Cisco IOS IP Routing: BGP Command Reference

clear bgp l2vpn evpn

To reset Border Gateway Protocol (BGP) neighbor session information for Layer 2 Virtual Private Network (L2VPN) address family Ethernet VPN, use the clear bgp l2vpn evpn command in privileged EXEC mode.

clear bgp l2vpn evpn {* | as-number | ip-address [cease | flap-statistics] | external | internal | peer-group peer-group-name | update-group [number | ipv4-address | ipv6-address]} [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description


*	Specifies that all current BGP sessions will be reset.
`as-number`	Autonomous system number for which to clear and then reset BGP sessions for BGP neighbors. The range is from 1 to 4294967295.
`ip-address`	IP address of the BGP neighbor for which to clear the TCP connection and remove all routes learned from the connection from the BGP table.
cease	(Optional) Sends cease notification to the BGP neighbor.
flap-statistics	(Optional) Clears flap statistics for the BGP neighbor.
external	Clears all external BGP (eBGP) peers.
internal	Clears all BGP internal statistics counters.
peer-group `peer-group-name`	Clears the identified BGP peer group.
update-group	Clears the identified BGP update group.
`number`	(Optional) Update group number for which to clear update group session information.
`ipv4-address`	(Optional) IPv4 address for which to clear update group session information for the BGP peer.
`ipv6-address`	(Optional) IPv6 address for which to clear update group session information for the BGP peer.
in	(Optional) Initiates inbound reconfiguration. If neither the in keyword nor out keyword is specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in keyword nor out keyword is specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
15.4(1)S	This command was introduced.
Cisco IOS XE Release 3.11S	This command was integrated into Cisco IOS XE Release 3.11S.

Usage Guidelines

The clear bgp l2vpn evpn command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

The following example configures soft reconfiguration for the inbound session with BGP L2VPN peers in the 45000 autonomous system. The outbound session is unaffected:

Router# clear bgp l2vpn evpn 45000 soft in

Related Commands


Command	Description
address-family l2vpn	Enters address family configuration mode to configure a routing session using L2VPN endpoint provisioning information.
clear ip bgp l2vpn	Resets BGP neighbor session information for L2VPN address family.
neighborsoft-reconfiguration	Configures the Cisco IOS software to start storing updates.

clear bgp nsap

To clear and then reset Connectionless Network Service (CLNS) network service access point (NSAP) Border Gateway Protocol (BGP) sessions, use the clear bgp nsap command in privileged EXEC mode.

clear bgp nsap {* | as-number | ip-address} [soft] [in | out]

Syntax Description


*	Clears and then resets all current BGP sessions.
`as-number`	Clears and then resets BGP sessions for BGP neighbors within the specified autonomous system.
`ip-address`	Clears the TCP connection to the specified BGP neighbor and removes all routes learned from the connection from the BGP table. The TCP connections are then reset.
soft	(Optional) Soft reset. Allows routing tables to be reconfigured and activated without clearing the BGP session.
in \| out	(Optional) Triggers inbound or outbound soft reconfiguration. If the in or out option is not specified, both inbound and outbound soft reset are triggered.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(8)T	This command was introduced.
12.2(33)SRB	This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE 2.6	This command was integrated into Cisco IOS XE Release 2.6.

Usage Guidelines

The clear bgp nsap command is similar to the clear ip bgp command, except that it is NSAP address family-specific.

Use of the clear bgp nsap command allows a reset of the neighbor sessions with varying degrees of severity, depending on the specified keywords and arguments.

Use the * keyword to reset all neighbor sessions. The software will clear and then reset the neighbor connections. Use this form of the command in the following situations:

BGP timer specification change
BGP administrative distance changes

Use the soft out keywords to clear and reset only the outbound neighbor connections. Inbound neighbor sessions will not be reset. Use this form of the command in the following situations:

Additions or changes are made to the BGP-related access lists
BGP-related weights change
BGP-related distribution lists change
BGP-related route maps change

Use the in keyword to clear only the inbound neighbor connections. Outbound neighbor sessions will not be reset. Use this form of the command in the following situations:

BGP-related access lists change or get additions
BGP-related weights change
BGP-related distribution lists change
BGP-related route maps change

Examples

In the following example, the inbound session with the neighbor 172.20.16.6 is cleared without the outbound session being reset:


Router# clear bgp nsap 172.20.16.6 in

In the following example, a soft clear is applied to outbound sessions with the neighbors in autonomous system 65000 without the inbound session being reset:


Router# clear bgp nsap 65000 soft out

Related Commands


Command	Description
show bgp nsap	Displays entries in the BGP routing table for the NSAP address family.

clear bgp nsap dampening

To clear Border Gateway Protocol (BGP) route dampening information for the network service access point (NSAP) address family and unsuppress the suppressed routes, use the clear bgp nsap dampening command in privileged EXEC mode.

clear bgp nsap dampening [nsap-prefix]

Syntax Description


`nsap-prefix`	(Optional) NSAP prefix about which to clear dampening information. This argument can be up to 20 octets long.

Command Default

When the nsap-prefix argument is not specified, the clear bgp nsap dampening command clears route dampening information for the entire BGP routing table for the NSAP address family.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(8)T	This command was introduced.
12.2(33)SRB	This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE 2.6	This command was integrated into Cisco IOS XE Release 2.6.

Usage Guidelines

The clear bgp nsap dampening command is similar to the clear ip bgp dampening command, except that it is specific to the NSAP address family.

Examples

In the following example, route dampening information is cleared for the route to NSAP prefix 49.6001 and locally suppressed routes are unsuppressed:


Router# clear bgp nsap dampening 49.6001

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or changes various BGP route dampening factors.
show bgp nsap dampened-paths	Displays BGP dampened routes for the NSAP address family.

clear bgp nsap external

To clear all external BGP (eBGP) peers for the network service access point (NSAP) address family, use the clear bgp nsap external command in privileged EXEC mode.

clear bgp nsap external [soft] [in | out]

Syntax Description


soft	(Optional) Soft reset. Does not reset the session.
in \| out	(Optional) Triggers inbound or outbound soft reconfiguration. If the in or out option is not specified, both inbound and outbound soft reset are triggered.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(8)T	This command was introduced.
12.2(33)SRB	This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE 2.6	This command was integrated into Cisco IOS XE Release 2.6.

Usage Guidelines

The clear bgp nsap external command is similar to the clear ip bgp external command, except that it is specific to the NSAP address family.

Examples

In the following example, the inbound sessions with external BGP peers are cleared without the outbound sessions being reset:


Router# clear bgp nsap external soft in

Related Commands


Command	Description
clear bgp nsap	Resets an NSAP BGP connection by dropping all neighbor sessions.

clear bgp nsap flap-statistics

To clear Border Gateway Protocol (BGP) flap statistics for the network service access point (NSAP) address family, use the clear bgp nsap flap-statistics command in privileged EXEC mode.

clear bgp nsap flap-statistics [nsap-prefix] [regexp regexp | filter-list access-list-number]

Syntax Description


`nsap-prefix`	(Optional) NSAP prefix about which to clear dampening information. This argument can be up to 20 octets long.
regexp `regexp`	(Optional) Clears flap statistics for all the paths that match the regular expression.
filter-list `access-list-number`	(Optional) Clears flap statistics for all the paths that pass the access list. The acceptable access list number range is from 1 to 199.

Command Default

No statistics are cleared.

If no arguments or keywords are specified, the software clears flap statistics for all routes.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(8)T	This command was introduced.
12.2(33)SRB	This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE 2.6	This command was integrated into Cisco IOS XE Release 2.6.

