarding state during latest restart
        Local restart time is 120, RIB purge time is 600 seconds
        Maximum stalepath time is 360 seconds
        Remote Restart time is 120 seconds
    Route refresh request: received 0, sent 0
    Policy for incoming advertisements is pass-all
    Policy for outgoing advertisements is pass-all
    1 accepted prefixes, 0 are bestpaths
    Prefix advertised 1, suppressed 0, withdrawn 0, maximum limit 524288
    Threshold for warning message 75%
    An EoR was not received during read-only mode
  
    Connections established 1; dropped 0
    Last reset 00:07:01, due to User clear requested (CEASE notification sent - administrative reset)
    Time since last notification sent to neighbor: 00:07:01
    Error Code: administrative reset
    Notification data sent:
      None
  
  RP/0/RSP0/CPU0:router# show bgp vrf one nei 3.12.1.2
  
  BGP neighbor is 3.12.1.2, vrf one
   Remote AS 500, local AS 65000, external link
   Remote router ID 16.0.0.1
    BGP state = Established, up for 00:05:06
    BFD enabled (session up): mininterval: 119 multiplier: 10
    Last read 00:00:01, hold time is 180, keepalive interval is 60 seconds
    Precedence: internet
    Neighbor capabilities:
      Route refresh: advertised and received
      4-byte AS: advertised and received
      Address family IPv4 Unicast: advertised and received
    Received 9 messages, 0 notifications, 0 in queue
    Sent 9 messages, 1 notifications, 0 in queue
    Minimum time between advertisement runs is 0 seconds
  
   For Address Family: IPv4 Unicast
    BGP neighbor version 2
    Update group: 0.2
    AF-dependant capabilities:
      Graceful Restart Capability advertised and received
        Neighbor preserved the forwarding state during latest restart
        Local restart time is 120, RIB purge time is 600 seconds
        Maximum stalepath time is 360 seconds
        Remote Restart time is 120 seconds
    Route refresh request: received 0, sent 0
    Policy for incoming advertisements is pass-all
    Policy for outgoing advertisements is pass-all
    1 accepted prefixes, 1 are bestpaths
    Prefix advertised 0, suppressed 0, withdrawn 0, maximum limit 524288
    Threshold for warning message 75%
    An EoR was not received during read-only mode
  
    Connections established 1; dropped 0 
    Last reset 00:07:04, due to User clear requested (CEASE notification sent - administrative reset)
    Time since last notification sent to neighbor: 00:07:04
    Error Code: administrative reset
    Notification data sent:
      None
  
  

bgp as-path-loopcheck

To enable loop checking in the autonomous system path of the prefixes advertised by internal Border Gateway Protocol (iBGP) peers, use the bgp as-path-loopcheck command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

bgp as-path-loopcheck

no bgp as-path-loopcheck

Syntax Description

This command has no keywords or arguments.

Command Default

When you do not specify this command, loop checking is performed only for external peers.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure an autonomous system path for loop checking iBGP peers:

RP/0/RSP0/CPU0:router(config)# router bgp 6
RP/0/RSP0/CPU0:router(config-bgp)# bgp as-path-loopcheck

bgp attribute-download

To enable Border Gateway Protocol (BGP) attribute download, use the bgp attribute-download command in an appropriate configuration mode. To disable BGP attribute download, use the no form of this command.

bgp attribute-download

no bgp attribute-download

Syntax Description

This command has no keywords or arguments.

Command Default

BGP attribute download is not enabled.

Command Modes

IPv4 unicast address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

When BGP attribute download is enabled using the bgp attribute-download command, BGP reinstalls all routes whose attributes are not currently in the RIB. Likewise, if the user disables BGP attribute download using the no form of the command, BGP reinstalls previously installed routes with a null key, and removes the attributes from the RIB.

Use the bgp attribute-download command to enable the Netflow BGP data export function. When attribute download is enabled, BGP downloads the attribute information for prefixes (community, extended community, and as-path) to the Routing Information Base (RIB) and Forwarding Information Base (FIB). This enables FIB to associate the prefixes with attributes and send the Netflow statistics along with the associated attributes.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows the BGP routes before and after BGP attribute download is enabled and shows how to enable BGP attribute download on BGP router 50:

  RP/0/RSP0/CPU0:router# show route bgp 
  
  B    100.0.1.0/24 [200/0] via 10.0.101.1, 00:00:37
  B    100.0.2.0/24 [200/0] via 10.0.101.1, 00:00:37
  B    100.0.3.0/24 [200/0] via 10.0.101.1, 00:00:37
  B    100.0.4.0/24 [200/0] via 10.0.101.1, 00:00:37
  B    100.0.5.0/24 [200/0] via 10.0.101.1, 00:00:37
  
  RP/0/RSP0/CPU0:router(config)# router bgp 50 
  RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
  RP/0/RSP0/CPU0:router(config-bgp-af)# bgp attribute-download
  !
  !
  !
  RP/0/RSP0/CPU0:router# show route bgp 
  
  B    100.0.1.0/24 [200/0] via 10.0.101.1, 00:00:01
        Attribute ID 0x2
  B    100.0.2.0/24 [200/0] via 10.0.101.1, 00:00:01
        Attribute ID 0x2
  B    100.0.3.0/24 [200/0] via 10.0.101.1, 00:00:01
        Attribute ID 0x2
  B    100.0.4.0/24 [200/0] via 10.0.101.1, 00:00:01
        Attribute ID 0x2
  B    100.0.5.0/24 [200/0] via 10.0.101.1, 00:00:01
        Attribute ID 0x2
  

bgp auto-policy-soft-reset disable

To disable an automatic soft reset of Border Gateway Protocol (BGP) peers when their configured route policy is modified, use the bgp auto-policy-soft-reset disable command in an appropriate configuration mode. To re-enable automatic soft reset of BGP peers, use the no form of this command.

bgp auto-policy-soft-reset disable

no bgp auto-policy-soft-reset disable

Syntax Description

This command has no keywords or arguments.

Command Default

Automatic soft reset of peers is enabled.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines


Note


If the inbound policy changes, it is not always possible to perform a soft reset. This is the case if the neighbor does not support route refresh and soft-reconfiguration inbound is not configured for the neighbor. In such instances, a message is logged in the system log indicating that a manual hard reset is needed.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable an automatic soft reset of BGP peers when their configured route policy is modified:

RP/0/RSP0/CPU0:router(config)# router bgp 6
RP/0/RSP0/CPU0:router(config-bgp)# bgp auto-policy-soft-reset disable

bgp bestpath as-path ignore

To ignore the autonomous system path length when calculating preferred paths, use the bgp bestpath as-path ignore command in an appropriate configuration mode. To return the software to the default state in which it considers the autonomous system path length when calculating preferred paths, use the no form of this command.

bgp bestpath as-path ignore

no bgp bestpath as-path ignore

Syntax Description

This command has no keywords or arguments.

Command Default

The autonomous system path length is used (not ignored) when a best path is selected.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp bestpath as-path ignore command to ignore the length of autonomous system paths when the software selects a preferred path. When the best path is selected, if this command is specified, all steps are performed as usual except comparison of the autonomous path length between candidate paths.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the software to ignore the autonomous system length when performing best-path selection:

RP/0/RSP0/CPU0:router(config)# router bgp 65000
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath as-path ignore

Related Commands

Command

Description

bgp bestpath compare-routerid

Compares identical routes received from eBGP peers during the best-path selection process and selects the route with the lowest router ID.

bgp bestpath med always

Allows the comparison of the Multi Exit Discriminator (MED) for paths from neighbors in different autonomous systems.

bgp bestpath med confed

Enables MED comparison among paths learned from confederation peers.

bgp bestpath med missing-as-worst

Enables the software to consider a missing MED attribute in a path as having a value of infinity.

bgp bestpath compare-routerid

To compare identical routes received from external BGP (eBGP) peers during the best-path selection process and select the route with the lowest router ID, use the bgp bestpath compare-routerid command in an appropriate configuration mode. To disable comparing identical routes received from eBGP peers during best-path selection, use the no form of this command.

bgp bestpath compare-routerid

no bgp bestpath compare-routerid

Syntax Description

This command has no keywords or arguments.

Command Default

The software does not select a new best path if it is the same as the current best path (according to the BGP selection algorithm) except for the router ID.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp bestpath compare-routerid command to affect how the software selects the best path, in the case where there are two paths of equal cost according to the BGP selection algorithm. This command is used to force the software to select the path with the lower router ID as the best path. If this command is not used, the software continues to use whichever path is currently the best path, regardless of which has the lower router ID.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the BGP speaker in autonomous system 500 to compare the router IDs of similar paths:

RP/0/RSP0/CPU0:router(config)# router bgp 500
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath compare-routerid

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

bgp bestpath cost-community ignore

To configure a router that is running the Border Gateway Protocol (BGP) to not evaluate the cost community attribute during the best-path selection process, use the bgp bestpath cost-community ignore command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

bgp bestpath cost-community ignore

no bgp bestpath cost-community ignore

Syntax Description

This command has no keywords or arguments.

Command Default

The behavior of this command is enabled by default until the cost community attribute is manually configured.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp bestpath cost-community ignore command to disable the evaluation of the cost community attribute to help isolate problems and troubleshoot issues that relate to BGP path selection. This command can also be used to delay the activation of cost community attribute evaluation so that cost community filtering can be deployed in a large network at the same time.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure a router to not evaluate the cost community attribute during the best-path selection process:

RP/0/RSP0/CPU0:router(config)# router bgp 500
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath cost-community ignore

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

bgp bestpath med always

To allow the comparison of the Multi Exit Discriminator (MED) for paths from neighbors in different autonomous systems, use the bgp bestpath med always command in an appropriate configuration mode. To disable considering the MED attribute in comparing paths, use the no form of this command.

bgp bestpath med always

no bgp bestpath med always

Syntax Description

This command has no keywords or arguments.

Command Default

The software does not compare MEDs for paths from neighbors in different autonomous systems.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

The MED is one of the parameters that is considered by the software when selecting the best path among many alternative paths. The software chooses the path with the lowest MED.

By default, during the best-path selection process, the software makes a MED comparison only among paths from the same autonomous system. This command changes the default behavior of the software by allowing comparison of MEDs among paths regardless of the autonomous system from which the paths are received.

When the bgp bestpath med always command is not enabled and distributed BGP is configured, speakers calculate partial best paths only (executes the best-path steps up to the MED comparison) and send them to BGP Routing Information Base (bRIB). bRIB calculates the final best path (executes all the steps in the best-path calculation). When the bgp bestpath med always command is enabled and distributed BGP is configured, speakers can compare the MED across all ASs, allowing the speaker to calculate a single best path to send it to bRIB. bRIB is the ultimate process that calculates the final best path, but when the bgp bestpath med always command is enabled, the speakers send a single best path instead of potentially sending multiple, partial best paths

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the Border Gateway Protocol (BGP) speaker in autonomous system 100 to compare MEDs among alternative paths, regardless of the autonomous system from which the paths are received:

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath med always

Related Commands

Command

Description

bgp bestpath med confed

Enables MED comparison among paths learned from confederation peers.

bgp bestpath med missing-as-worst

Specifies that the software consider a missing MED attribute in a path as having a value of infinity, making the path without a MED value the least desirable path.

show bgp

Displays entries in the BGP routing table.

bgp bestpath med confed

To enable Multi Exit Discriminator (MED) comparison among paths learned from confederation peers, use the bgp bestpath med confed command in an appropriate configuration mode. To disable the software from considering the MED attribute in comparing paths, use the no form of this command.

bgp bestpath med confed

no bgp bestpath med confed

Syntax Description

This command has no keywords or arguments.

Command Default

The software does not compare the MED of paths containing only confederation segments, or paths containing confederation segments followed by an AS_SET, with the MED of any other paths.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

By default, the MED of the following paths is not compared with the MED of any other path:

  • Paths with an empty autonomous system path
  • Paths beginning with an AS_SET
  • Paths containing only confederation segments
  • Paths containing confederation segments followed by an AS_SET

Use the bgp bestpath med confed command to affect how the following types of paths are treated in the BGP best-path algorithm:

  • Paths containing only confederation segments
  • Paths containing confederation segments followed by an AS_SET

The MED for paths that start with an AS_SEQUENCE or that start with confederation segments followed by an AS_SEQUENCE only is compared with the MED of other paths that share the same first autonomous system number in the autonomous system sequence (the neighbor autonomous system number). This behavior is not affected by the bgp bestpath med confed command.

As an example, suppose that autonomous systems 65000, 65001, 65002, and 65004 are part of a confederation, but autonomous system 1 is not. Suppose that for a particular route, the following paths exist:

  • Path 1: 65000 65004, med = 2, IGP metric = 20
  • Path 2: 65001 65004, med = 3, IGP metric = 10
  • Path 3: 65002 1, med = 1, IGP metric = 30

If the bgp bestpath med confed command is enabled, the software selects path 1 as the best path because it:

  • Has a lower MED than path 2
  • Has a lower IGP metric than path 3

The MED is not compared with path 3 because it has an external autonomous system number (that is, an AS_SEQUENCE) in the path. If the bgp bestpath med confed command is not enabled, then MED is not compared between any of these paths. Consequently, the software selects path 2 as the best path because it has the lowest IGP metric.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following command shows how to enable Border Gateway Protocol (BGP) software to compare MED values for paths learned from confederation peers:

RP/0/RSP0/CPU0:router(config)# router bgp 210
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath med confed

Related Commands

Command

Description

bgp bestpath med always

Enables MED comparison among paths from neighbors in different autonomous systems.

bgp bestpath med missing-as-worst

Specifies that the software consider a missing MED attribute in a path as having a value of infinity, making the path without a MED value the least desirable path.

show bgp

Displays entries in the BGP routing table.

bgp bestpath med missing-as-worst

To have the software consider a missing Multi Exit Discriminator (MED) attribute in a path as having a value of infinity, making the path without a MED value the least desirable path, use the bgp bestpath med missing-as-worst command in an appropriate configuration mode. To disable considering the MED attribute in comparing paths, use the no form of this command.

bgp bestpath med missing-as-worst

no bgp bestpath med missing-as-worst

Syntax Description

This command has no keywords or arguments.

Command Default

The software assigns a value of 0 to the missing MED, causing the path with the missing MED attribute to be considered as the best possible MED.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to direct the Border Gateway Protocol (BGP) software to consider a missing MED attribute in a path as having a value of infinity, making this path the least desirable path:

RP/0/RSP0/CPU0:router(config)# router bgp 210
RP/0/RSP0/CPU0:router(config-bgp)# bgp bestpath med missing-as-worst

Related Commands

Command

Description

bgp bestpath med always

Enables MED comparison among paths from neighbors in different autonomous systems.

bgp bestpath med confed

Enables MED comparison among paths learned from confederation peers.

show bgp

Displays entries in the BGP routing table.

bgp client-to-client reflection disable

To disable reflection of routes between route-reflection clients using a Border Gateway Protocol (BGP) route reflector, use the bgp client-to-client reflection disable command in address family configuration mode. To re-enable client-to-client reflection, use the no form of this command.

bgp client-to-client reflection [cluster-id cluster-id] disable

no bgp client-to-client reflection [cluster-id cluster-id] disable

Syntax Description

This command has no keywords or arguments.

Command Default

Client-to-client reflection is enabled.

Command Modes

Address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

By default, the clients of a route reflector are not required to be fully meshed and the routes from a client are reflected to other clients. However, if the clients are fully meshed, route reflection is not required.

Examples

In this example, the three neighbors are fully meshed, so client-to-client reflection is disabled:

RP/0/RSP0/CPU0:router(config)# router bgp 65534
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)# bgp client-to-client reflection disable 
RP/0/RSP0/CPU0:router(config-bgp-af)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor-group rrclients
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# remote-as 65534
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# route-reflector-client 
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# exit
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# exit

RP/0/RSP0/CPU0:router(config-bgp)# neighbor 192.168.253.21 use neighbor-group rrclients
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 192.168.253.22 use neighbor-group rrclients

Related Commands

Command

Description

bgp cluster-id

Configures the cluster ID if the BGP cluster has more than one route reflector.

route-reflector-client

Configures the router as a BGP route reflector and configures the specified neighbor as its client.

show bgp

Displays entries in the BGP routing table.

bgp cluster-id

To configure the cluster ID if the Border Gateway Protocol (BGP) cluster has more than one route reflector, use the bgp cluster-id command in an appropriate configuration mode. To remove the cluster ID, use the no form of this command.

bgp cluster-id cluster-id

no bgp cluster-id [cluster-id]

Syntax Description

cluster-id

Cluster ID of this router acting as a route reflector; maximum of 4 bytes. Cluster ID can be entered either as an IP address or value. Range is 1 to 4294967295.

Command Default

A cluster ID is not configured.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Together, a route reflector and its clients form a cluster. A cluster of clients usually has a single route reflector. In such instances, the cluster is identified by the software as the router ID of the route reflector. To increase redundancy and avoid a single point of failure in the network, a cluster might have more than one route reflector. If it does, all route reflectors in the cluster must be configured with the same 4-byte cluster ID so that a route reflector can recognize updates from route reflectors in the same cluster.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the local router as one of the route reflectors serving the cluster. Neighbor 192.168.70.24 is assigned to the default cluster with cluster-id 1.

RP/0/RSP0/CPU0:router(config)# router bgp 65534
RP/0/RSP0/CPU0:router(config-bgp)# bgp cluster-id 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 192.168.70.24
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 65534
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast  
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# route-reflector-client 

Related Commands

Command

Description

route-reflector-client

Configures the router as a BGP route reflector and configures the specified neighbor as its client.

show bgp

Displays entries in the BGP routing table.

bgp confederation identifier

To specify a Border Gateway Protocol (BGP) confederation identifier, use the bgp confederation identifier command in an appropriate configuration mode. To remove the confederation identifier, use the no form of this command.

bgp confederation identifier as-number

no bgp confederation identifier [as-number]

Syntax Description

as-number

Autonomous system (AS) number that internally includes multiple autonomous systems.

  • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
  • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
  • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.

Command Default

No confederation identifier is configured.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

One way to reduce the internal BGP (iBGP) mesh is to divide an autonomous system into multiple autonomous systems and group them into a single confederation. Each autonomous system is fully meshed within itself, and has a few connections to another autonomous system in the same confederation. Although the peers in different autonomous systems have external BGP (eBGP) sessions, they exchange routing information as if they are iBGP peers. Specifically, the confederation maintains the next hop and local preference information, and that allows you to retain a single Interior Gateway Protocol (IGP) for all autonomous systems. To the outside world, the confederation looks like a single autonomous system.

Use the bgp confederation identifier command to specify the autonomous system number for the confederation. This autonomous system number is used when BGP sessions are established with external peers in autonomous systems that are not part of the confederation.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to divide the autonomous system into autonomous systems 4001, 4002, 4003, 4004, 4005, 4006, and 4007 with the confederation identifier 5. Neighbor 10.2.3.4 is a router inside the confederation. Neighbor 172.20.16.6 is outside the routing domain confederation. To the outside world, there appears to be a single autonomous system with the number 5.

RP/0/RSP0/CPU0:router(config)# router bgp 4001
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation identifier 5
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4002
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4003
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4004
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4005
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4006
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 4007
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.2.3.4
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 4002 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# exit
RP/0/RSP0/CPU0:router(config-bgp)# exit
RP/0/RSP0/CPU0:router(config-bgp-nbr)# neighbor 172.20.16.6 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 4009

Related Commands

Command

Description

bgp confederation peers

Configures the autonomous systems that belong to the confederation.

bgp confederation peers

To configure the autonomous systems that belong to the confederation, use the bgp confederation peers command in an appropriate configuration mode. To remove the autonomous system from the confederation, use the no form of this command.

bgp confederation peers [as-number]

no bgp confederation peers [as-number]

Syntax Description

as-number

Autonomous system (AS) numbers for Border Gateway Protocol (BGP) peers that belong to the confederation.

  • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
  • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
  • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.

Command Default

No BGP peers are identified as belonging to the confederation.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

The autonomous systems specified in this command are visible internally to a confederation. Each autonomous system is fully meshed within itself. The bgp confederation identifier command specifies the confederation to which the autonomous systems belong.

To specify multiple autonomous systems, enter BGP confederation peer configuration mode then enter one autonomous-system-number for each command line.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows that autonomous systems 1090 and 1093 belong to a single confederation:
RP/0/RSP0/CPU0:router(config)# router bgp 1090
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers 1093

The following example shows that autonomous systems 1095, 1096, 1097, and 1098 belong to a single confederation:

RP/0/RSP0/CPU0:router(config)# router bgp 1095
RP/0/RSP0/CPU0:router(config-bgp)# bgp confederation peers
RP/0/RSP0/CPU0:router(config-bgp-confed-peers)# 1096
RP/0/RSP0/CPU0:router(config-bgp-confed-peers)# 1097
RP/0/RSP0/CPU0:router(config-bgp-confed-peers)# 1098

Related Commands

Command

Description

bgp confederation identifier

Specifies a BGP confederation identifier.

bgp dampening

To enable Border Gateway Protocol (BGP) route dampening or change various BGP route dampening factors, use the bgp dampening command in an appropriate configuration mode. To disable route dampening and reset default values, use the no form of this command.

bgp dampening [ half-life [ reuse suppress max-suppress-time ] | route-policy route-policy-name ]

no bgp dampening [ half-life [ reuse suppress max-suppress-time ] | route-policy route-policy-name ]

Syntax Description

half-life

(Optional) Time (in minutes) after which a penalty is decreased. Once the route has been assigned a penalty, the penalty is decreased by half after the half-life period (which is 15 minutes by default). Penalty reduction happens every 5 seconds. Range of the half-life period is from 1 to 45 minutes.

reuse

(Optional) Value for route reuse if the flapping route penalty decreases and falls below the reuse value. When this happens, the route is unsuppressed. The process of unsuppressing routes occurs at 10-second increments. Range is 1 to 20000.

suppress

(Optional) Maximum penalty value. Suppress a route when its penalty exceeds the value specified. When this happens, the route is suppressed. Range is 1 to 20000.

max-suppress-time

(Optional) Maximum time (in minutes) a route can be suppressed. Range is 1 to 255. If the half-life value is allowed to default, the maximum suppress time defaults to 60 minutes.

route-policy route-policy-name

(Optional) Specifies the route policy to use to set dampening parameters.