Usage Guidelines

The clear bgp nsap flap-statistics command is similar to the clear ip bgp flap-statistics command, except that it is specific to the NSAP address family.

The flap statistics for a route are also cleared when an NSAP BGP peer is reset. Although the reset withdraws the route, no penalty is applied in this instance even though route flap dampening is enabled.

Examples

In the following example, all of the flap statistics for paths that pass access list 3 are cleared:


Router# clear bgp nsap flap-statistics filter-list 3

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or changes various BGP route dampening factors.
show bgp nsap flap-statistics	Displays BGP flap statistics for the NSAP address family.

clear bgp nsap peer-group

To clear the Border Gateway Protocol (BGP) TCP connections to all members of a BGP peer group for the network service access point (NSAP) address family, use the clear bgp nsap peer-group command in privileged EXEC mode.

clear bgp nsap peer-group peer-group-name

Syntax Description


`peer-group-name`	Name of the NSAP BGP peer group.

Command Default

No BGP TCP connections are cleared.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(8)T	This command was introduced.
12.2(33)SRB	This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE 2.6	This command was integrated into Cisco IOS XE Release 2.6.

Usage Guidelines

The clear bgp nsap peer-group command is similar to the clear ip bgp peer-group command, except that it is specific to the NSAP address family.

Examples

In the following example, the BGP TCP connections are cleared for all members of the NSAP BGP peer group named internal:


Router# clear bgp nsap peer-group internal

Related Commands


Command	Description
neighbor peer-group (assigning members)	Configures a BGP neighbor to be a member of a peer group.

clear proximity ip bgp

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration, use the clear proximity ip bgp command in privileged EXEC mode.

clear proximity ip bgp {* | all | autonomous-system-number | neighbor-address | peer-group group-name} [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description


*	Specifies that all current BGP sessions will be reset.
all	(Optional) Specifies the reset of all address family sessions.
`autonomous-system-number`	Number of the autonomous system in which all BGP peer sessions will be reset. Number in the range from 1 to 65535. In Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, and later releases, 4-byte autonomous system numbers are supported in the range from 65536 to 4294967295 in asplain notation and in the range from 1.0 to 65535.65535 in asdot notation. In Cisco IOS Release 12.0(32)S12, 12.4(24)T, and Cisco IOS XE Release 2.3, 4-byte autonomous system numbers are supported in the range from 1.0 to 65535.65535 in asdot notation only. For more details about autonomous system number formats, see the router bgp command.
`neighbor-address`	Specifies that only the identified BGP neighbor will be reset. The value for this argument can be an IPv4 or IPv6 address.
peer-group `group-name`	Specifies that only the identified BGP peer group will be reset.
in	(Optional) Initiates inbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
10.0	This command was introduced.
12.0(2)S	This command was integrated into Cisco IOS Release 12.0(2)S, and dynamic inbound soft reset capability was added.
12.0(7)T	The dynamic inbound soft reset capability was integrated into Cisco IOS Release 12.0(7)T.
12.0(22)S	The vpnv4 and ipv4 keywords were added.
12.0(29)S	The mdt keyword was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(14)SX	This command was integrated into Cisco IOS Release 12.2(14)SX.
12.0(32)S12	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.0(32)SY8	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.4(24)T	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
Cisco IOS XE Release 2.3	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.2(33)SXI1	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.0(33)S3	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
Cisco IOS XE Release 2.4	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
15.0(1)S	This command was modified. The slow keyword was added.
Cisco IOS XE 3.1S	This command was modified. The slow keyword was added.
15.2(1)E	This command was integrated into Cisco IOS Release 15.2(1)E.
15.2(1)S	This command was modified. The proximity keyword was added.

Usage Guidelines

Theclearproximity ip bgp command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Note

Due to the complexity of some of the keywords available for the clear proximityip bgp command, some of the keywords are documented as separate commands. All of the complex keywords that are documented separately start with clear ip bgp . For example, for information on resetting BGP connections using hard or soft reconfiguration for all BGP neighbors in IPv4 address family sessions, refer to the clear ip bgp ipv4 command.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear proximityip bgp command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound session with the neighbor 10.100.0.1, and the outbound session is unaffected:


Device#
 clear proximity ip bgp 10.100.0.1 soft in

In the following example, the route refresh capability is enabled on the BGP neighbor routers and a soft reconfiguration is initiated for the inbound session with the neighbor 172.16.10.2, and the outbound session is unaffected:


Device#
 clear proximity ip bgp 172.16.10.2 in

In the following example, a hard reset is initiated for sessions with all routers in the autonomous system numbered 35700:


Device#
 clear proximity ip bgp 35700

In the following example, a hard reset is initiated for sessions with all routers in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.


Device#
 clear proximity ip bgp 65538

In the following example, a hard reset is initiated for sessions with all routers in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.


Device#
 clear proximity ip bgp 1.2

Related Commands


Command	Description
bgp slow-peer split-update-group dynamic permanent	Moves a dynamically detected slow peer to a slow update group.
clear ip bgp ipv4	Resets BGP connections using hard or soft reconfiguration for IPv4 address family sessions.
clear ip bgp ipv6	Resets BGP connections using hard or soft reconfiguration for IPv6 address family sessions.
clear ip bgp vpnv4	Resets BGP connections using hard or soft reconfiguration for VPNv4 address family sessions.
clear ip bgp vpnv6	Resets BGP connections using hard or soft reconfiguration for VPNv6 address family sessions.
neighbor slow-peer split-update-group dynamic permanent	Moves a dynamically detected slow peer to a slow update group.
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
router bgp	Configures the BGP routing process.
show ip bgp	Displays entries in the BGP routing table.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.
slow-peer split-update-group dynamic permanent	Moves a dynamically detected slow peer to a slow update group.

clear ip bgp dampening

To clear BGP route dampening information and to unsuppress suppressed routes, use the clear ip bgp dampening command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] dampening [network-address] [ipv4-mask]

Syntax With Address Family Syntax

clear ip bgp [ipv4 {multicast | unicast}] dampening [network-address] [ipv4-mask]

clear ip bgp [vrf vrf-name] [vpnv4 unicast] dampening [rd route-distinguisher] [network-address] [ipv4-mask]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
`network-address`	(Optional) IPv4 address of the network or neighbor to clear dampening information. If no address family keyword is specified when entering the `neighbor-address` argument, you will be prompted for an IPv4 address.
`ipv4-mask`	(Optional) IPv4 network mask.
ipv4	(Optional) Specifies the reset of IPv4 address family sessions.
multicast	(Optional) Specifies multicast address family sessions.
unicast	(Optional) Specifies unicast address family sessions.
vpn4	(Optional) Specifies the reset of Virtual Private Network Version 4 (VPNv4) address family sessions.
rd `route-distinguisher`	(Optional) Specifies the VPN route distinguisher.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
11.0	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp dampening is used to clear stored route dampening information. If no keywords or arguments are entered, route dampening information for the entire routing table is cleared.

Examples

The following example clears route dampening information for VPNv4 address family prefixes from network 192.168.10.0/24 and unsuppress suppressed routes.