Command Default

Route dampening is disabled.

half-life : 15 minutes

reuse : 750

suppress : 2000

max-suppress-time : four times half-life value

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VPNv4 address family configuration

VRF IPv4 address family configuration

VPNv6 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp dampening command without arguments to enable BGP route dampening with the default parameters. The parameters can be changed by setting them on the command line or specifying them with a routing policy.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the half-life value to 30 minutes, the reuse value to 1500, the suppress value to 10000, and the max-suppress-time to 120 minutes:

RP/0/RSP0/CPU0:router(config)# router bgp 50
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# bgp dampening 30 1500 10000 120

Related Commands

Command

Description

clear bgp dampening

Clears BGP route dampening information and unsuppresses the suppressed routes.

clear bgp flap-statistics

Clears BGP flap statistics.

route-policy (RPL)

Defines a route policy and enters route-policy configuration mode.

show bgp dampened-paths

Displays BGP dampened routes.

show bgp flap-statistics

Displays BGP flap statistics.

show bgp neighbors

Displays information about BGP connections to neighbors.

bgp default local-preference

To change the default local preference value, use the bgp default local-preference command in an appropriate configuration mode. To reset the local preference value to the default of 100, use the no form of this command.

bgp default local-preference value

no bgp default local-preference [value]

Syntax Description

value

Local preference value. Range is 0 to 4294967295. Higher values are preferable.

Command Default

Enabled with a value of 100.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

Generally, the default value of 100 allows you to easily define a particular path as less preferable than paths with no local preference attribute. The preference is sent to all networking devices in the local autonomous system.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to raise the default local preference value from the default of 100 to 200:
RP/0/RSP0/CPU0:router(config)# router bgp 200
RP/0/RSP0/CPU0:router(config-bgp)# bgp default local-preference 200

bgp enforce-first-as disable

To disable the software from enforcing the first autonomous system path (known as the AS path) of a route received from an external Border Gateway Protocol (eBGP) peer to be the same as the configured remote autonomous system, use the bgp enforce-first-as disable command in an appropriate configuration mode. To re-enable enforcing the first AS path of a received route from an eBGP peer to be the same as the remote autonomous system, use the no form of this command.

bgp enforce-first-as disable

no bgp enforce-first-as disable

Syntax Description

This command has no keywords or arguments.

Command Default

By default, the software requires the first autonomous system (in the AS path) of a route received from an eBGP peer to be the same as the remote autonomous system configured.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

By default, the software ignores any update received from an eBGP neighbor that does not have the autonomous system configured for that neighbor at the beginning of the AS path. When configured, the command applies to all eBGP peers of the router.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows a configuration in which incoming updates from eBGP neighbors are not checked to ensure the first AS number in the AS path is the same as the configured AS number for the neighbor:

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# bgp enforce-first-as disable

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

bgp fast-external-fallover disable

To disable immediately resetting the Border Gateway Protocol (BGP) sessions of any directly adjacent external peers if the link used to reach them goes down, use the bgp fast-external-fallover disable command in an appropriate configuration mode. To disable this function and perform an immediate reset of BGP sessions when a link between peers is lost, use the no form of this command.

bgp fast-external-fallover disable

no bgp fast-external-fallover disable

Syntax Description

disable

Disables BGP fast external failover.

Command Default

BGP sessions of any directly adjacent external peers are immediately reset if the link used to reach them goes down.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

By default, BGP sessions of any directly adjacent external peers are immediately reset, which allows the network to recover faster when links go down between BGP peers.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable the automatic resetting of BGP sessions:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# bgp fast-external-fallover disable

bgp graceful-restart

To enable graceful restart support, use the bgp graceful-restart command in an appropriate configuration mode. To disable this function, use the no form of this command.

bgp graceful-restart

no bgp graceful-restart

Syntax Description

This command has no keywords or arguments.

Command Default

Graceful restart support is not enabled.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp graceful-restart command to enable graceful restart functionality on the router, and also to advertise graceful restart to neighboring routers.


Note


The bgp graceful-restart command with no options must be used to enable graceful restart before using the bgp graceful-restart purge-time , bgp graceful-restart restart-time , bgp graceful-restart stalepath-time , or bgp graceful-restart graceful-reset commands.


When graceful restart is enabled, the BGP graceful restart capability is negotiated with neighbors in the BGP OPEN message when the session is established. If the neighbor also advertises support for graceful restart, then graceful restart is activated for that neighbor session. If the neighbor does not advertise support for graceful restart, then graceful restart is not activated for that neighbor session even though it is enabled locally.

If you enter the bgp graceful-restart command after some BGP sessions are established, you must restart those sessions before graceful restart takes effect. Use the clear bgp command to restart sessions.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable graceful restart:

RP/0/RSP0/CPU0:router(config)#router bgp 3 
RP/0/RSP0/CPU0:router(config-bgp)#bgp graceful-restart 

Related Commands

Command

Description

bgp graceful-restart graceful-reset

Enables a graceful reset if configuration changes force a peer reset.

bgp graceful-restart purge-time

Defines the maximum time before stale routes are purged.

bgp graceful-restart restart-time

Defines the maximum time advertised to neighbors

bgp graceful-restart stalepath-time

Defines the maximum time to wait for the End-of-RIB message from a neighbor that has been restarted before deleting learned routes.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about BGP connections to neighbors.

show bgp process

Displays BGP process information.

bgp graceful-restart graceful-reset

To invoke a graceful restart when configuration changes force a peer reset, use the bgp graceful-restart graceful-reset command in an appropriate configuration mode. To disable this function, use the no form of this command.

bgp graceful-restart graceful-reset

no bgp graceful-restart graceful-reset

Syntax Description

This command has no keywords or arguments.

Command Default

Graceful restart is not invoked when a configuration change forces a peer reset.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

BGP graceful restart must be enabled using the bgp graceful-restart command before enabling graceful reset using the bgp graceful-restart graceful-reset command.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable graceful reset:

RP/0/RSP0/CPU0:router(config)#router bgp 3 
RP/0/RSP0/CPU0:router(config-bgp)# bgp graceful-restart graceful-reset

Related Commands

Command

Description

bgp graceful-restart

Enables a graceful restart.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about BGP connections to neighbors.

show bgp process

Displays BGP process information.

bgp graceful-restart purge-time

To specify the maximum time before stale routes are purged from the routing information base (RIB) when the local BGP process restarts, use the bgp graceful-restart purge-time command in an appropriate configuration mode. To set the purge timer time to its default value, use the no form of this command.

bgp graceful-restart purge-time seconds

no bgp graceful-restart purge-time seconds

Syntax Description

seconds

Maximum time before stale routes are purged. Time in seconds. Range is 0 to 6000.

Command Default

seconds : 600

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

BGP graceful restart must be enabled using the bgp graceful-restart command before setting the purge time using the bgp graceful-restart purge-time command.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to change the BGP purge time to 800 seconds:

RP/0/RSP0/CPU0:router(config)# router bgp 3
RP/0/RSP0/CPU0:router(config-bgp)# bgp graceful-restart purge-time 800

Related Commands

Command

Description

bgp graceful-restart

Enables a graceful restart.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about BGP connections to neighbors.

show bgp process

Displays BGP process information.

bgp graceful-restart restart-time

To specify a user-predicted local BGP process maximum restart time, which is advertised to neighbors during session establishment, use the bgp graceful-restart restart-time command in an appropriate configuration mode. To set this restart time to its default value, use the no form of this command.

bgp graceful-restart restart-time seconds

no bgp graceful-restart restart-time seconds

Syntax Description

seconds

Maximum time advertised to neighbors. Time in seconds. Range is 1 to 4095.

Command Default

seconds : 120

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

BGP graceful restart must be enabled using the bgp graceful-restart command before setting the restart timer using the bgp graceful-restart restart-time command.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to change the BGP graceful restart time to 400 seconds:

RP/0/RSP0/CPU0:router(config)#router bgp 3 
RP/0/RSP0/CPU0:router(config-bgp)# bgp graceful-restart restart-time 400

Related Commands

Command

Description

bgp graceful-restart

Enables a graceful restart.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about BGP connections to neighbors.

show bgp process

Displays BGP process information.

bgp graceful-restart stalepath-time

To specify the maximum time to wait for an End-of-RIB message after a neighbor restarts, use the bgp graceful-restart stalepath-time command in an appropriate configuration mode. To set the stalepath timer time to its default value, use the no form of this command.

bgp graceful-restart stalepath-time seconds

no bgp graceful-restart stalepath-time seconds

Syntax Description

seconds

Maximum wait time. Time in seconds. Range is 1 to 4095.

Command Default

seconds : 360

Command Modes

Router configuration

Command History

Release

Modifications

Release 3.7.2

This command was introduced.

Usage Guidelines

BGP graceful restart must be enabled using the bgp graceful-restart command before setting the stalepath time using the bgp graceful-restart stalepath-time command.

If the stalepath time is exceeded before an End-of-RIB message is received from a neighbor, paths learned from the neighbor are purged from the BGP routing table.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to change the stalepath time to 750 seconds:

RP/0/RSP0/CPU0:router(config)# router bgp 3
RP/0/RSP0/CPU0:router(config-bgp)# bgp graceful-restart stalepath-time 750

Related Commands

Command

Description

bgp graceful-restart

Enables a graceful restart.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about BGP connections to neighbors.

show bgp process

Displays BGP process information.

bgp import-delay

To enable delay for Border Gateway Protocol (BGP) batch import processing, use the bgp import-delay command in an appropriate configuration mode. To disable delay in batch import processing, use the no form of this command.

bgp import-delay seconds milliseconds

no bgp import-delay

Syntax Description

seconds

Specifies batch import processing delay in seconds. Range is 0 to 10 seconds.

milliseconds

Specifies batch import processing delay in milliseconds. Range is 0 to 999 seconds.

Command Default

No delay is configured.

Command Modes

Address-family VPNv4 Unicast

Address-family VPNv6 Unicast

Command History

Release Modification
Release 3.9.1

This command was introduced.

Usage Guidelines

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to set delay in batch import processing as two seconds and zero milliseconds:

RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#address-family vpnv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)#bgp import-delay 2 0

Related Commands

Command

Description

bgp label-delay

Enables delay for Border Gateway Protocol (BGP) batch label processing  

bgp label-delay

To enable delay for Border Gateway Protocol (BGP) batch label processing, use the bgp label-delay command in an appropriate configuration mode. To disable delay in batch import processing, use the no form of this command.

bgp label-delay seconds milliseconds

no bgp label-delay

Syntax Description

seconds

Specifies batch label processing delay in seconds. Range is 0 to 10 seconds.

milliseconds

Specifies batch label processing delay in milliseconds. Range is 0 to 999 seconds.

Command Default

No delay is configured.

Command Modes

Address-family IPv4 Unicast

Address-family IPv6 Unicast

Address-family IPv4 Multicast

Address-family IPv6 Multicast

Address-family VPNv4 Unicast

Address-family VPNv6 Unicast

Command History

Release Modification
Release 3.9.1

This command was introduced.

Usage Guidelines

Task ID

Task ID Operation

bgp

read, write

Examples

This example shows how to set delay in batch import processing as two seconds and zero milliseconds:

RP/0/RSP0/CPU0:router#configure
RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)#bgp label-delay 2 0

Related Commands

Command

Description

bgp import-delay

Enables delay for Border Gateway Protocol (BGP) batch import processing  

bgp log neighbor changes disable

To disable logging of Border Gateway Protocol (BGP) neighbor resets, use the bgp log neighbor changes disable command in an appropriate configuration mode. To re-enable logging of BGP neighbor resets, use the no form of this command.

bgp log neighbor changes disable

no bgp log neighbor changes disable

Syntax Description

This command has no keywords or arguments.

Command Default

BGP neighbor changes are logged.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Logging of BGP neighbor status changes (up or down) and resets is used for troubleshooting network connectivity problems and measuring network stability. Unexpected neighbor resets might indicate high error rates or high packet loss in the network, and should be investigated.

Status change message logging does not substantially affect performance, unlike, for example, enabling per-BGP update debugging. If the UNIX syslog facility is enabled, messages are sent by the software to the UNIX host running the syslog daemon so that the messages can be stored and archived on disk. If the UNIX syslog facility is not enabled, the status change messages are kept in the internal buffer of the router, and are not stored to disk.

The neighbor status change messages are not tracked if the bgp log neighbor changes disable command is disabled, except for the last reset reason, which is always available as output of the show bgp neighbors command.

Up and down messages for BGP neighbors are logged by the software by default. Use the bgp log neighbor changes disable command to stop logging BGP neighbor changes.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to prevent the logging of neighbor changes for BGP:

RP/0/RSP0/CPU0:router(config)# router bgp 65530
RP/0/RSP0/CPU0:router(config-bgp)# bgp log neighbor changes disable

Related Commands

Command

Description

show bgp neighbors

Displays information about the TCP and BGP connections to neighbors.

bgp maximum neighbor

To control the maximum number of neighbors that can be configured on the router, use the bgp maximum neighbor command in an appropriate configuration mode. To set the neighbor limit to the default value, use the no form of this command.

bgp maximum neighbor limit

no maximum neighbor [limit]

Syntax Description

limit

Maximum number of neighbors. Range is 1 to 15000.

Command Default

Default limit is 4000

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Any attempt to configure the neighbor limit below 1 or above 15000 fails. Similarly, attempting to configure the limit below the number of neighbors currently configured fails. For example, if there are 3250 neighbors configured, you cannot set the limit below 3250.

Task ID

Task ID

Operations

bgp

write

Examples

The following example shows how to change the default maximum neighbor limit and set it to 1200:

RP/0/RSP0/CPU0:router(config)#router bgp 65530 
RP/0/RSP0/CPU0:router(config-bgp)# bgp maximum neighbor 1200

bgp redistribute-internal

To allow the redistribution of internal Border Gateway Protocol (iBGP) routes into an Interior Gateway Protocol (IGP), such as Intermediate System-to-Intermediate System (IS-IS) or Open Shortest Path First (OSPF), use the bgp redistribute-internal command in an appropriate configuration mode. To disable the redistribution of iBGP routes into IGPs, use the no form of this command.

bgp redistribute-internal

no bgp redistribute-internal

Syntax Description

This command has no keywords or arguments.

Command Default

By default, iBGP routes are not redistributed into IGPs.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use of the bgp redistribute-internal command requires the clear route * command to be issued to reinstall all BGP routes into the IP routing table.


Note


Redistributing iBGP routes into IGPs may cause routing loops to form within an autonomous system. Use this command with caution.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to redistribute iBGP routes into OSPF:
RP/0/RSP0/CPU0:router(config)#router bgp 1 
RP/0/RSP0/CPU0:router(config-bgp)# bgp redistribute-internal 
RP/0/RSP0/CPU0:router(config-bgp)# exit
RP/0/RSP0/CPU0:router(config)# router ospf area1
RP/0/RSP0/CPU0:router(config-router)# redistribute bgp 1
RP/0/RSP0/CPU0:router(config-router)# end
RP/0/RSP0/CPU0:router# clear route * 

Related Commands

Command

Description

clear bgp *

Resets all BGP neighbors.

clear route *

Resets all routes.

bgp router-id

To configure a fixed router ID for a Border Gateway Protocol (BGP)-speaking router, use the bgp router-id command in an appropriate configuration mode. To disable a fixed router ID, use the no form of this command.

bgp router-id ip-address

no bgp router-id [ ip-address ]

Syntax Description

ip-address

IP Version 4 (IPv4) address to use as the router ID. Normally, this should be an IPv4 address assigned to the router.

Command Default

If no router ID is configured in BGP, BGP attempts to use the global router ID if one is configured and available. Otherwise, BGP uses the highest IP address configured on a loopback interface.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

If you do not use the bgp router-id command to configure a router ID, an IP address is not configured on any loopback interface, and no global router ID is configured, BGP neighbors remain down.

For more details on router IDs, see the Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the local router with the router ID of 192.168.70.24:

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#bgp router-id 192.168.70.24

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

bgp scan-time

To configure scanning intervals of Border Gateway Protocol (BGP)-speaking networking devices, use the bgp scan-time command in an appropriate configuration mode. To restore the scanning interval to its default value, use the no form of this command.

bgp scan-time seconds

no bgp scan-time seconds

Syntax Description

seconds

Scanning interval (in seconds) of BGP routing information. Range is 5 to 3600 seconds.

Command Default

The default scanning interval is 60 seconds.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.0.0

Support was removed for all address family configuration modes.

Usage Guidelines

Use the bgp scan-time command to change how frequently the software processes scanner tasks, such as conditional advertisement, dynamic MED changes, and periodic maintenance tasks.

Task ID

Task ID

Operations

bgp

read, write

Examples

This example shows how to set the scanning interval to 20 seconds:

RP/0/RSP0/CPU0:router(config)# router bgp 64500
RP/0/RSP0/CPU0:router(config-bgp-af)# bgp scan-time 20

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

bgp update-delay

To set the maximum initial delay for a Border Gateway Protocol (BGP)-speaking router to send the first updates, use the bgp update-delay command in an appropriate configuration mode. To restore the initial delay to its default value, use the no form of this command.

bgp update-delay seconds [always]

nobgp update-delay [ seconds ] [ always ]

Syntax Description

seconds

Delay in seconds for the router to send the first updates. Range is 0 to 3600.

always

(Optional) Specifies that the router always wait for the update delay time, even if all neighbors have finished sending their initial updates sooner.

Command Default

120 seconds

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

When BGP is started, it waits a specified period of time for its neighbors to establish peering sessions and to complete sending their initial updates. After all neighbors complete their initial updates, or after the update delay timer expires, the best path is calculated for each route, and the software starts sending advertisements out to its peers. This behavior improves convergence time. If the software were to advertise a route as soon as it learned it, it would have to readvertise the route each time it learned a new path that was preferred over all previously learned paths.

Use the bgp update-delay command to tune the maximum time the software waits after the first neighbor is established until it starts calculating best paths and sending out advertisements.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the maximum initial delay to 240 seconds:

RP/0/RSP0/CPU0:router(config)#router bgp 64530 
RP/0/RSP0/CPU0:router(config-bgp)# bgp update-delay 240

bgp write-limit

To modify the upper bounds on update message queue lengths or to enable desynchronization, use the bgp write-limit command in an appropriate configuration mode. To return the bounds to their default values and to disable desynchronization, use the no form of this command.

bgp write-limit group-limit global-limit [desynchronize]

no bgp write-limit [ group-limit global-limit ] [desynchronize]

Syntax Description

group-limit

Per-update group limit on the number of update messages the software queues. Range is 500 to 100000000. Group limit cannot be greater than the global limit.

global-limit

Global limit on the number of update messages the software queues. Range is 500 to 100000000.

desynchronize

(Optional) Enables desynchronization.

Command Default

group-limit : 50,000

global-limit : 250,000

Desynchronizationis off.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the bgp write-limit command to configure both a per-update group and a global limit on the number of messages the software queues when updating peers. Increasing these limits can result in faster Border Gateway Protocol (BGP) convergence, but also may result in higher memory use during convergence. In addition, this command can be used to enable desynchronization. Desynchronization can decrease memory use and speed up convergence for the fastest neighbors if one or more neighbors in an update group process updates significantly slower than other neighbors in the same group. However, enabling desynchronization can cause a significant degradation in overall convergence time, especially if the router is experiencing high CPU utilization. For this reason, enabling desynchronization is discouraged.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure BGP to operate with a per-update group limit of 9000 messages and a global limit of 27,000 messages:

RP/0/RSP0/CPU0:router(config)# router bgp 65000
RP/0/RSP0/CPU0:router(config-bgp)#bgp write-limit 9000 27000 

capability additional-paths receive

To advertise capability of receiving additional paths to the peer, use the capability additional-paths receive command in neighbor or neighbor-group or session-group configuration mode. To disable the capability of receiving additional paths, use the no form of this command.

capability additional-paths receive [disable]

no capability additional-paths receive

Syntax Description

disable

Disables advertising capability of receiving additional paths.

Command Default

Capability is disabled.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Use the capability additional-paths receive command to selectively enable or disable additional paths receive capability negotiation for a particular neighbor or neighbor-group or session-group. Configuring additional-paths receive command in global address-family mode is a pre-requisite for negotiating additional paths receive capability with the peer.

If you enter the capability additional-paths receive command after some BGP sessions are established, you must restart those sessions for the new configuration to take effect. Use the clear bgp command to restart sessions.

Task ID

Task ID Operation

bgp

read, write

Examples

The following example shows how to advertise capability of receiving additional paths:

RP/0/RSP0/CPU0:router(config)#router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 10.2.3.4 
RP/0/RSP0/CPU0:router(config-bgp-nbr)#capability additional-paths receive

Related Commands

Command

Description

additional-paths receive

Configures receive capability of multiple paths for a prefix to the capable peers.  

additional-paths send

Configures send capability of multiple paths for a prefix to the capable peers.  

capability additional-paths send

Advertises capability of sending additional paths to the peer.  

capability additional-paths send

To advertise capability of sending additional paths to the peer, use the capability additional-paths send command in neighbor or neighbor-group or session-group configuration mode. To disable the capability of sending additional paths, use the no form of this command.

capability additional paths send [ disable ]

no capability additional paths send

Syntax Description

disable

Disables advertise additional paths send capability

Command Default

Capability is disabled.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release Modification
Release 4.0.0

This command was introduced.

Usage Guidelines

Use the capability additional paths send command to selectively enable or disable additional paths send capability negotiation for a particular neighbor or neighbor-group or session-group. Configuring the additional-paths send command in global address-family mode is a pre-requisite for negotiating additional paths send capability with the peer.

You must restart the BGP sessions for the new configuration to take effect. Use the clear bgp command to restart sessions.