Router#
 clear ip bgp vpnv4 unicast dampening 192.168.10.0 255.255.255.0

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or configures BGP route dampening parameters.
clear ip bgp flap-statistics	Resets BGP route dampening flap-statistics.
set dampening	Sets set BGP route dampening parameters in a route map.
show ip bgp dampened-paths	Displays BGP dampened routes.

clear ip bgp external

To reset external Border Gateway Protocol (eBGP) peering sessions using hard or soft reconfiguration, use the clear ip bgp external command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp external [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax With Address Family Syntax

clear ip bgp external [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax Description


in	(Optional) Initiates inbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
soft	(Optional) Initiates a soft reset. Does not tear down the session.
all	(Optional) Specifies the reset of eBGP peering sessions for all address families.
ipv4	(Optional) Specifies the reset of eBGP peering sessions for IPv4 address family sessions.
multicast	(Optional) Specifies multicast address family sessions.
mdt	(Optional) Specifies multicast distribution tree (MDT) address family sessions.
unicast	(Optional) Specifies unicast address family sessions.
ipv6	(Optional) Specifies the reset of eBGP peering sessions for IPv6 address family sessions.
vpnv4	(Optional) Specifies the reset of eBGP peering sessions for Virtual Private Network Version 4 (VPNv4) address family sessions.
vpnv6	(Optional) Specifies the reset of eBGP peering sessions for Virtual Private Network Version 6 (VPNv6) address family sessions.

Command Modes

Privileged EXEC

Command History


Release	Modification
12.0(2)S	This command was introduced.
12.0(22)S	The vpnv4 and ipv4 keywords were added.
12.0(29)S	The mdt keyword was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.

Usage Guidelines

The clear ip bgp external command can be used to initiate a hard reset or soft reconfiguration of eBGP neighbor sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is configured for all inbound eBGP peering sessions:


Router# clear ip bgp external soft in

In the following example, all outbound address family IPv4 multicast eBGP peering sessions are cleared:


Router# clear ip bgp external ipv4 multicast out

Related Commands


Command	Description
clear ip bgp	Resets BGP connections using hard or soft reconfiguration.
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp flap-statistics

To clear BGP route dampening flap statistics, use the clear ip bgp flap-statistics command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] flap-statistics [neighbor-address [ipv4-mask] | regexp regexp | filter-list extcom-number]

Syntax With Address Family Syntax

clear ip bgp [neighbor-address] [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] flap-statistics

Syntax Description


`neighbor-address`	(Optional) Clears flap statistics for the specified IP address. If this argument is placed before flap-statistics keyword, the router clears flap statistics for all paths from the specified neighbor or network. The value for this argument can be an IPv4 or IPv6 address.
vrf	(Optional) Specifies an instance of a routing table.
vrf-name	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
`ipv4-mask`	(Optional) IPv4 network mask.
regexp	(Optional) Clears flap statistics for all the paths that match the regular expression.
`regexp`	(Optional) Regular expression.
filter-list	(Optional) Clears flap statistics for all the paths that pass the access list. The access list is specified using an extended community list number.
`extcom-number`	(Optional) Extended community list number.
all	(Optional) Clears flap statistics for all address family sessions.
ipv4	(Optional) Clears flap statistics for IPv4 address family sessions.
multicast	(Optional) Clears flap statistics for multicast address family sessions.
mdt	(Optional) Clears flap statistics for multicast distribution tree (MDT) address family sessions.
unicast	(Optional) Clears flap statistics for unicast address family sessions.
ipv6	(Optional) Clears flap statistics for IPv6 address family sessions.
vpnv4	(Optional) Clears flap statistics for Virtual Private Network Version 4 (VPNv4) address family sessions.
vpnv6	(Optional) Clears flap statistics for Virtual Private Network Version 6 (VPNv6) address family sessions.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
11.0	This command was introduced.
12.0(22)S	The vpnv4 and ipv4 keywords were added.
12.0(29)S	The mdt keyword was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp flap-statistics command is used to clear the accumulated penalty for routes that are received on a router that has BGP dampening enabled. If no arguments or keywords are specified, flap statistics are cleared for all routes. Flap statistics are also cleared when the peer is stable for the half-life time period.

Examples

In the following example, all of the flap statistics are cleared for paths that pass filter list 3:


Router#
 clear ip bgp flap-statistics filter-list 3

In the following example, all of the flap statistics are cleared for the paths to the BGP neighbor at 10.2.1.3:


Router#
 clear ip bgp 10.2.1.3 flap-statistics

In the following example, all of the flap statistics are cleared for the paths to the BGP neighbor at 10.2.1.3 under IPv4 multicast address family:


Router#
 clear ip bgp 10.2.1.3 ipv4 multicast flap-statistics

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or changes various BGP route dampening factors.
clear ip bgp dampening	Clears BGP route dampening information and to unsuppress suppressed routes.
set dampening	Sets set BGP route dampening parameters in a route map.
show ip bgp dampened-paths	Displays BGP dampened routes.

clear ip bgp in prefix-filter

The in and prefix-filter keywords for the clear ip bgp command are no longer documented as a separate command.

The information for using the in and prefix-filter keywords with the clear ip bgp command has been incorporated into all the appropriate clear ip bgp command documentation. Due to the complexity of some of the keywords available for the clear ip bgp command, some of the keywords are documented as separate commands. All of the complex keywords that are documented separately start with clear ip bgp . For example, for information on resetting BGP connections using hard or soft reconfiguration for all BGP neighbors in IPv4 address family sessions, refer to the clear ip bgp ipv4 command.

clear ip bgp ipv4

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv4 address family sessions, use the clear ip bgp ipv4 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] ipv4 {multicast | mdt | unicast} autonomous-system-number [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
vrf-name	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
multicast	Resets multicast address family sessions.
mdt	Resets multicast distribution tree (MDT) address family sessions.
unicast	Resets unicast address family sessions.
`autonomous-system-number`	Resets BGP peers with the specified autonomous system number. Number in the range from 1 to 65535. In Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, and later releases, 4-byte autonomous system numbers are supported in the range from 65536 to 4294967295 in asplain notation and in the range from 1.0 to 65535.65535 in asdot notation. In Cisco IOS Release 12.0(32)S12, 12.4(24)T, and Cisco IOS XE Release 2.3, 4-byte autonomous system numbers are supported in the range from 1.0 to 65535.65535 in asdot notation only. For more details about autonomous system number formats, see the router bgp command.
in	(Optional) Initiates inbound reconfiguration. If neither the in keyword nor the out keyword is specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates outbound reconfiguration. If neither the in keyword nor the out keyword is specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.0(22)S	This command was introduced.
12.0(29)S	The mdt keyword was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(31)SB2	This command was integrated into Cisco IOS Release 12.2(31)SB2.
12.2(14)SX	This command was integrated into Cisco IOS Release 12.2(14)SX.
12.4(20)T	This command was modified. The mdt keyword was added.
12.0(32)S12	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.0(32)SY8	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.4(24)T	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
Cisco IOS XE Release 2.3	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.2(33)SXI1	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.0(33)S3	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
Cisco IOS XE Release 2.4	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp ipv4 command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically generating inbound updates) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for nondisruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp ipv4 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in IPv4 unicast address family sessions in autonomous system 65400, and the outbound session is unaffected:


Router#
 clear ip bgp ipv4 unicast 65400 soft in

In the following example, the route refresh capability is enabled on the IPv4 multicast address family BGP neighbors in autonomous system 65000, a soft reconfiguration is initiated for all inbound sessions with the IPv4 multicast address family neighbors, and the outbound session is unaffected:


Router#
 clear ip bgp ipv4 multicast 65000 in

In the following example, a hard reset is initiated for all BGP neighbor in IPv4 MDT address family sessions in the autonomous system numbered 65400:


Router#
 clear ip bgp ipv4 mdt 65400

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.


Router#
 clear ip bgp ipv4 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.