Task ID

Task ID Operation

bgp

read, write

Examples

The following example shows how to advertise capability of sending additional paths to the peer:

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.2.3.4 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# capability additional-paths send

Related Commands

Command

Description

additional-paths receive

Configures receive capability of multiple paths for a prefix to the capable peers.  

additional-paths send

Configures send capability of multiple paths for a prefix to the capable peers.  

capability additional-paths receive

Advertises additional paths receive capability.  

capability orf prefix

To advertise prefix list-based Outbound Route Filter (ORF) capability to the Border Gateway Protocol (BGP) peer, use the capability orf prefix command in an appropriate configuration mode. To remove the capability orf prefix command from the configuration file and restore the system to its default condition in which the software does not advertise the capability, use the no form of this command.

capability orf prefix { receive | send | both | none }

no capability orf prefix [ receive | send | both | none ]

Syntax Description

receive

Sets the capability to receive the ORF from a specified neighbor.

send

Sets the capability to send the ORF to a specified neighbor.

both

Sets the capability to receive and send the ORF from or to a specified neighbor.

none

Sets the capability to no for ORF receive or send from or to a specified neighbor.

Command Default

The routing device does not receive or send route prefix filter lists.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

VRF neighbor IPv4 address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

The advertisement of the prefix list ORF capability by a BGP speaker indicates whether the speaker can send prefix lists to the specified neighbor and whether it accepts prefix lists from the neighbor. The speaker sends a prefix list if it indicated the ability to send them, and if the neighbor indicated it was willing to accept them. Similarly, the neighbor sends a prefix list to the speaker if it indicated the ability to send them and the speaker indicated the willingness to accept them.


Note


The capability orf and prefix list filter specified by orf route-policy must be explicitly configured.


If the neighbor sends a prefix list and the speaker accepts it, the speaker applies the received prefix list, plus any locally configured outbound filters, to limit its outbound routing updates to the neighbor. Increased filtering prevents unwanted routing updates between neighbors and reduces resource requirements for routing update generation and processing.

Use the capability orf prefix command to set whether to advertise send and receive capabilities to the specified neighbor.


Note


Sending a receive capability can adversely affect performance, because updates sent to that neighbor cannot be replicated for any other neighbors.


If this command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the capability orf prefix command:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# route-policy orfqq 
RP/0/RSP0/CPU0:router:(config-rpl)# if orf prefix in (10.0.0.0/8 ge 20) then 
RP/0/RSP0/CPU0:router(config-rpl)# pass 
RP/0/RSP0/CPU0:router(config-rpl)# endif 
RP/0/RSP0/CPU0:router(config-rpl)# if orf prefix in (1910::16 ge 120) then 
RP/0/RSP0/CPU0:router(config-rpl)# pass 
RP/0/RSP0/CPU0:router(config-rpl)# endif 
RP/0/RSP0/CPU0:router(config-rpl)# end-policy 
RP/0/RSP0/CPU0:router(config)# router bgp 65530
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.101.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 65534
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# route-policy pass-all out 
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# capability orf prefix both
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# orf route-policy orfqq 

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

show bgp neighbors

Displays information about BGP neighbors. Use the received prefix-filter keywords to display information on the prefix list filter.

capability suppress 4-byte-as

To suppress 4-byte AS capability from being advertised to the BGP peer, use the capability suppress 4-byte-as command in the appropriate configuration mode. To remove the capability suppress 4-byte-as command from the configuration and restore the system to the default condition, in which the software advertises the capability, use the no form of this command.

capability suppress 4-byte-as [ inheritance-disable ]

no capability suppress 4-byte-as

Syntax Description

inheritance-disable

Prevents capability suppress 4-type-as being inherited from the parent.

Command Default

4-byte-as capability is advertised to the BGP peer.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

By default, the software advertises the 4-byte AS capability to BGP peers. To override this default behavior, use the capability suppress 4-byte-as command under the command modes listed in the ''Command Modes'' section. If configured under the neighbor group or session group, all neighbors using the group inherit the configuration. Use the no option to remove the command.


Caution


The BGP session resets automatically, if the 4-byte AS capability of an existing BGP session is changed by configuring capability suppress 4-byte-as or capability suppress 4-byte-as inheritance-disable .


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the capability suppress 4-byte-as command:

RP/0/RSP0/CPU0:router# show bgp nei 10.3.3.3 conf
neighbor 10.3.3.3
 remote-as 65000             [n:internal]
 description PE3             []
 update-source Loopback0     [n:internal]
 address-family ipv4 unicast [n:internal]

RP/0/RSP0/CPU0:router#show bgp nei 10.3.3.3  
BGP neighbor is 10.3.3.3
 Remote AS 65000, local AS 65000, internal link
 Description: PE3
 Remote router ID 10.3.3.3
  BGP state = Established, up for 1w0d
  Last read 00:00:17, hold time is 180, keepalive interval is 60 seconds
  Precedence: internet
  Neighbor capabilities:
    Route refresh: advertised and received
    4-byte AS: advertised and received
    Address family IPv4 Unicast: advertised and received
  Received 25962 messages, 0 notifications, 0 in queue
  Sent 25968 messages, 1 notifications, 0 in queue
  Minimum time between advertisement runs is 0 seconds

 For Address Family: IPv4 Unicast
  BGP neighbor version 1
  Update group: 0.3
  Route refresh request: received 0, sent 0
  0 accepted prefixes, 0 are bestpaths
  Prefix advertised 0, suppressed 0, withdrawn 0, maximum limit 524288
  Threshold for warning message 75%
  An EoR was received during read-only mode

  Connections established 2; dropped 1
  Last reset 1w0d, due to BGP Notification sent: hold time expired
  Time since last notification sent to neighbor: 1w0d
  Error Code: hold time expired
  Notification data sent: None

RP/0/RSP0/CPU0:router(config)#router bgp 65000
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 10.3.3.3
RP/0/RSP0/CPU0:router(config-bgp-nbr)#capability suppress 4-byte-as 
RP/0/RSP0/CPU0:router(config-bgp-nbr)#commit
RP/0/RSP0/CPU0:router(config-bgp-nbr)#end 

RP/0/RSP0/CPU0:router# show bgp nei 10.3.3.3 

BGP neighbor is 10.3.3.3
 Remote AS 65000, local AS 65000, internal link
 Description: PE3
 Remote router ID 10.3.3.3
  BGP state = Established, up for 00:00:16
  Last read 00:00:11, hold time is 180, keepalive interval is 60 seconds
  Precedence: internet
  Neighbor capabilities:
    Route refresh: advertised and received
    Address family IPv4 Unicast: advertised and received
  Capability 4-byte-as suppress is configured
  Received 25966 messages, 0 notifications, 0 in queue
  Sent 25972 messages, 1 notifications, 0 in queue
  Minimum time between advertisement runs is 0 seconds

 For Address Family: IPv4 Unicast
  BGP neighbor version 1
  Update group: 0.2
  Route refresh request: received 0, sent 0
  0 accepted prefixes, 0 are bestpaths
  Prefix advertised 0, suppressed 0, withdrawn 0, maximum limit 524288
  Threshold for warning message 75%
  An EoR was received during read-only mode

  Connections established 3; dropped 2
  Last reset 00:00:43, due to Capabilty 4-byte-as configuration changed
  Time since last notification sent to neighbor: 1w0d
  Error Code: hold time expired
  Notification data sent: None

With the inheritance-disable keyword:

RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.101.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# capability suppress 4-byte-as inheritance-disable

RP/0/RSP0/CPU0:router# show bgp neighbor 10.0.101.1 config
neighbor 10.0.101.1
 remote-as 1                 []
 address-family ipv4 unicast []

RP/0/RSP0/CPU0:router# show bgp neighbor 10.0.101.1 
BGP neighbor is 10.0.101.1
 Remote AS 1, local AS 100, external link
 Remote router ID 0.0.0.0
  BGP state = Idle
  Last read 00:00:00, hold time is 180, keepalive interval is 60 seconds
  Precedence: internet
  Received 0 messages, 0 notifications, 0 in queue
  Sent 0 messages, 0 notifications, 0 in queue
  Minimum time between advertisement runs is 30 seconds

clear bgp

To reset a group of Border Gateway Protocol (BGP) neighbors, use the clear bgp command in EXEC mode.

clear bgp [ ipv4 { unicast | labeled-unicast | all | tunnel } | ipv6 { unicast } | all { unicast | multicast | all | labeled-unicast | tunnel } | vpnv4 unicast | vrf { vrf-name | all } { ipv4 { unicast | labeled-unicast } | ipv6 unicast } ]

Syntax Description

ipv4

(Optional) Specifies IP Version 4 address prefixes.

unicast

(Optional) Specifies unicast address prefixes.

multicast

(Optional) Specifies multicast address prefixes.

labeled-unicast

(Optional) Specifies labeled unicast address prefixes.

all

(Optional) For subaddress families, specifies prefixes for all subaddress families.

tunnel

(Optional) Specifies tunnel address prefixes.

ipv6

(Optional) Specifies IP Version 6 address prefixes.

all

(Optional) For address family, specifies prefixes for all address families.

vpnv4 unicast

(Optional) Specifies VPNv4 unicast address families.

vrf

(Optional) Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

(Optional) For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

(Optional) For VRF, specifies IPv4 unicast and labeled-unicast address families.

ipv6 unicast

(Optional) For VRF, specifies IPv6 unicast address prefixes.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the clear bgp command to reset the sessions of the specified group of neighbors (hard reset); it removes the TCP connection to the neighbor, removes all routes received from the neighbor from the BGP table, and then re-establishes the session with the neighbor.

If the graceful keyword is specified, the routes from the neighbor are not removed from the BGP table immediately, but are marked as stale. After the session is re-established, any stale route that has not been received again from the neighbor is removed.

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to hard reset neighbor 10.0.0.1:
RP/0/RSP0/CPU0:router# clear bgp 10.0.0.1

Related Commands

Command

Description

clear bgp self-originated

Clears self-originated routes.

clear bgp soft

Soft resets a group of BGP neighbors.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about the TCP and BGP connections to neighbors.

clear bgp current-mode

To switch from one BGP mode to another, use the clear bgp current-mode command in EXEC configuration mode.

clear bgp current-mode

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the clear bgp current-mode command to switch from standalone to distributed mode, or from distributed to standalone mode. The show bgp process command indicates the current BGP mode.


Note


Switching from one mode to another causes all BGP sessions to go down.


Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows the show bgp process command output before and after switching from one BGP mode to another:

RP/0/RSP0/CPU0:router# show bgp process
  
  BGP Process Information
  BGP is operating in STANDALONE mode
  Autonomous System: 3
  Router ID: 10.18.18.11
  Cluster ID: 10.18.18.11
  Fast external fallover enabled
  Neighbor logging is enabled
  Enforce first AS enabled
  Default local preference: 100
  Default keepalive: 60
  Update delay: 120
  Generic scan interval: 60
  
  Address family: IPv4 Unicast
  Dampening is not enabled
  Client reflection is enabled
  Scan interval: 60
  Main Table Version: 3
  IGP notification: IGPs notified
  RIB has converged: version 0
  
  Node                Process     Nbrs Estb Rst Upd-Rcvd Upd-Sent Nfn-Rcv Nfn-Snt
  node0_0_CPU0        Speaker        5    5  51        0        7       0       5
  
  RP/0/RSP0/CPU0:router# configure 
  RP/0/RSP0/CPU0:router(config)# router bgp 3 
  RP/0/RSP0/CPU0:router(config-bgp)# distributed speaker 1
  RP/0/RSP0/CPU0:router(config-bgp)# distributed speaker 2
  RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.101.1
  RP/0/RSP0/CPU0:router(config-bgp-nbr)# speaker-id 2 
  RP/0/RSP0/CPU0:router(config-bgp-nbr)# commit 
  RP/0/RSP0/CPU0:router# clear bgp current-mode 
  RP/0/RSP0/CPU0:router# show bgp process 
  
  BGP Process Information
  BGP is operating in DISTRIBUTED mode
  Autonomous System: 3
  Router ID: 10.18.18.11
  Cluster ID: 10.18.18.11
  Fast external fallover enabled
  Neighbor logging is enabled
  Enforce first AS enabled
  Default local preference: 100
  Default keepalive: 60
  Update delay: 120
  Generic scan interval: 60
  
  Address family: IPv4 Unicast
  Dampening is not enabled
  Client reflection is enabled
  Scan interval: 60
  Main Table Version: 1
  IGP notification: IGPs not notified
  RIB has not converged: version 0
  
  Node                Process     Nbrs Estb Rst Upd-Rcvd Upd-Sent Nfn-Rcv Nfn-Snt
  node0_0_CPU0        Speaker 1      4    1  52        0        0       0       4
  node0_0_CPU0        Speaker 2      1    0   9        0        0       0       1
  node0_0_CPU0        bRIB 1         0    0   0        0        0       0       0
  node0_0_CPU0        bRIB 2         0    0   0        0        0       0       0
  

Related Commands

Command

Description

show bgp process

Displays the current BGP process information.

clear bgp dampening

To clear Border Gateway Protocol (BGP) route dampening information and unsuppress the suppressed routes, use the clear bgp dampening command in EXEC configuration mode.

clear bgp dampening

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast and labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

ip-address

(Optional) IP address of the network about which to clear dampening information.

/mask-length

(Optional) Network mask applied to the IP address.

Command Default

If no IP address is specified, dampening information for all routes is cleared.

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Always use the clear bgp dampening command for an individual address-family. The all option for address-families with clear bgp dampening should never be used during normal functioning of the system. For example, use
clear bgp ipv4 unicast dampening prefix x.x.x./y

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear the route dampening information for all 172.20.0.0/16 IPv4 unicast paths:

RP/0/RSP0/CPU0:router# clear bgp ipv4 unicast dampening 172.20.0.0/16

Related Commands

Command

Description

bgp dampening

Enables BGP route dampening or changes various BGP route dampening factors.

show bgp dampened-paths

Displays BGP dampened routes.

clear bgp external

To clear all Border Gateway Protocol (BGP) external peers, use the clear bgp external command in EXEC configuration mode.

clear bgp external

Syntax Description

ipv4

(Optional) Specifies IP Version 4 address prefixes.

unicast

(Optional) Specifies unicast address prefixes.

multicast

(Optional) Specifies multicast address prefixes.

labeled-unicast

(Optional) Specifies labeled unicast address prefixes.

all

(Optional) For subaddress families, specifies prefixes for all subaddress families.

ipv6

(Optional) Specifies IP Version 6 address prefixes.

all

(Optional) For address family, specifies prefixes for all address families.

vpnv4 unicast

(Optional) Specifies VPNv4 unicast address families.

vrf

(Optional) Specifies VPN routing and forwarding (VRF).

vrf-name

(Optional) Name of a VRF.

all

(Optional) For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

(Optional) For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

(Optional) For VRF, specifies IPv6 unicast address families.

vpnv6 unicast

(Optional) Specifies VPNv6 unicast address families.

graceful

(Optional) Clears all external peers with a hard reset and a graceful restart. This option is available when an address family is not specified.

Command Default

No default behavior or value

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear all BGP external peers:
RP/0/RSP0/CPU0:router# clear bgp external

clear bgp flap-statistics

To clear Border Gateway Protocol (BGP) flap counts for a specified group of routes, use the clear bgp flap-statistics command in EXEC configuration mode.

clear bgp flap-statistics

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

vpnv6 unicast

Specifies VPNv6 unicast address families.

regexp regexp

(Optional) Clears flap statistics for routes whose AS paths match the regular expression.

route-policy route-policy-name

(Optional) Clears flap statistics for the specific route policy.

network

(Optional) Network for which flap counts are to be cleared.

/mask-length

(Optional) Network mask of the network for which flap counts are to be cleared.

ip-address

(Optional) Neighbor address. Clears only flap statistics for routes received from this neighbor.

Command Default

No default behavior or value

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear the flap count for all routes (in all address families) originating in autonomous system 1:
RP/0/RSP0/CPU0:router#clear bgp all all flap-statistics regexp _1$ 

The following example shows how to clear the flap count for all IPv4 unicast routes received from neighbor 172.20.1.1:
RP/0/RSP0/CPU0:router# clear bgp ipv4 unicast flap-statistics 172.20.1.1

clear bgp nexthop performance-statistics

To reset the number of received notifications and the cumulative processing time for the Border Gateway Protocol (BGP) next hop, use the clear bgp nexthop performance-statistics command in EXEC configuration mode.

clear bgp nexthop performance-statistics

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

tunnel

Specifies tunnel address prefixes.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the clear bgp nexthop performance-statistics command to reset the total number of notifications received from the Routing Information Base (RIB) and the cumulative next-hop processing time. The following information is cleared from the show bgp nexthops command output:

  • Total critical notifications received
  • Total noncritical notifications received
  • Best path deleted after last walk
  • Best path changed after last walk
  • Next-hop table total number of critical and noncritical notifications (Notf) and the time of the last notification received from the RIB (LastRIB) columns (only entries that have a status of unreachable [UR])

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear next-hop performance statistics:
RP/0/RSP0/CPU0:router# clear bgp vrf vrf_A nexthop performance statistics 

Related Commands

Command

Description

show bgp nexthops

Displays information about the BGP next-hop notifications.

clear bgp nexthop registration

To reregister a specified next hop with the Routing Information Base (RIB), use the clear bgp nexthop registration command in EXEC configuration mode.

clear bgp nexthop registration nexthop-address nexthop-address

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled-unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

tunnel

Specifies tunnel address prefixes.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

nexthop-address

Address of the next hop.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the clear bgp nexthop registration command to perform an asynchronous registration of the next hop with the RIB. The show bgp nexthops command output shows a critical notification as the LastRIBEvent for the next hop when the clear bgp nexthop registration command is used.

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to reregister the next hop with the RIB:
RP/0/RSP0/CPU0:router# clear bgp nexthop registration 10.1.1.1 

Related Commands

Command

Description

show bgp nexthops

Displays information about the BGP next-hop notifications.

clear bgp peer-drops

To clear the connection-dropped counter, use the clear bgp peer-drops command in EXEC configuration mode.

clear bgp peer-drops { * | ip-address }

Syntax Description

*

Specifies all BGP neighbors.

ip-address

IP address of a specific network neighbor.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear the connection-dropped counter for all BGP neighbors:
RP/0/RSP0/CPU0:router# clear bgp peer-drops *

Related Commands

Command

Description

show bgp neighbors

Displays information about BGP connections to neighbors.

clear bgp performance-statistics

To clear the performance statistics for all address families, use the clear bgp performance-statistics command.

clear bgp [ vrf { vrf-name | all } ] performance-statistics

Syntax Description

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear the performance statistics for all address families:
RP/0/RSP0/CPU0:router# clear bgp performance-statistics

clear bgp self-originated

To clear Border Gateway Protocol (BGP) routes that are self-originated, use the clear bgp self-originated command in EXEC configuration mode.

clear bgp { ipv4 { unicast | | multicast | | labeled-unicast | | all } | | ipv6 { unicast | | multicast | | labeled-unicast | | all | } | | all { unicast | | multicast | | labeled-unicast | | all } | | vpnv4 unicast | | vrf { vrf-name | | all } | | vpnv6 unicast } self-originated

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Self-originated routes are routes locally originated by the network command, redistribute command, or aggregate-address command.

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear self-originated IPv4 routes:

RP/0/RSP0/CPU0:router# clear bgp ipv4 unicast self-originated

Related Commands

Command

Description

aggregate-address

Creates an aggregate entry in a BGP routing table.

network (BGP)

Specifies a local network that the BGP routing process should originate and advertise to its neighbors.

redistribute (BGP)

Redistributes routes from another routing protocol into BGP.

clear bgp shutdown

To clear all Border Gateway Protocol (BGP) neighbors that shut down due to low memory, use the clear bgp shutdown command in EXEC configuration mode.

clear bgp { ipv4 { unicast | | multicast | | labeled-unicast | | all } | | ipv6 { unicast | | multicast | | labeled-unicast | | all | } | | all { unicast | | multicast | | labeled-unicast | | all } | | vpnv4 unicast | | vrf { vrf-name | | all } | | vpnv6 unicast } shutdown

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

Command Default

No default behavior or values

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to clear all shut-down BGP neighbors:

RP/0/RSP0/CPU0:router# clear bgp shutdown

Related Commands

Command

Description

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about the TCP and BGP connections to neighbors.

clear bgp soft

To soft reset a group of Border Gateway Protocol (BGP) neighbors, use the clear bgp soft command in EXEC configuration mode.

clear bgp { ipv4 { unicast | | multicast | | labeled-unicast | | all | | tunnel | | mdt } | | ipv6 { unicast | | multicast | | labeled-unicast | | all | } | | all { unicast | | multicast | | labeled-unicast | | all | | tunnel | | mdt } | | vpnv4 unicast | | vrf { vrf-name | | all } | | vpnv6 unicast } { * | | ip-address | | as | as-number | | external } soft [ [ in | { prefix-filter } | | out ] ]

Syntax Description

ipv4

Specifies IP Version 4 address prefixes.

unicast

Specifies unicast address prefixes.

multicast

Specifies multicast address prefixes.

labeled-unicast

Specifies labeled unicast address prefixes.

all

For subaddress families, specifies prefixes for all subaddress families.

tunnel

Specifies tunnel address prefixes.

ipv6

Specifies IP Version 6 address prefixes.

all

For address family, specifies prefixes for all address families.

vpnv4 unicast

Specifies VPNv4 unicast address families.

vrf

Specifies VPN routing and forwarding (VRF).

vrf-name

Name of a VRF.

all

For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

For VRF, specifies IPv6 unicast address families.

*

Soft resets all BGP neighbors.

ip-address

IP address of the neighbor to be reset.

as as-number

Autonomous system (AS) number for all neighbors to be reset. Range for 2-byte numbers is 1 to 65535. Range for 4-byte numbers is 1.0 to 65535.65535.

external

Specifies clearing of all external peers.

in

(Optional) Triggers an inbound soft reset. If the in or out keyword is not specified, both inbound and outbound soft resets are triggered.

prefix-filter

(Optional) Specifies to send a new Outbound Route Filter (ORF) to the neighbor. Neighbor installs the new ORF and resends its routes.

out

(Optional) Triggers an outbound soft reset. If the in or out keyword is not specified, both inbound and outbound soft resets are triggered.

Command Default

No default behavior or value

Command Modes

EXEC configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the clear bgp soft command to trigger a soft reset of the specified address families for the specified group of neighbors. This command is useful if you change the inbound or outbound policy for the neighbors, or any other configuration that affects the sending or receiving of routing updates.

If an outbound soft reset is triggered, BGP resends all routes for the address family to the given neighbors.

If an inbound soft reset is triggered, BGP by default sends a REFRESH request to the neighbor, if the neighbor has advertised the ROUTE_REFRESH capability. To determine whether the neighbor has advertised the ROUTE_REFRESH capability, use the show bgp neighbors command, and look for the following line of output:

  Received route refresh capability from peer.
  
  

If the neighbor does not support route refresh, but the soft-reconfiguration inbound command is configured for the neighbor, then BGP uses the routes cached as a result of the soft-reconfiguration inbound command to perform the soft reset.

If you want BGP to use the cached routes even if the neighbor supports route refresh, you can use the always keyword when configuring the soft-reconfiguration inbound command.

If the neighbor does not support route refresh and the soft-reconfiguration inbound command is not configured, then inbound soft reset is not possible. In this case, an error is printed.


Note


By default, if the configuration for an inbound or outbound route policy is changed, BGP performs an automatic soft reset. Use the bgp auto-policy-soft-reset disable command to disable this behavior.


Task ID

Task ID

Operations

bgp

execute

Examples

The following example shows how to trigger an inbound soft clear for IPv4 unicast routes received from neighbor 10.0.0.1:

RP/0/RP0/CPU0:router# clear bgp ipv4 unicast 10.0.0.1 soft in

Related Commands

Command

Description

bgp auto-policy-soft-reset disable

Disables an automatic soft reset of BGP peers when the configured inbound route policy is modified.

clear bgp

Resets a group of BGP neighbors.

clear bgp self-originated

Clears self-originated routes.

show bgp

Displays entries in the BGP routing table.

show bgp neighbors

Displays information about the TCP and BGP connections to neighbors.

soft-reconfiguration inbound

Configures the software to store updates received from a neighbor.

default-information originate (BGP)

To allow origination of a default route to be redistributed into the Border Gateway Protocol (BGP) from another protocol, use the default-information originate command in an appropriate configuration mode. To disable this function, use the no form of this command.

default-information originate

no default-information originate

Syntax Description

This command has no arguments or keywords.

Command Default

BGP does not permit redistribution of a default route into BGP.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the redistribute command to redistribute routes from another protocol into BGP. By default, if these routes include the default route (0.0.0.0/0 for IPv4 or ::/0 for IPv6), the default route is ignored. Use the default-information originate command to change this behavior so that the default route is not ignored and is redistributed into BGP along with the other routes for the protocol being redistributed.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure BGP to redistribute the default route into BGP:

RP/0/RSP0/CPU0:router(config)#router bgp 164 
RP/0/RSP0/CPU0:router(config-bgp)# default-information originate

Related Commands

Command

Description

redistribute (BGP)

Redistributes routes from another protocol into BGP.

default-metric (BGP)

To set default metric values for the Border Gateway Protocol (BGP), use the default-metric command in an appropriate configuration mode. To disable metric values, use the no form of this command.

default-metric value

no default-metric [ value ]

Syntax Description

value

Default metric value appropriate for the specified routing protocol. Range is 1 to 4294967295.

Command Default

A metric is not set.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the default-metric command to set the Multi Exit Discriminator (MED) to advertise to peers for routes that do not already have a metric set (routes that were received with no MED attribute).

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the BGP default metric:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# default-metric 10

default-originate

To cause a Border Gateway Protocol (BGP) speaker (the local router) to send the default route 0.0.0.0/0 to a neighbor for use as a default route, use the default-originate command in an appropriate configuration mode. To disable this function, use the no form of this command.

default-originate [ inheritance-disable | route-policy route-policy-name ]

no default-originate [ inheritance-disable | route-policy route-policy-name ]

Syntax Description

inheritance-disable

(Optional) Prevents the default-originate command characteristics from being inherited from a parent group.

route-policy route-policy-name

(Optional) Specifies the name of a route policy. The route policy allows route 0.0.0.0 to be injected conditionally. IPv6 address family is supported.

Command Default

The default route is not advertised to BGP neighbors.

Command Modes

IPv4 neighbor address family configuration

IPv6 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

IPv4 address family group configuration

IPv6 address family group configuration

VRF IPv4 neighbor address family configuration

VRF IPv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

The default-originate command does not require the presence of the default route (0.0.0.0/0 for IPv4 or ::/0 for IPv6) in the local router. When the default-originate command is used with a route policy, the default route is advertised if any route in the BGP table matches the policy.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to unconditionally advertise the route 0.0.0.0/0 to the neighbor 172.20.2.3:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.2.3 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 200
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# default-originate

The following example shows how to advertise the route 0.0.0.0/0 to the neighbor 172.20.2.3 only if a route exists in the BGP table that matches the route policy called default-default-policy:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.2.3
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 200
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# default-originate route-policy default-default-policy

Related Commands

Command

Description

default-information originate (BGP)

Allows the default route to be redistributed into BGP from another routing protocol.

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

description (BGP)

To annotate a neighbor, neighbor group, VPN routing and forwarding (VRF) neighbor, or session group, use the description command in an appropriate configuration mode. To remove the annotation, use the no form of this command.

description text

no description [ text ]

Syntax Description

text

Meaningful description or comment. Maximum of 80 characters.

Command Default

No comment or description exists.

Command Modes

Neighbor group configuration

Neighbor configuration

Session group configuration

VRF neighbor configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the description command to provide a description of a neighbor, neighbor group, VRF neighbor, or session group. The description is used to save user comments and does not affect software function.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the description “Our best customer” on the neighbor 192.168.13.4:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)#router bgp 65000 
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 192.168.13.4  
RP/0/RSP0/CPU0:router(config-bgp-nbr)#description Our best customer

distance bgp

To allow the use of external, internal, and local administrative distances that could be used to prefer one class of routes over another, use the distance bgp command in an appropriate configuration mode. To disable the use of administrative distances, use the nono form of this command.

distance bgp external-distance internal-distance local-distance

no distance bgp [ external-distance internal-distance local-distance ]

Syntax Description

external-distance

Administrative distance for Border Gateway Protocol (BGP) external routes. External routes are routes for which the best path is learned from a neighbor external to the autonomous system. Range is 1 to 255. Routes with a distance of 255 are not installed in the routing table.

internal-distance

Administrative distance for BGP internal routes. Internal routes are those routes that are learned from another BGP entity within the same autonomous system. Range is 1 to 255. Routes with a distance of 255 are not installed in the routing table.

local-distance

Administrative distance for BGP local routes. The local-distance argument applies to locally generated aggregate routes (such as the routes generated by the aggregate-address command) and backdoor routes installed in the routing table. Range is 1 to 255. Routes with a distance of 255 are not installed in the routing table.

Command Default

external-distance : 20

internal-distance : 200

local-distance : 200

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the distance bgp command if another protocol is known to be able to provide a better route to a node than was actually learned using external BGP, or if some internal routes should be preferred by BGP.


Note


Changing the administrative distance of BGP internal routes is considered risky and is not recommended. One problem that can arise is the accumulation of routing table inconsistencies, which can interfere with routing.


An administrative distance is a rating of the trustworthiness of a routing information source. Numerically, an administrative distance is an integer from 1 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows that iBGP routes are preferable to locally generated routes, so the administrative distance values are set accordingly:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)#distance bgp 20 20 200 

Related Commands

Command

Description

distance (IS-IS)

Defines the administrative distance assigned to routes discovered by the IS-IS protocol.

distance (OSPF)

Defines OSPF route administrative distances based on route type.

distributed speaker

To enable a distributed speaker process, use the distributed speaker command in router configuration mode. To remove the distributed speaker process, use the no form of this command.

distributed speaker id

no distributed speaker id

Syntax Description

id

ID of the distributed speaker process. Range is 1 to 15.

Command Default

Default is 0.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

If BGP is currently running in standalone mode, you must enter the clear bgp current-mode command to switch from standalone or distributed mode.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable distributed speaker process 3:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# distributed speaker 3

Related Commands

Command

Description

clear bgp current-mode

Switch BGP from one mode to another

dscp (BGP)

To set the differentiated services code point (DSCP) value, use the dscp command in the appropriate configuration mode. To remove the dscp command from the configuration file and restore the system to its default interval values, use the no form of this command.

dscp value

no dscp [ value ]

Syntax Description

value

Value of the DSCP. The DSCP value can be a number from 0 to 63, or it can be one of the following keywords: default , ef , af11 , af12 , af13 , af21 , af22 , af23 , af31 , af32 , af33 , af41 , af42 , af43 , cs1 , cs2 , cs3 , cs4 , cs5 , cs6 , or cs7 .

Command Default

No default behavior or values

Command Modes

Neighbor configuration

Neighbor session group configuration

Neighbor group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the dscp command to change the minimum and maximum packet thresholds for the DSCP value.

Table 1 lists the DSCP default settings used by the dscp command. The DSCP value, corresponding minimum threshold, maximum threshold, and mark probability are listed. The last row of the table (the row labeled "default") shows the default settings used for any DSCP value not specifically shown in the table.

Table 2 dscp Default Settings

DSCP (Precedence)

Minimum Threshold

Maximum Threshold

Mark Probability

af11

32

40

1/10

af12

28

40

1/10

af13

24

40

1/10

af21

32

40

1/10

af22

28

40

1/10

af23

24

40

1/10

af31

32

40

1/10

af32

28

40

1/10

af33

24

40

1/10

af41

32

40

1/10

af42

28

40

1/10

af43

24

40

1/10

cs1

22

40

1/10

cs1

24

40

1/10

cs3

26

40

1/10

cs4

28

40

1/10

cs5

30

40

1/10

cs6

32

40

1/10

cs7

34

40

1/10

ef

36

40

1/10

default

20

40

1/10

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the DSCP value to af32:

RP/0/RSP0/CPU0:router(config)# router bgp 5
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 10.1.1.1  
RP/0/RSP0/CPU0:router(config-bgp-nbr)#remote-as 100 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# dscp af32 

ebgp-multihop

To accept and attempt Border Gateway Protocol (BGP) connections to external peers residing on networks that are not directly connected, use the ebgp-multihop command in an appropriate configuration mode. To disable connections to external peers and allow only direct connections between neighbors, use the no form of this command.

ebgp-multihop [ ttl-value ] [ mpls ]

no ebgp-multihop [ ttl-value ] [ mpls ]

Syntax Description

ttl-value

(Optional) Time-to-live (TTL) value. Range is 1 to 255 hops.

mpls

(Optional) Disables BGP label rewrite.

Command Default

Default TTL value is 255.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.0.0

The mpls keyword was supported.

Usage Guidelines

Use the ebgp-multihop command to enable multihop peerings with external BGP neighbors. The BGP protocol states that external neighbors must be directly connected (one hop away). The software enforces this by default; however, the ebgp-multihop command can be used to override this behavior.

Use of the mpls option in the ebgp-multihop command prevents BGP from enabling MPLS on the peering interface and also prevents allocation of Implicit-NULL rewrite labels for nexthop addresses learned from the peer. This is useful in some scenarios in which MPLS forwarding labels to the nexthops have already been learned via BGP labeled-unicast or LDP.

If this command is configured for a neighbor group or session group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to allow a BGP connection to neighbor 172.20.16.6 of up to 255 hops away:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.16.6
RP/0/RSP0/CPU0:router(config-bgp-nbr)# ebgp-multihop

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

session-group

Creates a session group and enters session group configuration mode.

export route-policy

To configure an export route policy, use the export route-policy command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

export route-policy policy-name

no export route-policy [ policy-name ]

Syntax Description

policy-name

Name of the configured route policy.

Command Default

No default behavior or values

Command Modes

Global VRF IPv4 address family configuration

Global VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the export route-policy command to define the conditions that allow specified routes to be tagged with specified route-targets.

Task ID

Task ID

Operations

bgp

read, write

ip-services

read, write

Examples

The following example shows how to configure an export route policy:

RP/0/RSP0/CPU0:router(config)# vrf vrf-1
RP/0/RSP0/CPU0:router(config-vrf)#address-family ipv4 unicast  
RP/0/RSP0/CPU0:router(config-vrf-af)# export route-policy policy-A

Related Commands

Command

Description

import route-policy

Specifies a route policy to import routes into the VRF instance.

export route-target

To configure a VPN routing and forwarding (VRF) export route-target extended community, use the export route-target command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

export route-target [ as-number:nn | | ip-address:nn ]

no export route-target [ as-number:nn | | ip-address:nn ]

Syntax Description

as-number:nn

(Optional) as-number —Autonomous system (AS) number of the route-target extended community.

  • as-number
    • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
    • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
    • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.
  • nn —32-bit number

ip-address:nn

(Optional) IP address of the route-target extended community.

  • ip-address —32-bit IP address
  • nn —16-bit number

Command Default

No default behavior or values

Command Modes

Global VRF IPv4 address family configuration

Global VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

Export route-target extended communities are associated with prefixes when advertised to remote provider edge (PE) routers. The remote PE routers import the route-target extended communities into a VRF instance that has the import route-targets that match the exported route-target extended communities.

To specify multiple route targets, enter export route target configuration mode then enter one route target for each command line.

Task ID

Task ID

Operations

bgp

read, write

ip-services

read, write

Examples

The following example shows how to specify an export route-target:

RP/0/RSP0/CPU0:router(config)# vrf vrf-1
RP/0/RSP0/CPU0:router(config-vrf)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-vrf-af)# export route-target 500:1 

Related Commands

Command

Description

import route-target

Specifies the import route-target.

import route-policy

To configure an import route policy, use the import route-policy command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

import route-policy policy-name

no import route-policy [ policy-name ]

Syntax Description

policy-name

Name of the configured route policy.

Command Default

No default behavior or values

Command Modes

Global VRF IPv4 address family configuration

Global VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the import route-policy command to define the conditions that allow specified routes to be imported into the VPN routing and forwarding (VRF) instance if the routes are tagged with specified route-targets.

Task ID

Task ID

Operations

bgp

read, write

ip-services

read, write

Examples

The following example shows how to allow only policy-B to be imported to VRF:
RP/0/RSP0/CPU0:router(config)# vrf vrf-1
RP/0/RSP0/CPU0:router(config-vrf)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-vrf-af)# import route-policy policy-B

Related Commands

Command

Description

export route-policy

Specifies a route policy to export routes from the VRF instance.

import route-target

To configure a VPN routing and forwarding (VRF) import route-target extended community, use the import route-target command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

import route-target [ as-number:nn | | ip-address:nn ]

no import route-target [ as-number:nn | | ip-address:nn ]

Syntax Description

as-number:nn

(Optional) Autonomous system (AS) number of the route-target extended community.

  • as-number
    • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
    • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
    • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.
  • nn —32-bit number

ip-address:nn

(Optional) IP address of the route-target extended community.

  • ip-address —32-bit IP address
  • nn —16-bit number

Command Default

No default behavior or values

Command Modes

Global VRF IPv4 address family configuration

Global VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

Use the import route-target command to specify that prefixes associated with the configured import route-target extended communities are imported into the VRF instance.

To specify multiple route targets, enter import route target configuration mode, then enter one route target for each command line.

Task ID

Task ID

Operations

bgp

read, write

ip-services

read, write

Examples

The following example shows how to specify an import route-target:

RP/0/RSP0/CPU0:router(config)#vrf vrf-1 
RP/0/RSP0/CPU0:router(config-vrf)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-vrf-af)# import route-target 500:99

Related Commands

Command

Description

export route-target

Specifies the export route-target.

ignore-connected-check

To enable the software to bypass the directly connected next hop check for single-hop eBGP peering, use the ignore-connected-check command in an appropriate configuration mode. To re-enable the directly connected next hop check, use the no form of this command.

ignore-connected-check [ inheritance-disable ]

no ignore-connected-check

Syntax Description

inheritance-disable

Prevents the ignore-connected-check command from being inherited from the parent.

Command Default

Ability to bypass the directly connected next hop check is disabled.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable ignore-connected check configuration for neighbor 10.2.3.4:

RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.2.3.4
RP/0/RSP0/CPU0:router(config-bgp-nbr)# ignore-connected-check

keychain

To apply key chain-based authentication on a TCP connection between two Border Gateway Protocol (BGP) neighbors, use the keychain command in an appropriate configuration mode. To disable key chain authentication, use the no form of this command.

keychain name

no keychain [ name ]

Syntax Description

name

Key chain name configured using the keychain command. The name must be a maximum of 32 alphanumeric characters.

Command Default

When this command is not specified in the appropriate configuration mode, key chain authentication is not enabled on a TCP connection between two BGP neighbors.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Specify a key chain to enable key chain authentication between two BGP peers. Use the keychain command to implement hitless key rollover for authentication.

If this command is configured for a neighbor group or a session group, a neighbor using the group inherits the configuration. Values of commands configured specifically for a neighbor override inherited values.

Note


BGP only supports HMAC-MD5 and HMAC-SHA1-12 cryptographic algorithms.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure neighbor 172.20.1.1 to use the key chain authentication configured in the keychain_A key chain:
RP/0/RSP0/CPU0:router(config)# router bgp 140 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# keychain keychain_A  

Related Commands

Command

Description

keychain-disable

Overrides any inherited keychain configuration from a neighbor group or session group for BGP neighbors.

keychain-disable


Note


Effective with Release 3.9.0, the keychain-disable command was replaced by the keychain inheritance-disable command. See the keychain inheritance-disable command for more information.

To override any inherited key chain configuration from a neighbor group or session group for Border Gateway Protocol (BGP) neighbors, use the keychain-disable command in an appropriate configuration mode. To disable overriding any inherited key chain command, use the no form of this command.

keychain-disable

no keychain-disable

Syntax Description

This command has no arguments or keywords.

Command Default

Configured key chains for neighbor and session groups are inherited.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

This command was replaced by the keychain inheritance-disable command.

Usage Guidelines

If you specify a key chain on a neighbor group or session group, all users of the group inherit the key chain. Specifying a different keychain command specifically on a neighbor that uses the group overrides the inherited value. Specifying keychain-disable on a neighbor that uses the group disables key chain authentication for the neighbor.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable key chain authentication for neighbor 172.20.1.1, preventing it from inheriting the key chain keychain_A from session group group1:

RP/0/RSP0/CPU0:router(config)# router bgp 140 
RP/0/RSP0/CPU0:router(config-bgp)# session-group group1 
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# keychain keychain_A 
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# exit 
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 172.20.1.1  
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 2 
RP/0/RSP0/CPU0:router(config-bgp-nbr)#use session-group group1  
RP/0/RSP0/CPU0:router(config-bgp-nbr)# keychain-disable 

Related Commands

Command

Description

keychain

Enables key chain authentication on a TCP connection between two BGP neighbors.

keychain inheritance-disable

To override any inherited key chain configuration from a neighbor group or session group for Border Gateway Protocol (BGP) neighbors, use the keychain inheritance-disable command in an appropriate configuration mode. To disable overriding any inherited key chain command, use the no form of this command.

keychain inheritance-disable

no keychain inheritance-disable

Syntax Description

This command has no arguments or keywords.

Command Default

Configured key chains for neighbor and session groups are inherited.

Command Modes

Neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

If you specify a key chain on a neighbor group or session group, all users of the group inherit the key chain. Specifying a different keychain command specifically on a neighbor that uses the group overrides the inherited value. Specifying keychain inheritance-disable on a neighbor that uses the group disables key chain authentication for the neighbor.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable key chain authentication for neighbor 172.20.1.1, preventing it from inheriting the key chain keychain_A from session group group1:
RP/0/RSP0/CPU0:router(config)#router bgp 140 
RP/0/RSP0/CPU0:router(config-bgp)# session-group group1 
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# keychain keychain_A 
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# exit 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 2 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use session-group group1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# keychain inheritance-disable 

Related Commands

Command

Description

keychain

Enables key chain authentication on a TCP connection between two BGP neighbors.

label-allocation-mode

To set the MPLS/VPN label allocation mode, use the label-allocation-mode command in VRF configuration mode. To remove the label-allocation-mode command from the configuration file and restore the system to its default condition, use the no form of this command.

label-allocation-mode [ per-ce | ]

no label-allocation-mode

Syntax Description

per-ce

Specifies that the same label is used for all the routes advertised from a unique customer edge (CE) peer or router.

Command Default

Per-prefix is the default label allocation mode.

Command Modes

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Each prefix that belongs to a VRF instance is advertised with a single label, causing an additional lookup to be performed in the VRF forwarding table to determine the customer edge (CE) next hop for the packet. Use the label-allocation-mode command with the per-ce keyword to avoid the additional lookup on the PE router and conserve label space. This mode allows the PE router to allocate one label for every immediate next hop. The label is directly mapped to the next hop so there is no VRF route lookup performed during data forwarding. However, the number of labels allocated is one for each CE rather than one for each prefix.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the label allocation mode to customer edge:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# vrf vrf-1
RP/0/RSP0/CPU0:router(config-bgp-vrf)# label-allocation-mode per-ce 

local-as

To allow customization of the autonomous system number for external Border Gateway Protocol (eBGP) neighbor peerings, use the local-as command in an appropriate configuration mode. To disable customization of local autonomous system values for eBGP neighbor peerings, use the no form of this command.

local-as { as-number [ no-prepend [ replace-as [dual-as] ] ] | inheritance-disable }

no local-as [ as-number [ no-prepend [ replace-as [dual-as] ] ] | inheritance-disable ]

Syntax Description

as-number

Valid autonomous system number.

Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.

Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.

Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.

Cannot be the autonomous system number to which the neighbor belongs.

no-prepend

(Optional) Specifies that local autonomous system values are not prepended to announcements from the neighbor.

replace-as

(Optional) Specifies that prepend only local autonomous system values to announcements to the neighbor.

dual-as

(Optional) Dual-AS mode.

inheritance-disable

Prevents local AS from being inherited from the parent.

Command Default

The BGP autonomous system number specified in the router bgp command is used, except when confederations are in use. The confederation autonomous system is used for external neighbors in an autonomous system that is not part of the confederation.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported. The dual-as keyword was added. The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

You can specify the autonomous system number the local BGP uses to peer with each neighbor. The autonomous system number specified with this command cannot be the local BGP autonomous system number (specified with the router bgp command) or the autonomous system number of the neighbor (specified with the remote-as command). This command cannot be specified for internal neighbors or for external neighbors in an autonomous system that is part of a confederation.