Router#
 clear ip bgp ipv4 unicast 1.2

Related Commands


Command	Description
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
router bgp	Configures the BGP routing process.
show ip bgp ipv4	Displays entries in the IPv4 BGP routing table.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp ipv6

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv6 address family sessions, use the clear ip bgp ipv6 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] ipv6 {multicast | unicast} autonomous-system-number [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
multicast	(Optional) Specifies the reset of multicast address family sessions.
unicast	(Optional) Specifies the reset of unicast address family sessions.
`autonomous-system-number`	Specifies that sessions with BGP peers in the specified autonomous system will be reset. Number in the range from 1 to 65535. In Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, and later releases, 4-byte autonomous system numbers are supported in the range from 65536 to 4294967295 in asplain notation and in the range from 1.0 to 65535.65535 in asdot notation. In Cisco IOS Release 12.0(32)S12, 12.4(24)T, and Cisco IOS XE Release 2.3, 4-byte autonomous system numbers are supported in the range from 1.0 to 65535.65535 in asdot notation only. For more details about autonomous system number formats, see the router bgp command.
in	(Optional) Initiates inbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(2)T	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(14)SX	This command was integrated into Cisco IOS Release 12.2(14)SX.
12.0(32)S12	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.0(32)SY8	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.4(24)T	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
Cisco IOS XE Release 2.3	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.2(33)SXI1	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.0(33)S3	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
Cisco IOS XE Release 2.4	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp ipv6 command can be used to initiate a hard reset or soft reconfiguration of IPv6 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp ipv6 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in IPv6 unicast address family sessions, and the outbound session is unaffected:


Router#
 clear ip bgp ipv6 unicast soft in

In the following example, the route refresh capability is enabled on the IPv6 multicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the IPv6 multicast address family neighbors, and the outbound session is unaffected:


Router#
 clear ip bgp ipv6 multicast in

In the following example, a hard reset is initiated for neighbor sessions with all IPv6 unicast address family routers in the autonomous system numbered 35400:


Router#
 clear ip bgp ipv6 unicast 35400

In the following example, a hard reset is initiated for BGP neighbors in IPv6 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.


Router#
 clear ip bgp ipv6 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv6 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.


Router#
 clear ip bgp ipv6 unicast 1.2

Related Commands


Command	Description
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
router bgp	Configures the BGP routing process.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp l2vpn

To reset Border Gateway Protocol (BGP) neighbor session information for Layer 2 Virtual Private Network (L2VPN) address family, use the clear ip bgp l2vpn command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] l2vpn vpls {autonomous-system-number | peer-group peer-group-name | update-group [number | ip-address]} [in [prefix-filter] | out | slow | soft [in [prefix-filter] | out | slow]]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
vpls	Specifies that Virtual Private LAN Service (VPLS) subsequent address family identifier (SAFI) information will be cleared.
`autonomous-system- number`	Autonomous system number in which peers are reset.
peer-group `peer-group-name`	Clears peer group information for the peer group specified with the `peer-group-name` argument.
update-group	Clears update group session information.
`number`	(Optional) Clears update-group session information for the specified update group number.
`ip-address`	(Optional) Clears update-group session information for the peer specified with the `ip-address` argument.
in	(Optional) Initiates inbound reconfiguration. If neither the in keyword nor out keyword is specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the inbound prefix filter.
out	(Optional) Initiates outbound reconfiguration. If neither the in keyword nor out keyword is specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Default

If no arguments or keywords are specified, all BGP L2VPN VPLS neighbor session information is cleared.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(33)SRB	This command was introduced.
Cisco IOS XE Release 2.4	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp l2vpn command clears BGP session information for the L2VPN address family and VPLS SAFI. This command can be used to initiate a hard reset or soft reconfiguration. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use the clear ip bgp l2vpn command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp l2vpn vpls {autonomous-system-number | peer-group peer-group-name | update-group [number | ip-address ]} in command. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After a soft reset (inbound or outbound) is configured, it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router memory pool.

Examples

The following example configures soft reconfiguration for the inbound session with BGP L2VPN peers in the 45000 autonomous system. The outbound session is unaffected:


Router#
 clear ip bgp l2vpn vpls 45000 soft in

Related Commands


Command	Description
address-family l2vpn	Enters address family configuration mode to configure a routing session using L2VPN endpoint provisioning information.
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.

clear ip bgp mvpn

To clear Border Gateway Protocol (BGP) route dampening information with multicast VPN (MVPN) address family sessions and to unsuppress suppressed routes, use the clear ip bgp mvpn command in privileged EXEC mode.

clear ip bgp {ipv4|ipv6} mvpn vrf vrf-name {dampening|flap-statistics}

Syntax Description


ipv4	Specifies the reset of IPv4 address family sessions.
ipv6	Specifies the reset of IPv6 address family sessions.
vrf `vrf-name`	Specifies the name of the VPN routing and forwarding (VRF) instance.
dampening	Clears multicast VPN BGP dampening information.
flap-statistics	Clears multicast VPN BGP dampening flap statistics.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Release 3.8S	This command was introduced.

Usage Guidelines

The clear ip bgp mvpn command is used to clear stored route dampening information for multicast VPN BGP dampening. You must specify a VRF instance using the vrf vrf-name keyword and argument prior to clearing either the dampening information (using the dampening keyword) or the flap statistics (using the flap-statistics keyword).

Examples

The following example clears route dampening information for IPv4 MVPN address family prefixes (VRF named blue) and unsuppresses suppressed routes.


Device# clear ip bgp ipv4 mvpn vrf blue dampening

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or configures BGP route dampening parameters.
show bgp mvpn	Resets BGP route dampening flap statistics.

clear ip bgp peer-group

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for all the members of a BGP peer group, use the clear ip bgp peer-group command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] peer-group peer-group-name [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax With Address Family Syntax

clear ip bgp [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] peer-group peer-group-name [in [prefix-filter]] [out] [soft [in [prefix-filter] | out]]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
`peer-group-name`	Peer group name.
in	(Optional) Initiates inbound reconfiguration. If neither the in keyword nor the out keyword is specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates outbound reconfiguration. If neither the in keyword nor the out keyword is specified, both inbound and outbound sessions are reset.
soft	(Optional) Initiates a soft reset. Does not tear down the session.
all	(Optional) Specifies the reset of peer group members in all address families.
ipv4	(Optional) Specifies the reset of peer group members in IPv4 address family sessions.
multicast	(Optional) Specifies the reset of peer group members in multicast address family sessions.
mdt	(Optional) Specifies the reset of peer group members in multicast distribution tree (MDT) address family sessions.
unicast	(Optional) Specifies the reset of peer group members in unicast address family sessions.
ipv6	(Optional) Specifies the reset of peer group members in IPv6 address family sessions.
vpnv4	(Optional) Specifies the reset of peer group members in Virtual Private Network Version 4 (VPNv4) address family sessions.
vpnv6	(Optional) Specifies the reset of peer group members in Virtual Private Network Version 6 (VPNv6) address family sessions.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
11.0	This command was introduced.
12.0(2)S	This command was integrated into Cisco IOS Release 12.0(2)S, and dynamic inbound soft reset capability was added.
12.0(7)T	The dynamic inbound soft reset capability was integrated into Cisco IOS Release 12.0(7)T.
12.0(22)S	The vpnv4 and ipv4 keywords were added.
12.0(29)S	The mdt keyword was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(31)SB2	This command was integrated into Cisco IOS Release 12.2(31)SB2.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp peer-group command is used to initiate a hard reset or soft reconfiguration for neighbor sessions for BGP peer groups. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically generating inbound updates) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for nondisruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp peer-group command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of the routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, all members of the BGP peer group named INTERNAL are reset:


Router#
 clear ip bgp peer-group INTERNAL

In the following example, members of the peer group named EXTERNAL in IPv4 multicast address family sessions are reset:


Router#
 clear ip bgp ipv4 multicast peer-group EXTERNAL

In the following example, a soft reconfiguration is initiated for the inbound session with members of the peer group INTERNAL, and the outbound session is unaffected:


Router#
 clear ip bgp peer-group INTERNAL soft in

Related Commands


Command	Description
clear ip bgp	Resets a BGP connection or session.
neighbor peer-group (assigning members)	Configures a BGP neighbor to be a member of a peer group.
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp rpki server

To close the TCP connection to the specified Resource Public Key Infrastructure (RPKI) server, purge SOVC records downloaded from that server, renegotiate the TCP connection, and redownload SOVC records, use the clear ip bgp rpki server command in privileged EXEC mode.

clear ip bgp rpki server {ipv4-address | ipv6-address} port port-number [reset-only]

Syntax Description


`ipv4-address`	IPv4 address of the RPKI server.
`ipv6-address`	IPv6 address of the RPKI server.
port `port-number`	Specifies the port number of the RPKI server.
reset-only	(Optional) Purges all downloaded SOVC records from the specified server, sends a Reset Query PDU to the server, and redownloads all SOVC records, but does not close the TCP connection.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
XE 3.5S	This command was introduced.
15.2(1)S	This command was integrated into Cisco IOS Release 15.2(1)S.
15.2(4)S	This command was implemented on the Cisco 7200 series routers.

Usage Guidelines

Use this command without the reset-only keyword to close the TCP connection to the indicated cache server, purge all SOVC records downloaded from that server, and then renegotiate the TCP connection(s) and redownload all SOVC records. If there is no TCP connection, the router will ignore the 60-second reconnect timer and try to connect right away.

Use this command with the reset-only keyword to purge all downloaded SOVC records from that server, send a Reset Query PDU to the server, and redownload all SOVC records from the server.

If more than one server is at the same address, but at different ports, the router will clear only for the RPKI server at the specified address and port.

The command causes the immediate emptying of the RPKI table for SOVC records obtained from the indicated server. The command does not trigger an immediate update of the routing table. The routing table will instead be updated upon receipt of an EOD PDU from a server, or the expiration of the stale path timer for a server, or the removal of a server's configuration. Note that the server that sends the EOD, or whose stale path timer expires or is deconfigured, need not be the same server for which the clear command was issued.

Examples

The following example closes the TCP connection to the RPKI server at the specified address and port, purges all SOVC records downloaded from that server, renegotiates the TCP connection, and redownloads all SOVC records:

Router# clear ip bgp rpki server 192.168.14.2 port 1030

Related Commands


Command	Description
bgp rpki server	Connects to an RPKI server and enables the validation of BGP prefixes based on the AS from which the prefix originates.

clear ip bgp table-map

To reload information in the Border Gateway Protocol (BGP) routing table after a change in a table map or the route map referenced by a table map, use the clear ip bgp table-map command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] table-map

Syntax With Address Family Syntax

clear ip bgp [ipv4 | ipv6 | vpnv4 | vpnv6 {unicast | multicast} | vrf vrf-name] table-map

Syntax Description


vrf	(Optional) Specifies a virtual routing and forwarding instance.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
ipv4	(Optional) Reloads information for IPv4 address family sessions.
ipv6	(Optional) Reloads information for IPv6 address family sessions.
vpnv4	(Optional) Reloads information for IPv4 VPN address family sessions.
vpnv6	(Optional) Reloads information for IPv6 VPN address family sessions.
unicast	(Optional) Reloads information for unicast address family sessions.
multicast	(Optional) Reloads information for multicast address family sessions.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(14)S	This command was introduced.
12.0(21)S	This command was integrated into Cisco IOS Release 12.0(21)S.
12.0(22)S	The vpnv4 and ipv4 keywords were added.
12.1(13)E	This command was integrated into Cisco IOS Release 12.1(13)E.
12.2(13)T	This command was integrated into Cisco IOS Release 12.2(13)T.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp table-map command is used to clear or reload BGP routing tables. This command should be issued after a table map or the route map that it references is configured or changed, so that the change takes effect.

This command can be used to clear traffic-index information configured with the BGP Policy Accounting feature.

Examples

In the following example, a table map is configured and a traffic index is set. The new policy is applied after the clear ip bgp table-map command is entered.


Router(config)# route-map SET_BUCKET permit 10
 
Router(config-route-map)# match community 1 
Router(config-route-map)# set traffic-index 2
 
Router(config-route-map)# exit
Router(config)# router bgp 50000
 
Router(config-router)# address-family ipv4 
Router(config-router-af)# table-map SET_BUCKET
 
Router(config-router-af)# end
Router# clear ip bgp table-map

The following example reloads the BGP routing table for IPv4 unicast peering sessions:


Router# clear ip bgp ipv4 unicast table-map

Related Commands


Command	Description
bgp-policy	Enables BGP policy accounting or policy propagation on an interface.
table-map	Enables metrics and tag values to be modified or enables selective route download when the IP routing table is updated with BGP learned routes.

clear ip bgp update-group

To reset Border Gateway Protocol (BGP) connections for all the members of a BGP update group, use the clear ip bgp update-group command in privileged EXEC mode.

Syntax Without Address Family Syntax

clear ip bgp [vrf vrf-name] update-group [index-group | neighbor-address]

Syntax With Address Family Syntax

clear ip bgp [vrf vrf-name] [all | ipv4 {multicast | mdt | unicast} | ipv6 {multicast | unicast} | vpnv4 unicast | vpnv6 unicast] update-group [index-group | neighbor-address]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
vrf-name	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
`index-group`	(Optional) Specifies that the update group with the specified index number will be reset. The range of update group index numbers is from 1 to 4294967295.
`neighbor-address`	(Optional) Specifies the IP address of a single peer that will be reset. The value for this argument can be an IPv4 or IPv6 address.
all	(Optional) Specifies the reset of update group members in all address families.
ipv4	(Optional) Specifies the reset of update group members in IPv4 address family sessions.
multicast	(Optional) Specifies the reset of update group members in multicast address family sessions.
mdt	(Optional) Specifies the reset of update group members in multicast distribution tree (MDT) address family sessions.
unicast	(Optional) Specifies the reset of update group members in unicast address family sessions.
ipv6	(Optional) Specifies the reset of update group members in IPv6 address family sessions.
vpnv4	(Optional) Specifies the reset of update group members in Virtual Private Network Version 4 (VPNv4) address family sessions.
vpnv6	(Optional) Specifies the reset of update group members in Virtual Private Network Version 6 (VPNv6) address family sessions.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.0(24)S	This command was introduced.
12.2(18)S	This command was integrated into Cisco IOS Release 12.2(18)S.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T.
12.0(29)S	The mdt keyword was added.
12.2(27)SBC	This command was integrated into Cisco IOS Release 12.2(27)SBC.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp update-group command is used to clear BGP update group member sessions. If no keywords or arguments are specified, entering this command will recalculate all update groups. Specific index numbers for update groups and information about update-group membership is displayed in the output of the show ip bgp update-group and debug ip bgp groups commands.

When a change to outbound policy occurs, the BGP routing process will automatically recalculate update-group memberships and apply changes by triggering an outbound soft reset after a 1-minute timer expires. This behavior is designed to provide the network operator with time to change the configuration before the soft reset is initiated. You can immediately initiate the outbound soft reset before the timer expires by entering the clear ip bgp ip-address soft out command or immediately initiate a hard reset by entering the clear ip bgp ip-address command.