If this command is configured for a neighbor group or session group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows BGP using autonomous system 30 for the purpose of peering with neighbor 172.20.1.1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 300
RP/0/RSP0/CPU0:router(config-bgp-nbr)# local-as 30

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

session-group

Creates a session group and enters session group configuration mode.

maximum-paths (BGP)

To control the maximum number of parallel routes that Border Gateway Protocol (BGP) installs in the routing table, use the maximum-paths command in an appropriate configuration mode. To set the maximum number of parallel routes the software installs to the default value, use the no form of this command.

maximum-paths { ebgp | ibgp | eibgp } maximum [ unequal-cost ]

no maximum-paths { ebgp | ibgp | eibgp } [ maximum ] [ unequal-cost ]

Syntax Description

ebgp

Specifies external BGP multipath peers.

ibgp

Specifies internal BGP multipath peers.

eibgp

Specifies internal and external BGP multipath peers. eiBGP allows simultaneous use of internal and external paths.

maximum

Maximum number of parallel routes that BGP installs in the routing table. Range is 2 to 8

unequal-cost

(Optional) Allows iBGP multipaths to have different BGP next-hop Interior Gateway Protocol (IGP) metrics. This option is available when the ibgp keyword is used.

Command Default

One path is installed in the routing table.

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the maximum-paths command to allow the BGP protocol to install multiple paths into the routing table for each prefix. Multiple paths are installed for external peers that are from the same autonomous system and are equal cost (according to the BGP best-path algorithm). Similarly, multiple paths are installed for internal peers that are equal cost based on the BGP best-path algorithm. The IGP metric to the BGP next hop is the same as the best-path IGP metric unless the router is configured for unequal cost iBGP multipath or eiBGP multipath. See Implementing BGP in the Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide for information on the BGP best-path algorithm.


Note


The maximum-paths command with the eibgp keyword cannot be configured if the ibgp or ebgp keywords have been configured, because the eibgp keyword is a superset of the ibgp or ebgp keywords.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to allow a maximum of four paths to a destination installed into the IPv4 unicast routing table:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# maximum-paths ebgp 4

maximum-prefix (BGP)

To control how many prefixes can be received from a neighbor, use the maximum-prefix command in an appropriate configuration mode. To set the prefix limits to the default values, use the no form of this command.

maximum-prefix maximum [ threshold ] [ warning-only ] [ restart time-interval ]

no maximum-prefix maximum [ threshold ] [ warning-only ] [ restart time-interval ]

Syntax Description

maximum

Maximum number of prefixes allowed from this neighbor. Range is 1 to 4294967295.
Note   

When using additional-paths feature, each path with a unique path ID received from a peer is counted separately for the purpose of maximum-prefix functionality. Hence, the maximum value should be configured appropriately when the peer is capable of sending additional-paths.

threshold

(Optional) Integer specifying at what percentage of the maximum argument value the software starts to generate a warning message. Range is 1 to 100.

warning-only

(Optional) Instructs the software to generate a log message only when the maximum argument value is exceeded, and not terminate the peering.

restart time-interval

(Optional) Sets the time interval (in minutes) after which peering session should be reestablished.

Configure restart time interval in minutes. Range is 1 to 65535.

Command Default

When this command is not specified, the following defaults apply:

  • IPv4 multicast: 131,072 prefixes
  • IPv4 tunnel: 524, 288 prefixes
  • IPv4 unicast: 524,288 prefixes
  • IPv6 unicast: 131,072 prefixes
  • VPNv4 unicast: 524,288 prefixes
  • IPv4 Unicast: 1048576
  • IPv4 Labeled-unicast: 131072
  • IPv6 Unicast: 524288
  • IPv6 Labeled-unicast: 131072
  • IPv4 Tunnel: 1048576
  • IPv4 Multicast: 131072
  • IPv6 Multicast: 131072
  • VPNv4 Unicast: 2097152
  • IPv4 MDT: 131072
  • VPNv6 Unicast: 1048576
  • L2VPN EVPN: 2097152

The default threshold when a warning message is generated is 75 percent.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv6 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

IPv4 tunnel neighbor address family configuration

IPv4 tunnel neighbor group address family configuration

IPv4 tunnel address family group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the maximum-prefix command to configure a maximum number of prefixes that a BGP router is allowed to receive from a neighbor. It adds another mechanism (besides routing policy) to control prefixes received from a peer.

When the number of received prefixes exceeds the maximum number configured, the software terminates the peering, by default, after sending a cease notification to the neighbor. However, if the warning-only keyword is configured, the software writes only a log message, but continues peering with the sender. If the peer is terminated, the peer stays down until the clear bgp command is issued or the restart time-interval option is used.

This command takes effect immediately if configured on an established neighbor unless the number of prefixes received from the neighbor already exceeds the configured limits.

If this command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

This example shows the maximum number of IP Version 4 (IPv4) unicast prefixes allowed from the neighbor 192.168.40.24 set to 1000:
RP/0/RSP0/CPU0:router(config-bgp)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 192.168.40.24
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)#address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# maximum-prefix 1000

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

clear bgp

Resets a BGP connection using BGP hard or soft reconfiguration.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

mpls activate (BGP)

To enable Multiprotocol Label Switching (MPLS) on an interface basis for ASBR and CSC configurations whenever a bgp confederation configuration is used, use the mpls activate command in bgp configuration mode. This is needed for InterAS (option B and C) and Carrier Supporting Carrier (CSC) configurations with confederations.

The normal InterAS and CSC configurations (without confederations) do not need to enable this.

To restore the system to its default condition, use the no form of this command.

mpls activate interface id

no mpls activate interface id

Syntax Description

interface id

Name of the interface.

Command Default

No default behavior or values

Command Modes

Router configuration

Neighbor configuration

IPv4 address family group configuration

VPNv4 address family group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Thempls activate command enables MPLS on the interface specified and also adds the implicit null rewrite corresponding to the peer associated with the interface. The interface specified must be the one corresponding to the inter-AS ASBR or CSC peer.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to activate MPLS for InterAS Option B (with confederations):

RP/0/RSP0/CPU0:router(config)#router bgp 1 
  
            
  bgp confederation peers
  
     2002
  
    !
  
    bgp confederation identifier 4589
  
    bgp router-id 3.3.3.3
  
    mpls activate
  
     interface GigabitEthernet0/1/0/0
  
    !
  
    address-family ipv4 unicast
  
     redistribute connected
  
    !
  
    address-family vpnv4 unicast
  
     retain route-target all
  
    !
  
    neighbor 10.0.0.9
  
     remote-as 2002
  
     address-family ipv4 unicast
  
      route-policy pass in
  
      route-policy pass out
  
     !
  
     address-family vpnv4 unicast
  
      route-policy pass in
  
  

The following example shows how to activate MPLS for CSC (with confederations):

  router bgp 2002
    bgp confederation peers
     1
    !
    bgp confederation identifier 4589
    bgp router-id 4.4.4.4
    address-family ipv4 unicast
     allocate-label all
    !
    address-family vpnv4 unicast
     retain route-target all
    !
    vrf foo
     rd 1:1
     mpls activate
      interface GigabitEthernet0/1/0/2
     !
     address-family ipv4 unicast
      redistribute connected
      allocate-label all
     !
     neighbor 10.0.0.1
      remote-as 1
      address-family ipv4 unicast
      !
      address-family ipv4 labeled-unicast
       route-policy pass in
       route-policy pass out
      !
     !
    !
  !
RP/0/RSP0/CPU0:router#show mpls forwarding
  Local  Outgoing    Prefix             Outgoing Next Hop        Bytes
  Label  Label       or ID              Interface 
  Switched
  ------ ----------- ------------------ ------------ ---------------
  ------------
  16000  Aggregate   foo: Per-VRF Aggr[V]   \
                                         foo                          0
  16001  Pop         10.0.0.0/16[V]     Gi0/1/0/2    10.0.0.1        44
  
  
  
  
RP/0/RSP0/CPU0:router#show mpls interfaces
  Interface                  LDP      Tunnel   Enabled
  -------------------------- -------- -------- --------
  GigabitEthernet0/1/0/2     No       No       Yes
  
  

Related Commands

Command

Description

address-family (BGP)

Enters address family configuration mode for configuring BGP routing sessions.

neighbor (BGP)

To enter neighbor configuration mode for configuring Border Gateway Protocol (BGP) routing sessions, use the neighbor command in an appropriate configuration mode. To delete all configuration for a neighbor and terminate peering sessions with the neighbor, use the no form of this command.

neighbor ip-address

no neighbor ip-address

Syntax Description

ip-address

IPv4 or IPv6 IP address of the BGP-speaking neighbor.

Command Default

Neighbor mode is not specified.

Command Modes

Router configuration

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

From router configuration mode, you can use this command to enter neighbor configuration mode.

From neighbor configuration mode, you can enter address family configuration for the neighbor by using the address-family command, which allows you to configure routing sessions for IP Version 4 and IP Version 6 address prefixes.

The neighbor command does not cause the neighbor to be configured and does not result in a peering to be established with the neighbor. To create the neighbor, you configure a remote autonomous system number by entering the remote-as command, or the neighbor can inherit a remote autonomous system from a neighbor group or session group if the use command is applied.


Note


A neighbor must have must a remote autonomous system number, and an IP address and address family must be enabled on the neighbor.


Unlike IPv4, IPv6 must be enabled before any IPv6 neighbors can be defined. Enable IPv6 in router configuration mode using the address-family command.


Note


Configuration for the neighbor cannot occur (peering is not established) until the neighbor is given a remote as-number and neighbor address.


The no form of this command causes the peering with the neighbor to be terminated and all configuration that relates to the neighbor to be removed.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to place the router in neighbor configuration mode for BGP routing process 1 and configure the neighbor IP address 172.168.40.24 as a BGP peer:
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.168.40.24
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 65000

The following example shows how to enable IPv6 for BGP, then place the router in neighbor configuration mode for an IPv6 neighbor, 3000::1, and configure neighbor 3000::1 as a BGP peer:
RP/0/RSP0/CPU0:router(config)# router bgp 100 
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv6 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 3000::1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 2002 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv6 unicast 

Related Commands

Command

Description

address-family (BGP)

Enters address family configuration mode for configuring BGP routing sessions.

remote-as (BGP)

Adds an entry to the BGP neighbor table.

use

Inherits characteristics from a neighbor group, session group, or address family group.

neighbor-group

To create a neighbor group and enter neighbor group configuration mode, use the neighbor-group command in router configuration mode. To remove a neighbor group and delete all configuration associated with the group, use the no form of this command.

neighbor-group name

no neighbor-group name

Syntax Description

name

Neighbor group name.

Command Default

No neighbor group mode is specified.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

The neighbor-group command puts the router in neighbor group configuration mode and creates a neighbor group.

A neighbor group helps you apply the same configuration to one or more neighbors. After a neighbor group is configured, each neighbor can inherit the configuration through the use command. If a neighbor is configured to use a neighbor group, the neighbor, by default, inherits the entire configuration of the neighbor group, which includes the address family-independent and address family-specific configurations. The inherited configuration can be overridden if you directly configure commands for the neighbor or if you configure session groups or address family groups with the use command.

From neighbor group configuration mode, you can configure address family-independent parameters for the neighbor group. To enter address family-specific configuration for the neighbor group, use the address-family command when in the neighbor group configuration mode.


Note


If an address family is configured for a neighbor group, neighbors that use the neighbor group attempt to exchange routes in that address family.


The no form of this command ordinarily causes all configuration for the neighbor group to be removed. If using the no form would result in a neighbor losing its remote autonomous system number, the configuration is rejected. In this scenario, the neighbor configuration must be either removed or configured with a remote autonomous system number before the neighbor group configuration can be removed.


Note


Neighbor groups should not be configured with a mixture of IPv4 and IPv6 address families, because such a neighbor group is not usable by any neighbor. Note that within the Cisco IOS XR system configuration architecture, it is possible to create such a neighbor group; however, any attempt to use it is rejected.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to create a neighbor group called group1 that has IP Version 4 (IPv4) unicast and IPv4 multicast activated along with various configuration features. The neighbor group is used by neighbor 10.0.0.1 and neighbor 10.0.0.2, which allows them to inherit the entire group1 configuration.

RP/0/RSP0/CPU0:router(config)# router bgp 65530
RP/0/RSP0/CPU0:router(config-bgp)# neighbor-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# remote-as 65535
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# advertisement-interval 2
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# send-community-ebgp
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# exit
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# next-hop-self
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp-af)# exit
RP/0/RSP0/CPU0:router(config-bgp-nbrgrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 10.0.0.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use neighbor-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.2
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use neighbor-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# exit

Related Commands

Command

Description

address-family (BGP)

Enters various address family configuration modes for configuring BGP routing sessions.

neighbor (BGP)

Enters neighbor configuration mode for configuring BGP routing sessions.

use

Inherits characteristics from a neighbor group, a session group, or an address family group.

network (BGP)

To specify that the Border Gateway Protocol (BGP) routing process should originate and advertise a locally known network to its neighbors, use the network command in an appropriate configuration mode. To disable originating or advertising the network to neighbors, use the no form of this command.

network { ip-address/prefix-length | | ip-address mask } [ route-policy route-policy-name ]

no network { ip-address/prefix-length | | ip-address mask } [ route-policy route-policy-name ]

Syntax Description

ip- address

Network that BGP advertises.

/ prefix-length

Length of the IP address prefix. A decimal value that indicates how many of the high-order contiguous bits of the address compose the prefix (the network portion of the address). A slash (/) must precede the decimal value.

ip-address mask

Network mask applied to the ip-address argument.

route-policy route-policy-name

(Optional) Specifies a route policy to use to modify the attributes of the network.

Command Default

No networks are specified.

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

A network specified with this command is originated and advertised to neighbors only if there exists a route for the network in the routing table. That is, there must be a route learned using local or connected networks, static routing, or a dynamic IGP such as IS-IS or OSPF.

Other than the available system resources on the router, no limit exists on the number of network commands that can be configured.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the local router to originate the IPv4 unicast network 172.20.0.0/16:
RP/0/RSP0/CPU0:router(config)#router bgp 120 
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# network 172.20.0.0/16

Related Commands

Command

Description

network backdoor

Specifies a backdoor route to a BGP border router that provides better information about the network.

redistribute (BGP)

Redistributes routes from one routing domain into another routing domain.

network backdoor

To set the administrative distance on an external Border Gateway Protocol (eBGP) route to that of a locally sourced BGP route, causing it to be less preferred than an Interior Gateway Protocol (IGP) route, use the network backdoor command in an appropriate configuration mode. To disable setting the administrative distance to the value for locally sourced BGP routes, use the no form of this command.

network { ip-address/prefix-length | | ip-address mask } backdoor

no network { ip-address/prefix-length | | ip-address mask } backdoor

Syntax Description

ip-address

Network that provides a backdoor route.

/ prefix-length

Length of the IP address prefix. A decimal value that indicates how many of the high-order contiguous bits of the address compose the prefix (the network portion of the address). A slash (/) must precede the decimal value.

mask

Network mask applied to the ip-address argument.

Command Default

No backdoor routes are installed.

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VRF IPv4 address family configuration

VRF IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Configuring the network backdoor command does not cause BGP to originate a network, even if an IGP route for the network exists. Ordinarily, the backdoor network would be learned through both an eBGP and IGP. The BGP best-path selection algorithm does not change when a network is configured as a backdoor network.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows IP Version 4 (IPv4) unicast network 192.168.40.0/24 configured as a backdoor network:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# network 192.168.40.0/24 backdoor

Related Commands

Command

Description

network (BGP)

Specifies a local network that the BGP routing process should originate and advertise to its neighbors.

next-hop-self

To disable next-hop calculation and insert your own address in the next-hop field of Border Gateway Protocol (BGP) updates, use the next-hop-self command in an appropriate configuration mode. To enable next-hop calculation, use the no form of this command.

next-hop-self [ inheritance-disable ]

no next-hop-self [ inheritance-disable ]

Syntax Description

inheritance-disable

(Optional) Allows a next-hop calculation override when this feature may be inherited from a neighbor group or address family group.

Command Default

When this command is not specified, the software calculates the next hop for BGP updates accepted by the router.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

VPNv4 address family group configuration

IPv4 neighbor address family configuration

VPNv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VPNv4 neighbor group address family configuration

IPv4 labeled-unicast address family configuration

IPv6 labeled-unicast address family configuration

VRF labeled-unicast address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Release 4.0

This command was supported in the following address family configuration modes:

  • IPv4 labeled-unicast
  • IPv6 labeled-unicast
  • VRF labeled-unicast

Usage Guidelines

Use the next-hop-self command to set the BGP next-hop attribute of routes being advertised over a peering session to the local source address of the session.

This command is useful in nonmeshed networks in which BGP neighbors may not have direct access to all other neighbors on the same IP subnet.

If this command is configured for a neighbor group or address family group, a neighbor using the group inherits the configuration. Configuring the command specifically for a neighbor overrides any inherited value.

Configuring the next-hop-self command under IPv4 labeled-unicast, IPv6 labeled-unicast, or VRF labeled-unicast address family configuration mode enables next-hop-self for labeled prefixes advertised to an iBGP peer.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the next hop of the update field for all IP Version 4 (IPv4) unicast routes advertised to neighbor 172.20.1.1 to an address of the local router:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# next-hop-self

The following example shows how to disable the next-hop-self command for neighbor 172.20.1.1. If not overridden, the next hop would be inherited from address family group group1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# next-hop-self
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# use af-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# next-hop-self inheritance-disable

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

use

Inherits characteristics from a neighbor group, session group, or address family group.

next-hop-unchanged

To disable overwriting of the next hop before advertising to external Border Gateway Protocol (eBGP) peers, use the next-hop-unchanged command in an appropriate configuration mode. To enable overwriting of the next hop, use the no form of this command.

next-hop-unchanged [ inheritance-disable ]

no next-hop-unchanged [ inheritance-disable | multipath ]

Syntax Description

inheritance-disable

(Optional) Allows overwriting of the next hop before advertising to eBGP peers when this feature may be inherited from a neighbor group or address family group.

Command Default

Overwriting of the next hop is allowed.

Command Modes

VPNv4 address family group configuration

VPNv4 neighbor address family configuration

VPNv4 neighbor group address family configuration

IPv4 labeled-unicast address family configuration

IPv6 labeled-unicast address family configuration

IPv4 address family configuration

IPv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Release 4.0.0

This command was supported in the following address family configuration modes:

  • IPv4 labeled-unicast address family configuration
  • IPv6 labeled-unicast address family configuration
  • IPv4 unicast address family configuration
  • IPv6 unicast address family configuration

Usage Guidelines

Use the next-hop-unchanged command to propagate the next hop unchanged for multihop eBGP peering sessions. This command should not be configured on a route reflector, and the next-hop-self command should not be used to modify the next-hop attribute for a route reflector when this feature is enabled for a route reflector client.


Note


Incorrectly setting BGP attributes for a route reflector can cause inconsistent routing, routing loops, or a loss of connectivity. Setting BGP attributes for a route reflector should be attempted only by an experienced network operator.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable the overwriting of next hops before advertising to eBGP peers:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# next-hop-unchanged disable
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# exit

Related Commands

Command

Description

next-hop-self

Disables next-hop calculation and allows you to insert your own address in the next-hop field of BGP updates.

use

Inherits characteristics from a neighbor group, session group, or address family group.

nexthop route-policy

To specify that BGP routes are resolved using only next hops whose routes match specific characteristics, use the nexthop route-policy command in the appropriate configuration mode. To remove the nexthop route-policy command from the configuration file and restore the system to its default behavior, use the no form of this command.

nexthop route-policy route-policy-name

no nexthop route-policy route-policy-name

Syntax Description

route-policy-name

Route policy to use for filtering based on next hops.

Command Default

No default behavior or values

Command Modes

IPv4 address family configuration

IPv6 address family configuration

VPNv4 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the nexthop route-policy command to configure route policy filtering using next hops.

The BGP next-hop tracking feature allows you to specify that BGP routes are resolved using only next hops whose routes have the following characteristics:

  • To avoid the aggregate routes, the prefix length must be greater than a specified value.
  • The source protocol must be from a selected list, ensuring that BGP routes are not used to resolve next hops that could lead to oscillation.

This route policy filtering is possible because RIB identifies the source protocol of a route that resolves a next hop as well as the mask length associated with the route.

The next-hop attach point supports matching using the protocol name and mask length. BGP marks all next hops that are rejected by the route policy as invalid, and no best path is calculated for the routes that use the invalid next hop. The invalid next hops continue to stay in the active cache and can be displayed as part of the show bgp nexthop command with an invalid status.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to specify the route policy nexthop_A as the policy to use for filtering next hops:

RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)# nexthop route-policy nexthop_A

Related Commands

Command

Description

route-policy (RPL)

Defines a route policy and enters route-policy configuration mode.

show bgp nexthops

Display statistical information about the BGP next hops.

nexthop trigger-delay

To specify the delay for triggering next-hop calculations, use the nexthop trigger-delay command in the appropriate configuration mode. To set the trigger delay to the default value, use the no form of this command.

nexthop trigger-delay { critical delay | non-critical delay }

no nexthop trigger-delay { critical delay | non-critical delay }

Syntax Description

critical

Specifies critical next-hop events. For example, when the next hop is unreachable.

delay

Trigger delay, in milliseconds. Range is 0 to 4294967295.

non-critical

Specifies noncritical next-hop events. For example, Interior Gateway Protocol (IGP) metric changes.

Command Default

critical : 3000 msec for IPv4 address family and IPv6 address family

critical : 0 msec for VPNv4 address family and VPNv6 address family

non-critical : 10000 msec IPv4, IPv6, VPNv4, and VPNv6 address families

Command Modes

IPv4 address family configuration

Pv6 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the nexthop trigger-delay command to allow for a dynamic way for Interior Gateway Protocol (IGP) to converge. This convergence allows BGP to accumulate all notifications and trigger fewer walks, resulting in fewer interprocess communications (IPCs) to the Routing Information Base (RIB) for route addition, deletion, and modification and fewer updates to peers.


Note


A high delay value can be configured to effectively turn off next-hop tracking.


The non-critical delay value must always be set to at least equal or greater than the critical delay value .

The delay should be slightly higher than the time it takes for the IGP to settle into a steady state after some event (IGP convergence time).

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the critical next-hop trigger delay to 3500 milliseconds:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast 
RP/0/RSP0/CPU0:router(config-bgp-af)# nexthop trigger-delay critical 3500 

nsr (BGP)

To activate Border Gateway Protocol (BGP) nonstop routing (NSR), use the nsr command in BGP global configuration mode. To deactivate BGP NSR, use the noform of this command.

nsr

no nsr

Syntax Description

This command has no arguments or keywords.

Command Default

BGP NSR is not activated.

Command Modes

Global configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Release 4.1.0

5000 NSR sessions were supported.

Usage Guidelines

Use the nsr command to enable the Border Gateway Protocol (BGP) Nonstop Routing (NSR) with Stateful Switchover (SSO). This enables all bgp peerings to maintain the BGP state to ensure continuous packet forwarding during events that could interrupt service.

BGP supports 5000 NSR sessions.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable BGP NSR:

  RP/0/RSP0/CPU0:router# configure 
  RP/0/RSP0/CPU0:router(config)# router bgp 120 
  RP/0/RSP0/CPU0:router(config-bgp)# nsr 
  

The following example shows how to disable BGP NSR:

  RP/0/RSP0/CPU0:router# configure
  RP/0/RSP0/CPU0:router(config)# router bgp 120
  RP/0/RSP0/CPU0:router(config-bgp)# no nsr          
  

Related Commands

Command

Description

router bgp

Configures the Border Gateway Protocol (BGP) routing process.

nsr process-failures switchover

Configures failover as a recovery action in case of process failures for active instances to switch over to a standby route processor (RP) or a standby distributed route processor (DRP) to maintain nonstop routing (NSR).

show bgp nsr

Displays Border Gateway Protocol (BGP) nonstop routing (NSR) information.

orf

To specify Outbound Route Filter (ORF) and inbound filtering criteria, use the orf route-policy command in an appropriate configuration mode. To restore the system to its default condition, use the no form of this command.

orf route-policy route-policy-name

no orf route-policy route-policy-name

Syntax Description

route-policy-name

Name of the route policy.

Command Default

No ORF route policy is defined.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VRF IPv4 neighbor address family configuration

VRF IPv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure outbound and inbound filtering criteria:

RP/0/RSP0/CPU0:router(config)#router bgp 6 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)#orf route-policy policy_A  

Related Commands

Command

Description

route-policy (BGP)

Applies a routing policy to updates advertised to or received from a BGP neighbor.

password (BGP)

To enable Message Digest 5 (MD5) authentication on a TCP connection between two Border Gateway Protocol (BGP) neighbors, use the password command in an appropriate configuration mode. To disable MD5 authentication, use the no form of this command.

password { clear | encrypted } password

no password [ clear password | encrypted password ]

Syntax Description

clear

Specifies that an unencrypted password follows. The password must be a case-sensitive, clear-text unencrypted password.

encrypted

Specifies that an encrypted password follows. The password must be a case-sensitive, encrypted password.

password

Password of up to 80 characters. The password can contain any alphanumeric characters. However, if the first character is a number or the password contains a space, the password must be enclosed in double quotation marks; for example, “2 password.”

Command Default

When this command is not specified in the appropriate configuration mode, MD5 authentication is not enabled on a TCP connection between two BGP neighbors.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Configure a password to enable authentication between two BGP peers. Use the password command to verify each segment sent on the TCP connection between the peers. The same password must be configured on both networking devices, otherwise a connection cannot be made. The authentication feature uses the MD5 algorithm. Specifying this command causes the software to generate and check the MD5 digest on every segment sent on the TCP connection.

Configuring a neighbor password does not cause the existing session for a neighbor to end. However, until the new password is configured on the remote router, the local BGP process does not receive keepalive messages from the remote device. If the password is not updated on the remote device by the end of the hold time, the session ends. The hold time can be changed using the timers command or the timers bgp command.

If this command is configured for a neighbor group or neighbor address family group, a neighbor using the group inherits the configuration. Values of commands configured specifically for a neighbor overrides inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure neighbor 172.20.1.1 to use MD5 authentication with the password password1:

RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 172.20.1.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)#remote-as 1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)#password clear password1 

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

password-disable

Overrides any inherited password configuration from a neighbor group or session group for BGP neighbors.

session-group

Creates a session group and enters session group configuration mode.

timers (BGP)

Set the timers for a specific BGP neighbor.

password-disable

To override any inherited password configuration from a neighbor group or session group for Border Gateway Protocol (BGP) neighbors, use the password-disable command in an appropriate configuration mode. To disable overriding any inherited password command, use the no form of this command.

password-disable

no password-disable

Syntax Description

This command has no arguments or keywords.

Command Default

Configured passwords for neighbor and session groups are inherited.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

If you specify a password on a neighbor group or session group, all users of the group inherit the password. Specifying a different password command specifically on a neighbor that uses the group overrides the inherited value. Specifying password-disable on a neighbor that uses the group disables password authentication for the neighbor.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable MD5 authentication for neighbor 172.20.1.1, preventing it from inheriting the password password1 from session group group1:

RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# session-group group1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# password clear password1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 2
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use session-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# password-disable

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

password (BGP)

Enables MD5 authentication on a TCP connection between two BGP neighbors.

session-group

Creates a session group and enters session group configuration mode.

use

Inherits characteristics from a neighbor group, a session group, or an address family group.

precedence

To set the precedence level, use the precedence command in the appropriate configuration mode. To remove the precedence command from the configuration file and restore the system to its default interval values, use the no form of this command.

precedence value

no precedence [ value ]

Syntax Description

value

Value of the precedence. The precedence value can be a number from 0 to 7, or it can be one of the following keywords:

critical —Set packets with critical precedence (5)

flash — Set packets with flash precedence (3)

flash-override —Set packets with flash override precedence (4)

immediate —Set packets with immediate precedence (2)

internet —Set packets with internetwork control precedence (6)

network —Set packets with network control precedence (7)

priority —Set packets with priority precedence (1)

routine —Set packets with routine precedence (0)

Command Default

No default behavior or values

Command Modes

Neighbor configuration

Neighbor session group configuration

Neighbor group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the precedence command to set the precedence value.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the precedence to 2:
RP/0/RSP0/CPU0:router(config)# router bgp 5
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.1.1.1 
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 100
RP/0/RSP0/CPU0:router(config-bgp-nbr)# precedence 2 

rd

To configure a route distinguisher, use the rd command in VRF configuration mode. To disable the route distinguisher, use the no form of this command.

rd { as-number : nn | ip-address : nn | auto }

no rd { as-number : nn | ip-address : nn | auto }

Syntax Description

as-number:nn

  • as-number —16-bit Autonomous system (AS) number of the route distinguisher
    • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
    • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
    • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.
  • nn —32-bit number

ip-address:nn

IP address of the route distinguisher.

  • ip-address —32-bit IP address
  • nn —16-bit number

auto

Automatically assigns a unique route distinguisher.

Command Default

No default behavior or values

Command Modes

VRF configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

Use the rd command to make the prefix unique across multiple VRFs.

Auto assignment of route distinguishers can be done only if a router ID is assigned using the bgp router-id command in BGP router configuration mode. The unique router ID is used for automatic route distinguisher generation.

The following are restrictions when configuring route distinguishers:

  • BGP router-id must be configured before rd auto can be configured
  • Route distinguisher cannot be changed or removed when an IPv4 unicast address family is configured under VRF.
  • BGP router-id cannot be changed or removed when rd auto is configured under a VRF.
  • When rd auto is configured under a VRF, the IP address for the router distinguisher configured under another VRF must be different from that of the BGP router-id
  • If a route distinguisher with same IP address as BGP router-id exists, the rd auto is not permitted.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to automatically assign a unique route distinguisher to VRF instance vrf-1:

RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# vrf vrf-1
RP/0/RSP0/CPU0:router(config-bgp-vrf)# rd auto

Related Commands

Command

Description

bgp router-id

Configures a fixed router ID for a BGP-speaking router.

export route-target

Configures a VRF export route-target extended community.

import route-target

Configures a VRF import route-target extended community.

receive-buffer-size

To set the size of the receive buffers for a Border Gateway Protocol (BGP) neighbor, use the receive-buffer-size command in an appropriate configuration mode. To remove the receive-buffer-size command from the configuration file and restore the system to its default condition in which the software uses the default size, use the no form of this command.

receive-buffer-size socket-size [ bgp-size ]

no receive-buffer-size [ socket-size ] [ bgp-size ]

Syntax Description

socket-size

Size, in bytes, of the receive-side socket buffer. Range is 512 to 131072.

bgp-size

(Optional) Size, in bytes, of the receive buffer in BGP. Range is 512 to 131072.

Command Default

socket-size : 32,768 bytes

bgp-size : 4,032 bytes

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the receive-buffer-size command to increase the buffer size when receiving updates from a neighbor. Using larger buffers can improve convergence time because it allows the software to process a larger number of packets simultaneously. However, allocating larger buffers consumes more memory on the router.


Note


Increasing the socket buffer size uses more memory only when more messages are waiting to be processed by the software. In contrast, increasing the BGP buffer size uses extra memory indefinitely.


If this command is configured for a neighbor group or session group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the receive buffer sizes for neighbor 172.20.1.1 to be 65,536 bytes for the socket buffer and 8192 bytes for the BGP buffer:
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# receive-buffer-size 65536 8192

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

send-buffer-size

Sets the size of the send buffers for a BGP neighbor.

session-group

Creates a session group and enters session group configuration mode.

socket receive-buffer-size

Sets the size of the receive buffers for all BGP neighbors.

redistribute (BGP)

To redistribute routes from one routing domain into Border Gateway Protocol (BGP), use the redistribute command in an appropriate configuration mode. To disable route redistribution, use the no form of this command.

Connected

redistribute connected [ metric metric-value ] [ route-policy route-policy-name ]

no redistribute connected [ metric metric-value ] [ route-policy route-policy-name ]

Enhanced Interior Gateway Routing Protocol (EIGRP)

redistribute eigrp process-id [ match { external | internal } ] [ metric metric-value ] [ route-policy route-policy-name ]

no redistribute eigrp process-id [ match { external | internal } ] [ metric metric-value ] [ route-policy route-policy-name ]

Intermediate System-to-Intermediate System (IS-IS)

redistribute isis process-id [ level | | { 1 | | 1-inter-area | | 2 } ] [ metric metric-value ] [ route-policy route-policy-name ]

no redistribute isis process-id [ level | | { 1 | | 1-inter-area | | 2 } ] [ metric metric-value ] [ route-policy route-policy-name ]

Open Shortest Path First (OSPF)

redistribute ospf process-id

no redistribute ospf process-id

Routing Information Protocol

redistribute rip [ metric metric-value ] [ route-policy route-policy-name ]

no redistribute rip [ metric metric-value ] [ route-policy route-policy-name ]

Static

redistribute static [ metric metric-value ] [ route-policy route-policy-name ]

no redistribute static [ metric metric-value ] [ route-policy route-policy-name ]

Syntax Description

connected

Redistributes connected routes. Connected routes are established automatically when IP is enabled on an interface.

metric metric-value

(Optional) Specifies the Multi Exit Discriminator (MED) attribute used for the redistributed route. Range is 0 to 4294967295. Use a value consistent with the destination protocol.

By default, the Interior Gateway Protocol (IGP) metric is assigned to the route. For connected and static routes the default metric is 0.

route-policy route-policy-name

(Optional) Specifies a configured routing policy to filter redistributed routes. A route policy is used to filter the importation of routes from this source routing protocol to BGP.

eigrp

Specifies that routes are distributed from EIGRP. You must be in IPv4 unicast or multicast address family configuration mode or in VRF IPv4 address family configuration mode.

process-id

For the eigrp keyword, an EIGRP instance name from which routes are to be redistributed.

For the isis keyword, an IS-IS instance name from which routes are to be redistributed.

For the ospf keyword, an OSPF instance name from which routes are to be redistributed.

The process-id value takes the form of a string. A decimal number can be entered, but it is stored internally as a string.

match { internal | external [ 1 | 2 ] | nssa-external [ 1 | 2 ]}

(Optional) Specifies the criteria by which OSPF routes are redistributed into other routing domains. It can be one or more of the following:

  • internal —Routes that are internal to a specific autonomous system (intra- and inter-area OSPF routes).
  • external [ 1 | 2 ]—Routes that are external to the autonomous system, but are imported into OSPF as Type 1 or Type 2 external routes.
  • nssa-external [ 1 | 2 ]—Routes that are external to the autonomous system, but are imported into OSPF as Type 1 or Type 2 not-so-stubby area (NSSA) external routes.

For the external and nssa-external options, if a type is not specified, then both Type 1 and Type 2 are assumed.

isis

Specifies that routes are distributed from the IS-IS protocol.

Redistribution from IS-IS is allowed under IPv4 unicast, IPv4 multicast, IPv6 unicast, and address-families. Redistribution is not allowed under VPNv4 address-families.

level { 1 | 1-inter-area | 2 }

(Optional) Specifies the IS-IS level from which routes are redistributed. It can be one of the following:

  • 1 —Routes are redistributed from Level 1 routes.
  • 1-inter-area —Routes are redistributed from Level 1 interarea routes.
  • 2 —Routes are redistributed from Level 2 routes.

ospf

Specifies that routes are distributed from the OSPF protocol. You must be in IPv4 unicast or multicast address family configuration mode or in VRF IPv4 address family configuration mode.

rip

Specifies that routes are distributed from RIP. You must be in IPv4 unicast or multicast address family configuration mode.

static

Redistributes IP static routes.

Command Default

Route redistribution is disabled.

For IS-IS, the default is to redistribute Level 1 and Level 2 routes.

For OSPF, the default is to redistribute internal, external, and NSSA external routes of Type 1 and Type 2.

By default, the Interior Gateway Protocol (IGP) metric is assigned to the route. For connected and static routes the default metric is 0.

metric metric-value: 0

match { internal | external [ 1 | 2 ] | nssa-external [ 1 | 2 ]}: If no match is specified, the default is to match all routes.

Command Modes

IPv4 address family configuration, both unicast and multicast (connected, eigrp, isis, ospf, rip, and static are supported)


            IPv6 address family configuration, both unicast and multicast (connected, eigrp,
               isis,
            

            ospfv3,
            and static are supported)
        

VRF IPv4 address family configuration (
               connected
            
,
               eigrp
            
,
               ospf
            
,
               rip
            
, and
               static
            
are supported)

VRF IPv6 address family configuration (
               connected
            
,
               eigrp
            
, and
               static
            
are supported)

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines


Note


When redistributing routes (into BGP) using both command keywords for setting or matching of attributes and a route policy, the routes are run through the route policy first, followed by the keyword matching and setting.


Each instance of a protocol may be redistributed independently of the others. Changing or removing redistribution for a particular instance does not affect the redistribution capability of other protocols or other instances of the same protocol.

Networks specified using the network command are not affected by the redistribute command; that is, the routing policy specified in the network command takes precedence over the policy specified through the redistribute command.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to redistribute IP Version 4 (IPv4) unicast OSPF routes from OSPF instance 110 into BGP:
RP/0/RSP0/CPU0:router(config)# router bgp 109
RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# redistribute ospf 110

Related Commands

Command

Description

network (BGP)

Specifies a local network that the BGP routing process should originate and advertise to its neighbors.

remote-as (BGP)

To create a Border Gateway Protocol (BGP) neighbor and begin the exchange of routing information, use the remote-as command in an appropriate configuration mode. To delete the entry for the BGP neighbor, use the no form of this command.

remote-as as-number

no remote-as [ as-number ]

Syntax Description

as-number

Autonomous system (AS) to which the neighbor belongs.

  • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
  • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
  • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.

Command Default

No BGP neighbors exist.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported.

Usage Guidelines

Use the remote-as command to create a neighbor and assign it a remote autonomous system number. A neighbor must have a remote autonomous system number before any other commands can be configured for it. Removing the remote autonomous system from a neighbor causes the neighbor to be deleted. You cannot remove the autonomous system number if the neighbor has other configuration.


Note


We recommend that you use the no neighbor command rather than the no remote-as command to delete a neighbor.


A neighbor specified with a remote autonomous system number that matches the autonomous system number specified in the router bgp command identifies the neighbor as internal to the local autonomous system. Otherwise, the neighbor is considered external.

Configuration of the remote-as command for a neighbor group or session group using the neighbor-group command or session-group command causes all neighbors using the group to inherit the characteristics configured with the command. Configuring the command directly for the neighbor overrides the value inherited from the group.

In the neighbor configuration submode, configuring use of a session group or neighbor group for which remote-as is configured creates a neighbor and assigns it an autonomous system number if the neighbor has not already been created.


Note


Do not combine remote-as commands and no use neighbor-group commands, or remote-as commands and no use session-group commands, in the same configuration commit.


Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to assign autonomous system numbers on two neighbors, neighbor 10.0.0.1, (internal) and neighbor 192.168.0.1 (external), setting up a peering session that shares routing information between this router and each of these neighbors:

RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# session-group group2
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)#exit 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)#use session-group group2 

The following example shows how to configure a session group called group2 with an autonomous system number 1. Neighbor 10.0.0.1 is created when it inherits the autonomous system number 1 from session group group2.

RP/0/RSP0/CPU0:router(config)#router bgp 1 
RP/0/RSP0/CPU0:router(config-bgp)# session-group group2
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use session-group group2

Related Commands

Command

Description

neighbor (BGP)

Enters neighbor configuration mode for configuring BGP routing sessions.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

router bgp

Configures the BGP routing process.

session-group

Creates a session group and enters session group configuration mode.

use

Inherits characteristics from a neighbor group, session group, or address family group.

remove-private-as

To remove private autonomous system numbers from autonomous system paths when generating updates to external neighbors, use the remove-private-as command in an appropriate configuration mode. To place the router in the default state in which it does not remove private autonomous system numbers, use the no form of this command.

remove-private-as [ inheritance-disable ] [entire-aspath]

no remove-private-as [ inheritance-disable ] [entire-aspath]

Syntax Description

inheritance-disable

(Optional) Permits the feature to be disabled from a neighbor group or address family group instead of being inherited.

entire-aspath

(Optional) Removes the entire private autonomous system numbers from an autonomous system path only if all ASes in the path are private.

Command Default

When this command is not specified in the appropriate configuration mode, private autonomous system numbers are not removed from updates sent to external neighbors.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VPNv4 neighbor address family configuration

VRF IPv4 neighbor address family configuration

VPNv4 neighbor group address family configuration

VRF IPv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Release 3.9.2

The entire-aspath keyword was supported.

Usage Guidelines

This feature is available for external BGP (eBGP) neighbors only.

When an update is passed to the external neighbor, the software drops any leading autonomous system sequence in the autonomous system path if the sequence contains only private autonomous system numbers and does not contain the autonomous system number of the neighbor.

If this command is used in a BGP confederation, the element following the confederation portion of the autonomous system path, if a sequence, is considered the leading sequence.

The private autonomous system values range from 64512 to 65535.

If this command is configured for a neighbor group or address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Use the entire-aspath to removes the entire private autonomous system numbers from an autonomous system path only if all ASes in the path are private.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows a configuration that removes the private autonomous system number from the IP Version 4 (IPv4) unicast updates sent to 172.20.1.1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# remove-private-as

The following example shows how to disable the remove private autonomous system number feature for neighbor 172.20.1.1, preventing this feature from being automatically inherited from address family group group1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# remove-private-as
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# use af-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# remove-private-as inheritance-disable

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

remote-as (BGP)

Allows entries to the BGP neighbor table.

retain local-label

To retain the local label until the network is converged, use the retain local-label command in an appropriate address family configuration mode. To disable the retaining of the local label, use the no form of this command.

retain local-label minutes

no retain local-label

Syntax Description

minutes

Local retention time in minutes. The range is 3 to 60 minutes. The default retention time is 5 minutes.

Command Default

minutes : 5

Command Modes

L2VPN address family configuration

VPNv4 address family configuration

VPNv6 address family configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable local label retention for 5 minutes:

RP/0/RSP0/CPU0:routerconfigure
RP/0/RSP0/CPU0:router(config)# router bgp 100
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# retain local-label 5

Related Commands

Command

Description

additional-paths install backup

Installs a backup path into the forwarding table

advertise best-external

Advertises the best-external path to the iBGP and route-reflector peers.

retain route-target

To accept received updates with specified route targets, use the retain route-target command in an appropriate configuration mode. To disable the retaining of routes tagged with specified route targets, use the no form of this command.

retain route-target { all | route-policy route-policy-name }

no retain route-target [ all | route-policy route-policy-name ]

Syntax Description

all

Accepts received updates containing at least one route target.

route-policy router-policy-name

Accepts received updates accepted by a specified route filter policy.

Command Default

The default is to accept all route targets.

Command Modes

VPNv4 address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the retain route-target command to configure a route reflector (RR) to retain routes tagged with specific route targets (RT).

The retain route-target is a required command for Inter-AS option B ASBR. By default, an Inter-AS option B ASBR needs the retain route-target configured to get VPNv4 BGP table from PE routers, either with the all or with the route-policy option.

A provider edge (PE) router is not required to hold all VPNv4 routes. The PE router holds only routes that match the import RT of the VPNs configured on it, but a RR must retain all VPNv4 routes because it may peer with PE routers and different PEs may require different RT-tagged VPNv4 routes. Configuring an RR to hold only routes that have a defined set of RT communities and configuring some of these RRs to service a different set of VPNs provides scalability to the RRs. A PE can be configured to peer with all RRs that service the VPN routing and forwarding (VRF) instances configured on the PE. When a new VRF is configured with an RT for which the PE does not already hold routes, the PE issues route refresh requests to the RRs and gets the relevant VPN routes.

The route-policy route-policy-name keyword and argument takes the policy name that lists the extended communities that a path should have for the RR to retain the path.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure RR to retain all routes with the route filter policy ft-policy-A:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# address-family vpnv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-af)# retain route-target route-filter ft-policy-A

Related Commands

Command

Description

import route-target

Configures a VRF import route-target extended community.

route-policy (BGP)

To apply a routing policy to updates advertised to or received from a Border Gateway Protocol (BGP) neighbor, use the route-policy command in an appropriate configuration mode. To disable applying routing policy to updates, use the no form of this command.

route-policy route-policy-name [ parameter1, parameter2, . . . , parametern ] { in | | out }

no route-policy route-policy-name [ parameter1, parameter2, . . . , parametern ] { in | | out }

Syntax Description

route-policy-name

Name of route policy. Up to 16 parameters can follow the route-policy-name, enclosed in brackets ([ ]).

in

Applies policy to inbound routes.

out

Applies policy to outbound routes.