Note

In Cisco IOS Release 12.0(25)S, 12.3(2)T, and prior releases, the update group recalculation delay timer is set to 3 minutes.

Examples

In the following example, a hard reset is initiated for the peer 10.0.0.1:


Router# clear ip bgp 10.0.0.1

In the following example, all peers are cleared from the update group 10.0.0.1:

Router# clear ip bgp update-group 10.0.0.1

In the following example, update-group information for all peers in the index 1 update group is cleared:

Router# clear ip bgp update-group 1

In the following example, update-group information for all MDT address family session peers in the index 6 update group is cleared:

Router# clear ip bgp ipv4 mdt update-group 6

Related Commands


Command	Description
clear ip bgp	Resets a BGP connection or session.
debug ip bgp groups	Displays information related to the processing of BGP update groups.
show ip bgp replication	Displays BGP update-group replication statistics.
show ip bgp update-group	Displays information about BGP update groups.

clear ip bgp vpnv4

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv4 Virtual Private Network (VPNv4) address family sessions, use the clear ip bgp vpnv4 command in privileged EXEC mode.

clear ip bgp [vrf vrf-name] vpnv4 unicast autonomous-system-number [in [prefix-filter]] [out] [slow] [soft [in [prefix-filter] | out | slow]]

Syntax Description


vrf	(Optional) Specifies an instance of a routing table.
`vrf-name`	(Optional) Name of the Virtual Private Network (VPN) routing and forwarding (VRF) table to use for storing data.
unicast	Specifies the reset of unicast address family sessions.
`autonomous-system-number`	Specifies that sessions with BGP peers in the specified autonomous system will be reset. Number in the range from 1 to 65535. In Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, and later releases, 4-byte autonomous system numbers are supported in the range from 65536 to 4294967295 in asplain notation and in the range from 1.0 to 65535.65535 in asdot notation. In Cisco IOS Release 12.0(32)S12, 12.4(24)T, and Cisco IOS XE Release 2.3, 4-byte autonomous system numbers are supported in the range from 1.0 to 65535.65535 in asdot notation only. For more details about autonomous system number formats, see the router bgp command.
in	(Optional) Initiates inbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.0(22)S	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXH	This command was integrated into Cisco IOS Release 12.2(33)SXH.
12.0(32)S12	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.0(32)SY8	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.4(24)T	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
Cisco IOS XE Release 2.3	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.2(33)SXI1	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.0(33)S3	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
Cisco IOS XE Release 2.4	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
15.1(2)T	This command was modified. The vrf keyword and `vrf-name` argument were added.

Usage Guidelines

The clear ip bgp vpnv4 command can be used to initiate a hard reset or soft reconfiguration of VPNv4 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp vpnv4 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in VPNv4 unicast address family sessions, and the outbound session is unaffected:


Router#
 clear ip bgp vpnv4 unicast soft in

In the following example, the route refresh capability is enabled on theVPNv4 unicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the VPNv4 multicast address family neighbors, and the outbound session is unaffected:


Router#
 clear ip bgp vpnv4 unicast in

In the following example, a hard reset is initiated for neighbor sessions with all VPNv4 unicast address family routers in the autonomous system numbered 35700:


Router#
 clear ip bgp vpnv4 unicast 35700

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.


Router#
 clear ip bgp vpnv4 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in IPv4 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.


Router#
 clear ip bgp vpnv4 unicast 1.2

Related Commands


Command	Description
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp vpnv4 unicast dampening

To reset Border Gateway Protocol (BGP) route flap dampening for a particular IPv4 Virtual Private Network version 4 (VPNv4) address family prefix on a device that has no VRF concept, use the clear ip bgp vpnv4 unicast dampening command in privileged EXEC mode.

clear ip bgp vpnv4 unicast dampening rd route-distinguisher [network-address [network-mask] ]

Syntax Description


rd `route-distinguisher`	(Optional) VPN route distinquisher (RD) is either an autonomous system number (ASN)-relative RD, in which case it is composed of an autonomous system number and an arbitrary number, or it is an IP-address-relative RD, in which case it is composed of an IP address and an arbitrary number. You can enter a `route-distinguisher` in either of these formats: 16-bit autonomous system number: your 32-bit number. For example, 10:1. 32-bit IP address: your 16-bit number. For example, 192.168.122.15:1.
`network-address`	(Optional) IPv4 address for which the flap statistics are cleared.
`network-mask`	(Optional) IPv4 network mask.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
15.1(2)T	This command was introduced.

Usage Guidelines

Use this command on a device that has no VRF concept, such as an ASBR for Option B or a route reflector for Option C. Do not use this command on a Provider Edge (PE) router.

You can use the clear ip bgp vpnv4 unicast dampening command to clear stored route dampening information for the VPNv4 address family from the global VPN table. If you specify a route-distinguisher in the command, the command clears all the prefixes that contain the particular route-distinguisher. If you specify a VPNv4 address in the command, the command clears the route dampening information for that particular network address.

Note

On a PE router that has VRF concept, you can use the clear ip bgp vrf vrf name dampening command to clear the dampening information for all the routes in the same VRF. Use the clear ip bgp vrf vrf name dampening network-address command to clear the dampening information for a specific route belonging to a particular VRF.

Examples

The following example shows how to reset the flap dampening for a particular VPNv4 prefix:


Router# clear ip bgp vpnv4 unicast dampening rd 10:1 192.168.2.1 255.255.255.0

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or configures BGP route dampening parameters.
clear ip bgp flap-statistics	Resets BGP route dampening flap-statistics.
set dampening	Sets route dampening parameters in a route map.
show ip bgp dampened-paths	Displays BGP dampened routes.

clear ip bgp vpnv6

To reset Border Gateway Protocol (BGP) connections using hard or soft reconfiguration for IPv6 Virtual Private Network (VPNv6) address family sessions, use the clear ip bgp vpnv6 command in privileged EXEC mode.

clear ip bgp vpnv6 unicast autonomous-system-number [in [prefix-filter]] [out] [slow] [soft [in [prefix-filter] | out | slow]]

Syntax Description


unicast	Specifies the reset of unicast address family sessions.
`autonomous-system-number`	Specifies that sessions with BGP peers in the specified autonomous system will be reset. Number in the range from 1 to 65535. In Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, and later releases, 4-byte autonomous system numbers are supported in the range from 65536 to 4294967295 in asplain notation and in the range from 1.0 to 65535.65535 in asdot notation. In Cisco IOS Release 12.0(32)S12, 12.4(24)T, and Cisco IOS XE Release 2.3, 4-byte autonomous system numbers are supported in the range from 1.0 to 65535.65535 in asdot notation only. For more details about autonomous system number formats, see the router bgp command.
in	(Optional) Initiates inbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
prefix-filter	(Optional) Clears the existing outbound route filter (ORF) prefix list to trigger a new route refresh or soft reconfiguration, which updates the ORF prefix list.
out	(Optional) Initiates inbound or outbound reconfiguration. If neither the in nor out keywords are specified, both inbound and outbound sessions are reset.
slow	(Optional) Clears slow-peer status forcefully and moves it to original update group.
soft	(Optional) Initiates a soft reset. Does not tear down the session.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.2(2)T	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXH	This command was integrated into Cisco IOS Release 12.2(33)SXH.
12.0(32)S12	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.0(32)SY8	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.4(24)T	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
Cisco IOS XE Release 2.3	This command was modified. Support for 4-byte autonomous system numbers in asdot notation only was added.
12.2(33)SXI1	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.0(33)S3	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
Cisco IOS XE Release 2.4	This command was modified. Support for asplain notation was added and the default format for 4-byte autonomous system numbers is now asplain.
12.2(33)SRE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.
12.2(33)XNE	This command was modified. Support for 4-byte autonomous system numbers in asplain and asdot notation was added.

Usage Guidelines

The clear ip bgp vpnv6 command can be used to initiate a hard reset or soft reconfiguration of VPNv6 address family sessions. A hard reset tears down and rebuilds the specified peering sessions and rebuilds the BGP routing tables. A soft reconfiguration uses stored prefix information to reconfigure and activate BGP routing tables without tearing down existing peering sessions. Soft reconfiguration uses stored update information, at the cost of additional memory for storing the updates, to allow you to apply new BGP policy without disrupting the network. Soft reconfiguration can be configured for inbound or outbound sessions.

Generating Updates from Stored Information

To generate new inbound updates from stored update information (rather than dynamically) without resetting the BGP session, you must preconfigure the local BGP router using the neighbor soft-reconfiguration inbound command. This preconfiguration causes the software to store all received updates without modification regardless of whether an update is accepted by the inbound policy. Storing updates is memory intensive and should be avoided if possible.

Outbound BGP soft configuration has no memory overhead and does not require any preconfiguration. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Additions or changes to the BGP-related access lists
Changes to BGP-related weights
Changes to BGP-related distribution lists
Changes to BGP-related route maps

Dynamic Inbound Soft Reset

The route refresh capability, as defined in RFC 2918, allows the local router to reset inbound routing tables dynamically by exchanging route refresh requests to supporting peers. The route refresh capability does not store update information locally for non-disruptive policy changes. It instead relies on dynamic exchange with supporting peers. Route refresh is advertised through BGP capability negotiation. All BGP routers must support the route refresh capability.

To determine if a BGP router supports this capability, use the show ip bgp neighbors command. The following message is displayed in the output when the router supports the route refresh capability:


Received route refresh capability from peer.

If all BGP routers support the route refresh capability, use the clear ip bgp vpnv6 command with the in keyword. You need not use the soft keyword, because soft reset is automatically assumed when the route refresh capability is supported.

Note

After configuring a soft reset (inbound or outbound), it is normal for the BGP routing process to hold memory. The amount of memory that is held depends on the size of routing tables and the percentage of the memory chunks that are utilized. Partially used memory chunks will be used or released before more memory is allocated from the global router pool.

Examples

In the following example, a soft reconfiguration is initiated for the inbound sessions for BGP neighbors in VPNv6 unicast address family sessions, and the outbound session is unaffected:


Router#
 clear ip bgp vpnv6 unicast soft in

In the following example, the route refresh capability is enabled on the VPNv6 unicast address family BGP neighbors and a soft reconfiguration is initiated for all inbound session with the IPv6 multicast address family neighbors, and the outbound session is unaffected:


Router#
 clear ip bgp vpnv6 unicast in

In the following example, a hard reset is initiated for neighbor sessions with all VPNv6 unicast address family routers in the autonomous system numbered 35700:


Router#
 clear ip bgp vpnv6 unicast 35700

In the following example, a hard reset is initiated for BGP neighbors in VPNv6 unicast address family sessions in the 4-byte autonomous system numbered 65538 in asplain notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, Cisco IOS XE Release 2.4, or a later release.


Router#
 clear ip bgp vpnv6 unicast 65538

In the following example, a hard reset is initiated for BGP neighbors in VPNv6 unicast address family sessions in the 4-byte autonomous system numbered 1.2 in asdot notation. This example requires Cisco IOS Release 12.0(32)SY8, 12.0(32)S12, 12.2(33)SRE, 12.2(33)XNE, 12.2(33)SXI1, 12.4(24)T, and Cisco IOS XE Release 2.3, or a later release.


Router#
 clear ip bgp vpnv6 unicast 1.2

Related Commands


Command	Description
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.
show ip bgp neighbors	Displays information about BGP and TCP connections to neighbors.

clear ip bgp vpnv6 unicast dampening

To reset Border Gateway Protocol (BGP) route flap dampening for a particular IPv6 Virtual Private Network version 6 (VPNv6) address family prefix, use the clear ip bgp vpnv6 unicast dampening command in privileged EXEC mode.

clear ip bgp vpnv6 unicast dampening [rd route-distinguisher [network-address] ]

Syntax Description


rd `route-distinguisher`	(Optional) The VPN route distinquisher (RD) is either an autonomous system number (ASN)-relative RD, in which case it is composed of an autonomous system number and an arbitrary number, or it is an IP-address-relative RD, in which case it is composed of an IP address and an arbitrary number. You can enter a `route-distinguisher` in either of these formats: 16-bit autonomous system number: your 32-bit number. For example, 10:1. 32-bit IP address: your 16-bit number. For example, 192.168.122.15:1.
`network-address`	(Optional) VPNv6 address for which the flap statistics are cleared.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
15.1(2)T	This command was introduced.

Usage Guidelines

You can use the clear ip bgp vpnv6 unicast dampening command to clear stored route dampening information for the VPNv6 address family. If you specify a route-distinguisher in the command, the command clears all the prefixes that contain the particular route-distinguisher. If you specify a VPNv6 address in the command, the command clears the route dampening information for that particular network address.

Examples

The following example shows how to reset the flap dampening for a particular VPNv6 prefix:


Router# clear ip bgp vpnv6 unicast dampening rd 1:0 2001:1000::0/64

Related Commands


Command	Description
bgp dampening	Enables BGP route dampening or configures BGP route dampening parameters.
clear ip bgp flap-statistics	Resets BGP route dampening flap-statistics.
set dampening	Sets route dampening parameters in a route map.
show ip bgp dampened-paths	Displays BGP dampened routes.

clear ip prefix-list

To reset IP prefix-list counters, use the clear ip prefix-list command in privileged EXEC mode.

clear ip prefix-list [prefix-list-name] [network/length]

Syntax Description


`prefix-list-name`	(Optional) Name of the prefix list from which the hit count is to be cleared.
`network` / `length`	(Optional) Network number and length (in bits) of the network mask. The slash mark must precede the bit length value.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.0	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.

Usage Guidelines

The clear ip prefix-list command is used to clear prefix-list hit counters. The hit count is a value indicating the number of matches to a specific prefix list entry.

Examples

In the following example, the prefix-list counters are cleared for the prefix list named FIRST_LIST that matches the 10.0.0.0/8 prefix:


Router# clear ip prefix-list FIRST_LIST 10.0.0.0/8

Related Commands


Command	Description
distribute-list in (IP)	Filters networks received in updates.
distribute-list out (IP)	Suppresses networks from being advertised in updates.
ip prefix-list	Creates an entry in a prefix list.
ip prefix-list description	Adds a text description of a prefix list.
ip prefix-list sequence-number	Enables the generation of sequence numbers for entries in a prefix list.
redistribute (IP)	Redistributes routes from one routing domain into another routing domain.
show ip bgp regexp	Displays information about a prefix list or prefix list entries.

continue

To configure a route map to go to a route-map entry with a higher sequence number, use the continue command in route-map configuration mode. To remove a continue clause from a route map, use the no form of this command.

continue [sequence-number]

no continue

Syntax Description


`sequence-number`	(Optional) Route-map sequence number. If a route-map sequence number is not specified when configuring a continue clause, the continue clause will continue to the route-map entry with the next sequence number. This behavior is referred to as an “implied continue.”