Command Default

No policy is applied.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VPNv4 address family group configuration

VPNv4 neighbor address family configuration

VRF IPv4 neighbor address family configuration

VPNv4 neighbor group address family configuration

VRF IPv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the route-policy command to specify a routing policy for an inbound or outbound route. The policy can be used to filter routes or modify route attributes. The route-policy command is used to define a policy.


Note


Configuring a large number of uniquely named outbound neighbor policies can adversely affect performance. This is true even if the uniquely named route policies are functionally identical. The user is discouraged from configuring multiple functionally identical route policies for use with this command. For example, if Policy A and Policy B are identical but named for different neighbors, the two policies should be configured as a single policy.


If the route-policy command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to apply the In-Ipv4 policy to inbound IP Version 4 (IPv4) unicast routes from neighbor 172.20.1.1:
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# route-policy In-Ipv4 in

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

route-policy (RPL)

Defines a route policy and enters route-policy configuration mode.

route-reflector-client

To configure the router as a Border Gateway Protocol (BGP) route reflector and configure the specified neighbor as its client, use the route-reflector-client command in an appropriate configuration mode. To disable configuring the neighbor as a client, use the no form of this command.

route-reflector-client [ inheritance-disable ]

no route-reflector-client [ inheritance-disable ]

Syntax Description

inheritance-disable

(Optional) Allows the configuration inherited from a neighbor group or address family group to be overridden.

Command Default

The neighbor is not treated as a route reflector client.

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VPNv4 address family group configuration

VPNv4 neighbor address family configuration

VPNv4 neighbor group address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

This command is restricted to internal BGP (iBGP) neighbors only.

Use the route-reflector-client command to configure the local router as the route reflector and the specified neighbor as one of its clients. All neighbors configured with this command are members of the client group, and the remaining iBGP peers are members of the nonclient group for the local route reflector.

By default, all iBGP speakers in an autonomous system must be fully meshed with each other, and neighbors do not readvertise iBGP learned routes to other iBGP neighbors.

With route reflection, all iBGP speakers need not be fully meshed. An iBGP speaker, the route reflector, passes learned iBGP routes to some number of iBGP client neighbors. Learned iBGP routes eliminate the need for each router running BGP to communicate with every other device running BGP in the autonomous system.

The local router is a route reflector as long as it has at least one route reflector client.

If this command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows neighbor at 172.20.1.1 configured as a route reflector client for IP Version 4 (IPv4) unicast routes:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 140
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# route-reflector-client

The following example disables the route-reflector client for neighbor 172.20.1.1, preventing this feature from being automatically inherited from address family group group1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# route-reflector-client
RP/0/RSP0/CPU0:router(config-bgp-afgrp)#exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 140
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# use af-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# route-reflector-client inheritance-disable

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

bgp cluster-id

Configures the cluster ID if the BGP cluster has more than one route reflector.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

router bgp

To configure the Border Gateway Protocol (BGP) routing process, use the router bgp command in global configuration mode. To remove all BGP configurations and terminate the BGP routing process, use the no form of this command.

router bgp as-number

no router bgp [ as-number ]

Syntax Description

as-number

Number that identifies the autonomous system (AS) in which the router resides.

  • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
  • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
  • Range for 4-byte Autonomous system numbers (ASNs) is asdot format is 1.0 to 65535.65535.

Command Default

No BGP routing process is enabled.

Command Modes

Global configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system number notation was supported.

Usage Guidelines

Use the router bgp command to set up a distributed routing core that automatically guarantees the loop-free exchange of routing information between autonomous systems.

Task ID

Task ID

Operations

bgp

read, write

rib

read, write

Examples

The following example shows how to configure a BGP process for autonomous system 120:
RP/0/RSP0/CPU0:router(config)# router bgp 120

send-buffer-size

To set the size of the send buffers for a Border Gateway Protocol (BGP) neighbor, use the send-buffer-size command in an appropriate configuration mode. To set the size of the send buffers to the default values, use the no form of this command.

send-buffer-size socket-size [ bgp-size ]

no send-buffer-size [ socket-size ] [ bgp-size ]

Syntax Description

socket-size

Size, in bytes, of the send-side socket buffer. Range is 4096 to 131072.

bgp-size

(Optional) Size, in bytes, of the BGP process send buffer. Range is 4096 to 131072.

Command Default

socket-size : 10240 bytes

bgp-size : 4096 bytes

Use the socket send-buffer-size command to change the defaults.

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the send-buffer-size command to increase the buffer size employed when sending updates to a neighbor. Using larger buffers can improve convergence time because the software can process more packets simultaneously. However, allocating larger buffers uses more memory on the router.


Note


Increasing the socket buffer size uses more memory only when more messages are waiting to be processed by the software. In contrast, increasing the BGP buffer size uses more memory indefinitely.


If this command is configured for a neighbor group or session group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to set the send buffer sizes for neighbor 172.20.1.1 to be 8192 bytes for both the socket buffer and the BGP buffer:
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# send-buffer-size 8192 8192

Related Commands

Command

Description

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

receive-buffer-size

Sets the size of the receive buffers for a BGP neighbor.

session-group

Creates a session group and enters session group configuration mode.

socket send-buffer-size

Sets the size of the send buffers for all BGP neighbors.

send-community-ebgp

To specify that community attributes should be sent to an external Border Gateway Protocol (eBGP) neighbor, use the send-community-ebgp command in an appropriate configuration mode. To disable sending community attributes to an eBGP neighbor, use the no form of this command.

send-community-ebgp [ inheritance-disable ]

no send-community-ebgp [ inheritance-disable ]

Syntax Description

inheritance-disable

(Optional) Allows configuration inherited from a neighbor group or address family group to be overridden.

Command Default

Community (COMM) attributes are NOT sent to eBGP peers (including PE-CE peers).

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VRF IPv4 neighbor address family configuration

VPNv4 neighbor address family configuration

VRF IPv6 neighbor address family configuration

VPNv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

Use the send-community-ebgp command to control whether community attributes are sent to eBGP neighbors. This command cannot be configured for iBGP neighbors as community attributes are always sent to iBGP neighbors.

When IOS XR BGP updates community attributes for eBGP VPN peers (VPNv4 or VPNv6), there is no need to configure the send-community-ebgp command separately. The community attributes are updated by default.

If this command is configured for a neighbor group or address family group, all neighbors using the group inherit the configuration. Configuring the command specifically for a neighbor overrides inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to disable the router that sends community attributes to neighbor 172.20.1.1 for IP Version 4 (IPv4) multicast routes:

RP/0/RSP0/CPU0:router(config)#router bgp 140 
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# send-community-ebgp

The following example shows how to disable the delivery of community attributes to neighbor 172.20.1.1, preventing this feature from being inherited from address family group group1:

RP/0/RSP0/CPU0:router(config)#router bgp 140 
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# send-community-ebgp
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# use af-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# send-community-ebgp inheritance-disable

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

send-extended-community-ebgp

Specifies that extended community attributes are sent to eBGP neighbors.

send-extended-community-ebgp

To specify that extended community attributes should be sent to external Border Gateway Protocol (eBGP) neighbors, use the send-extended-community-ebgp command in an appropriate configuration mode. To disable sending extended community attributes to eBGP neighbors, use the no form of this command.

send-extended-community-ebgp [ inheritance-disable ]

no send-extended-community-ebgp [ inheritance-disable ]

Syntax Description

inheritance-disable

(Optional) Allows configurations inherited from a neighbor group or address family group to be overridden.

Command Default

Extended community (EXTCOMM) attributes are NOT sent to eBGP peers (including PE-CE peers).

Command Modes

IPv4 address family group configuration

IPv6 address family group configuration

IPv4 neighbor address family configuration

IPv4 neighbor group address family configuration

IPv6 neighbor group address family configuration

VRF IPv4 neighbor address family configuration

VPNv4 neighbor address family configuration

VRF IPv6 neighbor address family configuration

VPNv6 neighbor address family configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The disable keyword was replaced with the inheritance-disable keyword.

Usage Guidelines

Use the send-extended-community-ebgp command to control whether extended community attributes are sent to eBGP neighbors. This command cannot be used for iBGP neighbors as extended community attributes are always sent to iBGP neighbors.

When IOS XR BGP updates community attributes for eBGP VPN peers (VPNv4 or VPNv6), there is no need to configure the send-extended-community-ebgp command separately. The community attributes are updated by default.

If this command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to configure the router to send extended community attributes to neighbor 172.20.1.1 for IP Version 4 (IPv4) multicast routes:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# send-extended-community-ebgp

The following example shows how to disable the delivery of extended community attributes to neighbor 172.20.1.1, preventing this feature from being automatically inherited from address family group group1:
RP/0/RSP0/CPU0:router(config)# router bgp 140
RP/0/RSP0/CPU0:router(config-bgp)# af-group group1 address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# send-extended-community-ebgp
RP/0/RSP0/CPU0:router(config-bgp-afgrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 172.20.1.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# address-family ipv4 multicast
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# use af-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr-af)# send-extended-community-ebgp inheritance-disable

Related Commands

Command

Description

af-group

Creates an address family group for BGP neighbors and enters address family group configuration mode.

neighbor-group

Creates a neighbor group and enters neighbor group configuration mode.

send-community-ebgp

Specifies that community attributes should be sent to an eBGP neighbor.

session-group

To create a session group and enter session group configuration mode, use the session-group command in router configuration mode. To remove a session group and delete all configurations associated with it, use the no form of this command.

session-group name

no session-group name

Syntax Description

name

Name of the session group.

Command Default

No session groups are created.

Command Modes

Router configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

Use the session-group command to create a session group from which neighbors can inherit configuration that is address family-independent. That is, session groups cannot have address family-specific configuration. This command enters the session group configuration mode in which configuration for a session group is entered.

Many commands can be configured in both session group configuration mode and neighbor configuration mode.

Use of session groups saves time and reduces the router configuration size. Because the configuration of a session group can be inherited by any number of neighbors, use of the group can eliminate the need to copy long or complex configurations on each of a large number of neighbors. A neighbor can inherit all configuration from a session group simply by configuring the use command. Specific inherited session group configuration commands can be overridden for a specific neighbor by explicitly configuring the command for the specific neighbor.

The no form of this command causes all of the configuration for the session group to be removed. You cannot use the no form of this command if removing the group would leave one or more neighbors without a configured remote autonomous system number.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows a session group called group1 that is used by two neighbors, 10.0.0.1 and 10.0.0.2. Because group1 is a session group, it contains only address family-independent configuration. And because group1 is used by neighbors 10.0.0.1 and 10.0.0.2, they inherit the configuration of the group.
RP/0/RSP0RP0/CPU0:router(config)# router bgp 1
RP/0/RSP0RP0/CPU0:router(config-bgp)# session-group group1
RP/0/RSP0RP0/CPU0:router(config-bgp-sngrp)# remote-as 1
RP/0/RSP0RP0/CPU0:router(config-bgp-sngrp)# advertisement-interval 2
RP/0/RSP0RP0/CPU0:router(config-bgp-sngrp)# exit
RP/0/RSP0RP0/CPU0:router(config-bgp)# neighbor 10.0.0.1
RP/0/RSP0RP0/CPU0:router(config-bgp-nbr)# use session-group group1
RP/0/RSP0RP0/CPU0:router(config-bgp-nbr)# exit
RP/0/RSP0RP0/CPU0:router(config-bgp)# neighbor 10.0.0.2
RP/0/RSP0RP0/CPU0:router(config-bgp-nbr)# use session-group group1

The following example shows a session group called group1 used by two neighbors, 10.0.0.1 and 10.0.0.2. Because group1 is a session group, it contains only address family-independent configuration. And because group1 is used by neighbors 10.0.0.1 and 10.0.0.2, they inherit the configuration of the group. However, the password password1 configuration from group1 is overridden for neighbor 10.0.0.2, using the password-disable command in the neighbor 10.0.0.2 configuration submode.
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# session-group group1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# remote-as 1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# advertisement-interval 2
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# password password1
RP/0/RSP0/CPU0:router(config-bgp-sngrp)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use session-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# exit
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 10.0.0.2
RP/0/RSP0/CPU0:router(config-bgp-nbr)# use session-group group1
RP/0/RSP0/CPU0:router(config-bgp-nbr)# password-disable

session-open-mode

To establish a Border Gateway Protocol (BGP) session with a specific TCP open mode, use the session-open-mode command in an appropriate configuration mode. To restore the default state, use the no form of this command.

session-open-mode { active-only | both | passive-only }

no session-open-mode [ active-only | both | passive-only ]

Syntax Description

active-only

Ensures that the BGP session can be established only when the request is initiated by the local end (active-open request) and all passive-open requests (from the other end) are rejected by the local BGP.

both

Allows BGP sessions to be established from both incoming or outgoing TCP connection requests, with one being rejected in the event of a request collision.

passive-only

Ensures that the local BGP does not initiate any TCP open requests and the session can be established only when the request comes from the remote end.

Command Default

The default is both .

Command Modes

Neighbor configuration

VRF neighbor configuration

Neighbor group configuration

Session group configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

BGP, by default, tries to initiate an active TCP connection whenever a new neighbor is configured. A remote neighbor may also initiate the TCP connection before the local BGP can initiate the connection. This initiation of a TCP connection by a remote neighbor is considered a passive-open request and it is accepted by the local BGP. This default behavior can be modified using the session-open-mode command.


Note


The BGP connection is not opened and, as a result the BGP session, is not established if both the peering neighbors use the same nondefault TCP session open mode—active-only or passive-only. If both ends are configured with active-only, each neighbor rejects the TCP open request from the other end. One neighbor must be configured as passive-only or both. Similarly, if both neighbors are configured with passive-only, neither neighbor initiates the TCP open request and the BGP session is not established. Again, one neighbor must be configured as active-only or both. There is one exception. A connection open request from a neighbor that is configured with the TCP session open mode to be passive-only is processed to detect whether there is a connection collision before the request is rejected. This exception enables the local BGP to reset the session if the remote neighbor goes down and it is not detected by the local router.


Use the session-open-mode command when it may be necessary to preconfigure a neighbor that does not exist. Ensure that BGP does not spend any time actively trying to set up a TCP session with the neighbor. A BGP session does not come up between two neighbors, both of which configure the same nondefault value ( active-only or passive-only keyword) for this command.

Task ID

Task ID

Operations

bgp

read, write

Examples

The following example shows how to enable a BGP session on router bgp 1:
RP/0/RSP0/CPU0:router(config)# router bgp 1
RP/0/RSP0/CPU0:router(config-bgp)# neighbor 45.67.89.01
RP/0/RSP0/CPU0:router(config-bgp-nbr)# session-open-mode active-only

show bgp

To display entries in the Border Gateway Protocol (BGP) routing table, use the show bgp command in EXEC mode.

show bgp [ ipv4 { unicast | multicast | labeled-unicast | all | tunnel } | ipv6 { unicast | multicast | all | labeled-unicast } | all { unicast | multicast | all | labeled-unicast | mdt | tunnel } | vpnv4 { unicast } [ rd rd-address ] | vrf { vrf-name | all } [ ipv4 { unicast | labeled-unicast } | ipv6 {unicast | } ] | [ rd rd-address ] | ] [ ip-address [ { mask | /prefix-length } [ longer-prefixes | unknown-attributes | bestpath-compare ] ] ] [standby] [detail]

Syntax Description

ipv4

(Optional) Specifies IP Version 4 address prefixes.

unicast

(Optional) Specifies unicast address prefixes.

multicast

(Optional) Specifies multicast address prefixes.

labeled-unicast

(Optional) Specifies labeled unicast address prefixes.

all

(Optional) For subaddress families, specifies prefixes for all subaddress families.

tunnel

(Optional) Specifies tunnel address prefixes.

ipv6

(Optional) Specifies IP Version 6 address prefixes.

all

(Optional) For address family, specifies prefixes for all address families.

vpnv4 unicast

(Optional) Specifies VPNv4 unicast address families.

rd rd-address

(Optional) Displays routes with a specific route distinguisher.

vrf

(Optional) Specifies VPN routing and forwarding (VRF) instance.

vrf-name

(Optional) Name of a VRF.

all

(Optional) For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

(Optional) For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

(Optional) For VRF, specifies IPv6 unicast address families.

ip-address

(Optional) Network address, entered to display a particular network in the BGP routing table. If the network address is omitted, then all networks in the BGP routing table are displayed. If the network mask and prefix length is omitted, then the software displays the longest matching prefix for the network address.

mask

(Optional) Network mask of the BGP route to match.

/ prefix-length

(Optional) Prefix length of the BGP route to match. A slash (/) must precede the decimal value.

longer-prefixes

(Optional) Displays a route with the specified prefix length and more-specific routes if available. The longer-prefixes keyword is available when the ip-address and mask or /prefix-length arguments are specified.

unknown-attributes

(Optional) Includes unknown, transitive attributes. The unknown-attributes keyword is available when the ip-address and mask or /prefix-length arguments are specified.

bestpath-compare

(Optional) Displays route and best-path comparison information. The bestpath-compare keyword is available when the ip-address and mask or /prefix-length arguments are specified.

Command Default

If no address family or subaddress family is specified, the default address family and subaddress family specified using the set default-afi and set default-safi commands are used.

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

Asplain format for 4-byte Autonomous system numbers notation was supported. The input parameters and output were modified to display 4-byte autonomous system numbers and extended communities in either asplain or asdot notations.

Release 4.1.1

The command output was modified to display from BGP Accept Own configuration.

Release 4.0.0

The command output was modified to display BGP add-path information.

Usage Guidelines


Note


The set default-afi command is used to specify the default address family for the sessions and the set default-safi command is used to specify the default subaddress family for the session. See the Cisco ASR 9000 Series Aggregation Services Router System Management Command Reference for detailed information and syntax for the set default-afi and set default-safi commands. If you do not specify a default address family, the default address family is IPv4. If you do not specify a default subaddress family, the default subaddress family is unicast.


BGP contains a separate routing table for each address family and subaddress family combination that has been configured. The address family and subaddress family options specify the routing table to be examined. If the all keyword is specified for an address family or a subaddress family, each matching routing table is examined in turn.


Note


Running the show bgp command immediately after configuring a large and complex route policy may result in timeout of the system database shown through an error message (SYSDB-SYSDB-6-TIMEOUT_EDM). It is recommended, that the show command be run, after the new route policy takes effect.


Use the show bgp ip-address { mask | / prefix-length } command to display detailed information for a specific route. If the mask and prefix length are omitted, the details of the longest matching prefix for the IP address are displayed.

Use the show bgp command to display all routes in the specified BGP routing table. Use the show bgp ip-address { mask | / prefix-length } longer-prefixes command to display those routes more specific than a particular prefix.

Use the unknown-attributes keyword to display details of any transitive attributes associated with a route that are not understood by the local system.

Task ID

Task ID

Operations

bgp

read

Examples

The following is sample output from the show bgp command in EXEC mode:

 
RP/0/RSP0/CPU0:router#show bgp
 BGP router identifier 172.20.1.1, local AS number 1820
 BGP generic scan interval 60 secs
 BGP table state: Active
 Table ID: 0xe0000000
 BGP main routing table version 3
 Dampening enabled
 BGP scan interval 60 secs
 
 Status codes: s suppressed, d damped, h history, * valid, > best
               i - internal, S stale
 Origin codes: i - IGP, e - EGP, ? - incomplete
 
 Network             Next Hop           Metric LocPrf Weight Path
 * i10.3.0.0/16      172.20.22.1             0    100      0 1800 1239 ?
 *>i                 172.20.16.1             0    100      0 1800 1239 ?
 * i10.6.0.0/16      172.20.22.1             0    100      0 1800 690 568 ?
 *>i                 172.20.16.1             0    100      0 1800 690 568 ?
 * i10.7.0.0/16      172.20.22.1             0    100      0 1800 701 35 ?
 *>i                 172.20.16.1             0    100      0 1800 701 35 ?
 *                   192.168.40.24                         0 1878 704 701 35 ?
 * i10.8.0.0/16      172.20.22.1             0    100      0 1800 690 560 ?
 *>i                 172.20.16.1             0    100      0 1800 690 560 ?
 *                   192.168.40.24                         0 1878 704 701 560 ?
 * i10.13.0.0/16     172.20.22.1             0    100      0 1800 690 200 ?
 *>i                 172.20.16.1             0    100      0 1800 690 200 ?
 *                   192.168.40.24                         0 1878 704 701 200 ?
 * i10.15.0.0/16     172.20.22.1             0    100      0 1800 174 ?
 *>i                 172.20.16.1             0    100      0 1800 174 ?
 * i10.16.0.0/16     172.20.22.1             0    100      0 1800 701 i
 *>i                 172.20.16.1             0    100      0 1800 701 i
 *                   192.168.40.24                         0 1878 704 701 i
 
 Processed 8 prefixes, 8 paths
 
This table describes the significant fields shown in the display.

Table 3 show bgp Field Descriptions

Field

Description

BGP router identifier

BGP identifier for the local system.

local AS number

Autonomous system number for the local system.

  • Range for 2-byte Autonomous system numbers (ASNs) is 1 to 65535.
  • Range for 4-byte Autonomous system numbers (ASNs) in asplain format is 1 to 4294967295.
  • Range for 4-byte Autonomous system numbers (ASNs) in asdot format is 1.0 to 65535.65535.

BGP generic scan interval

Interval (in seconds) between scans of the BGP table by a generic scanner.

BGP table state

State of the BGP database.

Table ID

BGP database identifier.

BGP main routing table version

Last version of the BGP database that was installed into the main routing table.

Dampening enabled

Dampening is enabled for the routes in this BGP routing table.

BGP scan interval

Interval (in seconds) between BGP scans for the specified address family and subaddress family.

Status codes

Status of the table entry. The status is displayed as a three-character field at the beginning of each line in the table. The first character may be (in order of precedence):

S—Path is stale, indicating that a graceful restart is in progress with the peer from which the route was learned.

s—Path is more specific than a locally sourced aggregate route and has been suppressed.

*—Path is valid.

The second character may be (in order of precedence):

>—Path is the best path to use for that network.

d—Path is dampened.

h—Path is a history entry, representing a route that is currently withdrawn, but that is being maintained to preserve dampening information. Such routes should never be marked as valid.

The third character may be:

i—Path was learned by an internal BGP (iBGP) session.

Origin codes

Origin of the path. The origin code is displayed at the end of each line in the table. It can be one of the following values:

i—Path originated from an Interior Gateway Protocol (IGP) and was sourced by BGP using a network or aggregate-address command.

e—Path originated from an Exterior Gateway Protocol (EGP).

?—Origin of the path is not clear. Usually, this is a route that is redistributed into BGP from an IGP.

Network

IP prefix and prefix length for a network.

Next Hop

IP address of the next system that is used when a packet is forwarded to the destination network. An entry of 0.0.0.0 indicates that the router has a non-BGP route to this network.

Metric

Value of the interautonomous system metric, otherwise known as the Multi Exit discriminator (MED) metric.

LocPrf

Local preference value. This is used to determine the preferred exit point from the local autonomous system. It is propagated throughout the local autonomous system.

Weight

Path weight. Weight is used in choosing the preferred path to a route. It is not advertised to any neighbor.

Path

Autonomous system path to the destination network. At the end of the path is the path origin code.

The following is sample output from the show bgp command with the network specified:

RP/0/RSP0/CPU0:router# show bgp 11.0.0.0/24
BGP router table entry for 11.0.0.0/24
 Versions:
  Process          bRIB/RIB  SendTblVer
  Speaker                 2           2
 
 Paths: (3 available, best #1)
   Advertised to update-groups (with more than one peer):
     0.1
   Advertised to peers (in unique update groups):
     10.4.101.1
   Received by speaker 0
   Local
     0.0.0.0 from 0.0.0.0 (10.4.0.1)
       Origin IGP, metric 0, localpref 100, weight 32768, valid, local, best 
   Received by speaker 0
   2 3 4
     10.4.101.1 from 10.4.101.1 (10.4.101.1)
       Origin IGP, localpref 100, valid, external
   Received by speaker 0
   Local
     10.4.101.2 from 10.4.101.2 (10.4.101.2)
       Origin IGP, localpref 100, valid, internal 

This table describes the significant fields shown in the display.



Table 4 show bgp prefix length Field Descriptions

Field

Description

BGP router table entry

Network that is being displayed.

Versions

List of the network versions in each BGP process.

Process

Name of the BGP process.

bRIB/RIB

Version of the network for sending to the RIB. You can compare this version with the bRIB/RIB version for the process (at the top of show bgp summary ) to verify whether the network has been sent to the RIB.

SendTblVer

Version of the network for advertising to neighbors. This can be compared with the neighbor version to determine whether the network has been advertised to a particular neighbor.

Paths

List of paths for the network (that is, routes to reach the network). The number of paths and the index of the best path are given.

not advertised to any peer

Best path was received with a NO_ADVERTISE community and is not advertised to any neighbor.

not advertised to EBGP peer

Best path was received with a NO_EXPORT community and is not advertised to any eBGP neighbor.

not advertised outside local AS

Best path was received with a LOCAL_AS community and is not advertised to peers outside the local AS.

Advertisements of this net are suppressed by an aggregate

Network is a more-specific prefix of a configured aggregate and has been suppressed. It is not advertised to any neighbors unless they have an unsuppress-map configured.

Advertised to update-groups

List of update-groups to which the net has been advertised. Update-groups that have only one peer are not listed here.

Advertised to peers

List of neighbors to which the net has been advertised to. Neighbors that are in one of the update-groups listed above are not listed separately. Only neighbors that are in unique update-groups are listed.

Received by speaker 0

BGP process where the path originated. This is always “speaker 0” for standalone mode. It will be the speaker-id when BGP is in distributed mode.

AS Path

Autonomous system (AS) path that was received for the path. If the AS path is empty, then “Local” is displayed. This is the case for paths that are locally generated on this router or on a neighboring router within the same AS.

aggregated by

If the path is an aggregate, the router-id of the router that performed the aggregation.

suppressed due to dampening

Path has been suppressed due to the configured path dampening.

history entry

Path is withdrawn, but a copy is kept to store the dampening information.

Received from a RR-client

Path was received from a route reflector client.

received-only

If soft reconfiguration inbound is configured, the path was received but dropped by inbound policy, or was accepted and modified. In either event, the received-only value is a copy of the original, unmodified path.

received & used

If soft reconfiguration inbound is configured, the path was received and accepted by inbound policy, but not modified.

stale

Neighbor from which the path was received is down, and the path is kept and marked as stale to support graceful restart.

<nexthop> from <neighbor> (<router-id>)

Next hop for the path. If the next hop is known by a mechanism outside BGP (for example, for redistributed paths), then 0.0.0.0 is displayed. After the next hop, the neighbor from whom the path was received is displayed, along with the neighbor’s router-id. If the path was locally generated (for example, an aggregate or redistributed path), then 0.0.0.0 is displayed for the neighbor address.

Origin

IGP: the path originated from an IGP.

EGP: the path originated from an EGP.

incomplete: the origin of the path is unknown.

metric

MED value of the path.

localpref

Local preference value. This is used to determine the preferred exit point from the local autonomous system. It is propagated throughout the local autonomous system.

weight

Locally assigned weight (if not 0) of the path. Weight is used in choosing the preferred path to a route. It is not advertised to any neighbor.

valid

Path is valid and can be considered in the best-path calculation.

redistributed

Path is redistributed through a redistribute command.

aggregated

Path is a locally generated aggregate created due to an aggregate-address command.

local

Path is a local network source due to a network command.

internal

Path was received from an iBGP neighbor.

external

Path was received from an eBGP neighbor.

atomic-aggregate

Path was received with the atomic-aggregate flag set. Some path information has been removed through aggregation.

best

Path is the best path for the network and is used for routing and advertised to peers.

multipath

Path is a multipath and is installed into the RIB along with the best path.

Community

List of communities attached to the path.

Extended community

List of extended communities attached to the path.

Originator

Originator of the path within the AS Cluster list if the path is reflected.

AS Cluster list

List of RR clusters the path has passed through if the path is reflected

Dampinfo

Penalty and reuse information if the path is dampened.

penalty

Current penalty for the path.

flapped

Number of times the path has flapped and the time since the first flap.

reuse in

Time until the path is re-used (undampened).

half life

Configured half-life for the path.

suppress value

Penalty at which the path is suppressed.

reuse value

Penalty at which the path is re-used.

Maximum suppress time

Maximum length of time for which the path can be suppressed.

The following is sample output from the show bgp command with the ip-address/prefix-length detail options:

RP/0/RSP0/CPU0:router# show bgp 51.0.0.0/24 detail 

Sat Mar 14 00:37:14.109 PST PDT

BGP routing table entry for 51.0.0.0/24

Versions:

  Process           bRIB/RIB  SendTblVer

  Speaker                  3           3

    Flags: 0x3e1000, label_retention: not enabled

Last Modified: Mar 13 19:32:17.976 for 05:04:56

Paths: (1 available, best #1)

  Advertised to update-groups (with more than one peer):

    0.3 0.4 0.7 0.8 

  Advertised to peers (in unique update groups):

    201.48.20.1 

  Path #1: Received by speaker 0

  Flags: 0x1000003

  200 201

    213.0.0.6 from 213.0.0.6 (200.200.3.1)

      Origin IGP, localpref 100, valid, external, best

The following is sample output from the show bgp command with the additional paths received from:

BGP routing table entry for 51.0.1.0/24, Route Distinguisher: 2:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker                 63          63
    Flags: 0x040630f2
Last Modified: Nov 11 12:44:05.811 for 00:00:16
Paths: (3 available, best #2)
  Advertised to CE peers (in unique update groups):
    10.51.0.10 
  Path #1: Received by speaker 0
  Flags: 0x3
  Not advertised to any peer
  111 111 111 111 111 111 111 111
    10.51.0.10 from 10.51.0.10 (11.11.11.11)
      Origin IGP, metric 0, localpref 100, valid, external
      Received Path ID 0, Local Path ID 0, version 0
      Extended community: RT:55:1 
  Path #2: Received by speaker 0
  Flags: 0x5060007
  Advertised to CE peers (in unique update groups):
    10.51.0.10 
  561 562 563 564 565
    13.0.6.50 from 13.0.6.50 (13.0.6.50)
      Received Label 16
      Origin IGP, localpref 100, valid, internal, best, group-best, import-candidate, imported
      Received Path ID 0, Local Path ID 1, version 63
      Extended community: RT:55:1 
  Path #3: Received by speaker 0
  Flags: 0x4060007
  Not advertised to any peer
  591 592 593 594 595
    13.0.9.50 from 13.0.9.50 (13.0.9.50)
      Received Label 16
      Origin IGP, localpref 100, valid, internal, backup, add-path, import-candidate, imported
      Received Path ID 0, Local Path ID 4, version 63
      Extended community: RT:22:232 RT:55:1

This is sample output to explain 'import suspect' state and 'import-suspect' field in show bgp command output:
RP/0/RSP0/CPU0:router#show bgp vpnv4 unicast rd 11:111 100.16.11.0/24
BGP routing table entry for 100.16.11.0/24, Route Distinguisher: 11:111
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker            1834195     1834195
Paths: (2 available, best #1)
  Advertised to update-groups (with more than one peer):
    0.1 
  Path #1: Received by speaker 0
  11
    1:16.16.16.16 (metric 30) from 55.55.55.55 (16.16.16.16)
      Received Label 19602
      Origin incomplete, localpref 100, valid, internal, best, import-candidate, not-in-vrf, import suspect
      Extended community: RT:11:11 
      Originator: 16.16.16.16, Cluster list: 55.55.55.55
  Path #2: Received by speaker 0
  11
    1:16.16.16.16 (metric 30) from 88.88.88.88 (16.16.16.16)
      Received Label 19602
      Origin incomplete, localpref 100, valid, internal, not-in-vrf, import suspect
      Extended community: RT:11:11 
      Originator: 16.16.16.16, Cluster list: 88.88.88.88

The show bgp command output displays 'import suspect' when potential import oscillation has been detected for the prefix. Import of such a prefix is not affected. However, import of the prefix can be dampened in future if the oscillation continues. If the oscillation stops during the next import run, the prefix will no longer be marked 'import supect'.

This is sample output from show bgp vpnv4 unicast rd prefix/length command that displays Accept Own prefix information:
RP/0/RSP0/CPU0:router#show bgp vpnv4 unicast rd 10.10.10.10:1 110.1.1.1/32 detail
BGP routing table entry for 110.1.1.1/32, Route Distinguisher: 10.10.10.10:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker            1412487     1412487
    Local Label: 137742 (no rewrite);
    Flags: 0x04043001+0x00000000;
Last Modified: Jul 19 14:42:43.690 for 00:56:34
Paths: (2 available, best #1)
  Advertised to peers (in unique update groups):
    45.1.1.1
  Path #1: Received by speaker 0
  Flags: 0xd040003, import: 0x1f
  Advertised to peers (in unique update groups):
    45.1.1.1
  101
    10.5.1.2 from 10.5.1.2 (10.5.1.2)
      Origin incomplete, localpref 100, valid, external, best, group-best, import-candidate
      Received Path ID 0, Local Path ID 1, version 1412487
      Extended community: RT:100:1
  Path #2: Received by speaker 0
  Flags: 0x324020005, import: 0x01
  Not advertised to any peer
  101
    15.1.1.1 from 55.1.1.1 (15.1.1.1)
      Received Label 137742
      Origin incomplete, localpref 100, valid, internal, import-candidate, not-in-vrf, accept-own-self
      Received Path ID 0, Local Path ID 0, version 0
      Community: accept-own
      Extended community: RT:100:1 RT:1000:1
      Originator: 15.1.1.1, Cluster list: 55.1.1.1, 75.1.1.1, 45.1.1.1

This is sample output from show bgp vrf vrf-name ipv4unicast prefix/length command that displays Accept Own prefix information on a customer (originating) VRF:
RP/0/RSP0/CPU0:router#show bgp vrf customer1 ipv4 uni 110.1.1.1/32
BGP routing table entry for 110.1.1.1/32, Route Distinguisher: 10.10.10.10:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker            1412487     1412487
    Local Label: 137742
Last Modified: Jul 19 14:42:43.690 for 01:01:22
Paths: (2 available, best #1)
  Advertised to PE peers (in unique update groups):
    45.1.1.1
  Path #1: Received by speaker 0
  Advertised to PE peers (in unique update groups):
    45.1.1.1
  101
    10.5.1.2 from 10.5.1.2 (10.5.1.2)
      Origin incomplete, localpref 100, valid, external, best, group-best, import-candidate
      Received Path ID 0, Local Path ID 1, version 1412487
      Extended community: RT:100:1
  Path #2: Received by speaker 0
  Not advertised to any peer
  101
    15.1.1.1 from 55.1.1.1 (15.1.1.1)
      Received Label 137742
      Origin incomplete, localpref 100, valid, internal, import-candidate, not-in-vrf, accept-own-self
      Received Path ID 0, Local Path ID 0, version 0
      Community: accept-own
      Extended community: RT:100:1 RT:1000:1
      Originator: 15.1.1.1, Cluster list: 55.1.1.1, 75.1.1.1, 45.1.1.1

This is sample output from show bgp vrf vrf-name ipv4unicast prefix/length command that displays Accept Own prefix information on a service VRF:
RP/0/RSP0/CPU0:router#show bgp vrf service1 ipv4 uni 110.1.1.1/32
BGP routing table entry for 110.1.1.1/32, Route Distinguisher: 11.11.11.11:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker            1412497     1412497
Last Modified: Jul 19 14:43:08.690 for 01:39:22
Paths: (1 available, best #1)
  Advertised to CE peers (in unique update groups):
    10.8.1.2
  Path #1: Received by speaker 0
  Advertised to CE peers (in unique update groups):
    10.8.1.2
  101
    10.5.1.2 from 55.1.1.1 (15.1.1.1)
      Origin incomplete, localpref 100, valid, internal, best, group-best, import-candidate, imported, accept-own
      Received Path ID 0, Local Path ID 1, version 1412497
      Community: accept-own
      Extended community: RT:100:1 RT:1000:1
      Originator: 15.1.1.1, Cluster list: 55.1.1.1, 75.1.1.1, 45.1.1.1

This table describes the significant fields shown in the display:
Field Description

accept-own-self

The Accept Own path in the customer VRF contains the "accept-own-self" keyword/flag.

accept-own

The Accept Own path contains the "accept-own" keyword/flag.

Community:accept-own

List of communities attached to the path: accept-own.

Extended community

List of extended communities attached to the path.

Cluster list

Router ID or cluster ID of all route reflectors through which the route has passed.

The output of show bgp {vpnv4 | vpnv6} unicast rd command may display the optional BGP attribute not-in-vrf. If a path in a VPNvX net is marked as not-in-vrf, it may be due to any of the following conditions:
  • The RD of the VPNvX net is not the same as any of the RDs configured for VRFs on the router.
  • The RD of the VPNvX net is the same as the RD configured for a specific VRF on the router, but the path is not imported to the specified VRF. For example, the route-targets attached to the path do not match any of the import route-target [as-number:nn | ip-address:nn] configured for VRF, vrf_1.

If the not-in-vrf net is set, it indicates that the path does not belong to the VRF.

Related Commands

Command

Description

aggregate-address

Creates an aggregate entry in a BGP routing table.

bgp default local-preference

Changes the default local preference value.

network (BGP)

Specifies a local network that the BGP routing process should originate and advertise to its neighbors.

route-policy (BGP)

Applies a routing policy to updates advertised to or received from a BGP neighbor.

set default-afi

Sets the default Address Family Identifier (AFI) for the current session.

set default-safi

Sets the default subaddress Family Identifier (SAFI) for the current session.

show bgp cidr-only

Displays routes with nonnatural netmasks.

show bgp community

Displays routes belonging to the specified communities.

show bgp inconsistent-as

Displays networks with inconsistent origin autonomous system.

show bgp regexp

Displays routes matching an AS path regular expression.

show bgp route-policy

Displays networks that match a route policy.

show bgp summary

Displays the status of all BGP connections.

show bgp truncated-communities

Displays networks with community lists truncated by policy.

show bgp advertised

To display advertisements for neighbors or a single neighbor, use the show bgp advertisedcommand in EXEC mode.

show bgp [ ipv4 { all | labeled-unicast | multicast | tunnel | unicast } ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

show bgp [ ipv6 { all | labeled-unicast | multicast | unicast } ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

show bgp [ all { all | labeled-unicast | multicast | tunnel | unicast } ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

show bgp [ vpnv4 unicast [ rd rd-address ] ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

show bgp [ vpnv6 unicast [ rd rd-address ] ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

show bgp [ vrf { vrf-name | all } [ ipv4 | { labeled-unicast | unicast } | ipv6 unicast ] ] advertised [ neighbor ip-address ] [ standby ] [ summary ]

Syntax Description

ipv4

(Optional) Specifies IP Version 4 address prefixes.

unicast

(Optional) Specifies unicast address prefixes.

multicast

(Optional) Specifies multicast address prefixes.

labeled-unicast

(Optional) Specifies labeled unicast address prefixes.

all

(Optional) For address family, specifies prefixes for all address families.

tunnel

(Optional) Specifies tunnel address prefixes.

ipv6

(Optional) Specifies IP Version 6 address prefixes.

vpnv4 unicast

(Optional) Specifies VPNv4 unicast address families.

rd rd-address

(Optional) Displays routes with a specific route distinguisher.

vrf

(Optional) Specifies VPN routing and forwarding (VRF) instance.

vrf-name

(Optional) Name of a VRF.

all

(Optional) For VRF, specifies all VRFs.

ipv4 { unicast | labeled-unicast }

(Optional) For VRF, specifies IPv4 unicast or labeled-unicast address families.

ipv6 unicast

(Optional) For VRF, specifies IPv6 unicast address families.

neighbor

(Optional) Previews advertisements for a single neighbor. If the neighbor keyword is omitted, then the advertisements for all neighbors are displayed.

ip-address

(Optional) IP address of the neighbor.

summary

(Optional) Displays a summary of advertisements.

Command Default

If no address family or subaddress family is specified, the default address family and subaddress family specified using the set default-afi and set default-safi commands are used.

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines


Note


The set default-afi command is used to specify the default address family for the session, and the set default-safi command is used to specify the default subaddress family for the session. See the Cisco ASR 9000 Series Aggregation Services Router System Management Command Reference for detailed information and syntax for the set default-afi and set default-safi commands. If you do not specify a default address family, the default address family is IPv4. If you do not specify a default subaddress family, the default subaddress family is unicast.


BGP contains a separate routing table for each address family and subaddress family combination that is configured. The address family and subaddress family options specify the routing table to be examined. If the all keyword is specified for the address family or subaddress family, each matching routing table is examined in turn.

Use the show bgp advertised command to display the routes that have been advertised to peers or a specific peer. To preview advertisements that would be sent to a peer under a particular policy, even if the corresponding update messages have not been generated yet, use the show bgp policy command.


Note


When you issue the show bgp advertised command, a route is not displayed in the output unless an advertisement for that route has already been sent (and not withdrawn). If an advertisement for the route has not yet been sent, the route is not displayed.


Use the summary keyword to display a summary of the advertised routes. If you do not specify the summary keyword, the software displays detailed information about the advertised routes.


Note


The show bgp advertised command does not display the application of any outbound policy in the route details it displays. Consequently, this command provides only an indication of whether a particular route has been advertised, rather than details of which attributes were advertised. Use the show bgp policy sent-advertisements command to display the attributes that are advertised.


Task ID

Task ID

Operations

bgp

read

Examples

The following is sample output from the show bgp advertised command in EXEC mode:

RP/0/RSP0/CPU0:router# show bgp advertised neighbor 10.0.101.4 summary 

Network     Next Hop            From          AS Path
1.1.1.0/24  10.0.101.1          10.0.101.1    2 3 222 333 444 555 i
1.1.2.0/24  10.0.101.1          10.0.101.1    3 4 5 6 7 i
1.1.3.0/24  10.0.101.1          10.0.101.1    77 88 33 44 55 99 99 99 i
1.1.4.0/24  10.0.101.1          10.0.101.1    2 5 6 7 8 i
1.1.7.0/24  10.0.101.1          10.0.101.1    3 5 i
1.1.8.0/24  10.0.101.1          10.0.101.1    77 88 99 99 99 i

This table describes the significant fields shown in the display.

Table 5 show bgp advertised neighbor summary Field Descriptions

Field

Description

Network

IP prefix and prefix length for a network.

Next Hop

IP address of the next system that is used when a packet is forwarded to the destination network. An entry of 0.0.0.0 indicates that the router has a non-BGP route to this network.

From

IP address of the peer that advertised this route.

AS Path

AS path of the peer that advertised this route.

Local

Indicates the route originated on the local system.

Local Aggregate

Indicates the route is an aggregate created on the local system.

Advertised to

Indicates the peer to which this entry was advertised. This field is used in the output when displaying a summary of the advertisements to all neighbors.

The following is sample output from the show bgp advertised command for detailed advertisement information:

RP/0/RSP0/CPU0:router# show bgp advertised neighbor 172.72.77.1

172.16.0.0/24 is advertised to 172.72.77.1
  Path info:
    neighbor: Local            neighbor router id: 172.74.84.1
    valid  redistributed  best  
  Attributes after inbound policy was applied:
 next hop: 0.0.0.0
    MET ORG AS 
    origin: incomplete  metric: 0  
    aspath:
10.52.0.0/16 is advertised to 172.72.77.1
  Path info:
    neighbor: Local Aggregate  neighbor router id: 172.74.84.1
    valid  aggregated  best  
  Attributes after inbound policy was applied:
 next hop: 0.0.0.0
    ORG AGG ATOM 
    origin: IGP  aggregator: 172.74.84.1 (1)  
    aspath:

This table describes the significant fields shown in the display.

Table 6 show bgp advertised neighbor Field Descriptions

Field

Description

is advertised to

IP address of the peer to which this route has been advertised. If the route has been advertised to multiple peers, the information is shown separately for each peer.

neighbor

IP address of the peer that advertised this route, or one of the following:

Local—Route originated on the local system.

Local Aggregate—Route is an aggregate created on the local system.

neighbor router id