Command Default

If the sequence number argument is not configured when this command is entered, the continue clause will go to the route-map entry with the next default sequence number.

If a route-map entry contains a continue clause and no match clause, the continue clause will be executed automatically.

Command Modes

Route-map configuration (config-route-map)

Command History


Release	Modification
12.0(22)S	This command was introduced.
12.3(2)T	This command was integrated into Cisco IOS Release 12.3(2)T.
12.2(18)S	This command was integrated into Cisco IOS Release 12.2(18)S.
12.0(31)S	Support for outbound route maps was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.

Usage Guidelines

The continue command supports inbound route maps only in Cisco IOS Release 12.2(18)S and prior releases. Support for both inbound and outbound route maps was introduced in Cisco IOS Release 12.0(31)S and later releases.

Route Map Operation Without Continue Clauses

A route map evaluates match clauses until a successful match occurs. After the match occurs, the route map stops evaluating match clauses and starts executing set clauses, in the order in which they were configured. If a successful match does not occur, the route map “falls through” and evaluates the next sequence number of the route map until all configured route-map entries have been evaluated or a successful match occurs. Each route-map sequence is tagged with a sequence number to identify the entry. Route-map entries are evaluated in order starting with the lowest sequence number and ending with the highest sequence number. If the route map contains only set clauses, the set clauses will be executed automatically, and the route map will not evaluate any other route-map entries.

Route Map Operation With Continue Clauses

When a continue clause is configured, the route map will continue to evaluate and execute match clauses in the specified route-map entry after a successful match occurs. The continue clause can be configured to go to (or jump to) a specific route-map entry by specifying the sequence number, or if a sequence number is not specified, the continue clause will go to the next sequence number. This behavior is called an “implied continue.” If a match clause exists, the continue clause is executed only if a match occurs. If no successful matches occur, the continue clause is ignored.

Match Operations With Continue Clauses

If a match clause does not exist in the route-map entry but a continue clause does, the continue clause will be automatically executed and go to the specified route-map entry. If a match clause exists in a route-map entry, the continue clause is executed only when a successful match occurs. When a successful match occurs and a continue clause exists, the route map executes the set clauses and then goes to the specified route-map entry. If the next route map contains a continue clause, the route map will execute the continue clause if a successful match occurs. If a continue clause does not exist in the next route map, the route map will be evaluated normally. If a continue clause exists in the next route map but a match does not occur, the route map will not continue and will “fall through” to the next sequence number if one exists.

Note

If the number of community lists in a match community clause within a route map exceed 256 characters in a line, you must nvgen multiple match community statements in a new line.

Set Operations With Continue Clauses

Set clauses are saved during the match clause evaluation process and executed after the route-map evaluation is completed. The set clauses are evaluated and executed in the order in which they were configured. Set clauses are only executed after a successful match occurs, unless the route map does not contain a match clause. The continue statement proceeds to the specified route-map entry only after configured set actions are performed. If a set action occurs in the first route map and then the same set action occurs again, with a different value, in a subsequent route-map entry, the last set action will override any previous set actions that were configured with the same set command.

Note

A continue clause can be executed, without a successful match, if a route-map entry does not contain a match clause.

Examples

In the following example, continue clause configuration is shown.

The first continue clause in route-map entry 10 indicates that the route map will go to route-map entry 30 if a successful matches occurs. If a match does not occur, the route map will “fall through” to route-map entry 20. If a successful match occurs in route-map entry 20, the set action will be executed and the route-map will not evaluate any additional route-map entries. Only the first successful match ip address clause is supported.

If a successful match does not occur in route-map entry 20, the route-map will “fall through” to route-map entry 30. This sequence does not contain a match clause, so the set clause will be automatically executed and the continue clause will go to the next route-map entry because a sequence number is not specified.

If there are no successful matches, the route-map will “fall through” to route-map entry 30 and execute the set clause. A sequence number is not specified for the continue clause so route-map entry 40 will be evaluated.


Router(config)# route-map ROUTE-MAP-NAME permit 10
 
Router(config-route-map)# match ip address 1
 
Router(config-route-map)# match metric 10
 
Router(config-route-map)# set as-path prepend 10
 
Router(config-route-map)# continue 30
 
Router(config-route-map)# exit 
Router(config)# route-map ROUTE-MAP-NAME permit 20
 
Router(config-route-map)# match ip address 2
 
Router(config-route-map)# match metric 20 
Router(config-route-map)# set as-path prepend 10 10 
Router(config-route-map)# exit 
Router(config)# route-map ROUTE-MAP-NAME permit 30 
Router(config-route-map)# set as-path prepend 10 10 10 
Router(config-route-map)# continue
 
Router(config-route-map)# exit
 
Router(config)# route-map ROUTE-MAP-NAME permit 40
Router(config-route-map)# match community 10:1
Router(config-route-map)# set local-preference 104
Router(config-route-map)# exit

Related Commands


Command	Description
aggregate-address	Creates an aggregate entry in a BGP or multicast BGP database.
match as-path	Match BGP autonomous system path access lists.
match community	Matches a BGP community.
match extcommunity	Matches a BGP extended community.
match interface (IP)	Distributes routes that have their next hop out one of the interfaces specified.
match ip address	Distributes any routes that have a destination network number address permitted by a standard or extended access list, or performs policy routing on packets.
match ip next-hop	Redistributes any routes that have a next-hop router address passed by one of the access lists specified.
match ip route-source	Redistributes routes that have been advertised by routers and access servers at the address specified by the access lists.
match length	Bases policy routing on the Level 3 length of a packet.
match metric (IP)	Redistributes routes with the metric specified.
match mpls-label	Redistributes routes that include MPLS labels if the routes meet the conditions specified in the route map.
match route-type (IP)	Redistributes routes of the specified type.
match tag	Redistributes routes in the routing table that match the specified tags.
neighbor default-originate	Allows a BGP speaker (the local router) to send the default route 0.0.0.0 to a neighbor for use as a default route.
neighbor route-map	Applies a route map to incoming or outgoing routes.
neighbor remote-as	Adds an entry to the BGP or multiprotocol BGP neighbor table.
redistribute (IP)	Redistributes routes from one routing domain into another routing domain.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol to another, or enables policy routing.
set as-path	Modifies an autonomous system path for BGP routes.
set automatic-tag	Automatically computes the tag value in a route-map configuration.
set comm-list delete	Removes communities from the community attribute of an inbound or outbound update.
set community	Sets the BGP communities attribute.
set dampening	Sets the BGP route dampening factors.
set default interface	Indicates where to output packets that pass a match clause of a route map for policy routing and have no explicit route to the destination.
set extcommunity	Sets the BGP extended communities attribute.
set interface	Indicates where to output packets that pass a match clause of route map for policy routing.
set ip default next-hop	Indicates where to output packets that pass a match clause of a route map for policy routing and for which the Cisco IOS software has no explicit route to a destination.
set ip default next-hop verify-availability	Configures a router to check the CDP database for the availability of an entry for the default next hop that is specified by the set ip default next-hop command.
set ip next-hop	Indicates where to output packets that pass a match clause of a route map for policy routing.
set ip next-hop verify-availability	Configures policy routing to verify if the next hops of a route map are CDP neighbors before policy routing to those next hops.
set ip precedence	Sets the precedence value in the IP header.
set level (IP)	Indicates where to import routes.
set local-preference	Specifies a preference value for the autonomous system path.
set mpls-label	Enables a route to be distributed with an MPLS label if the route matches the conditions specified in the route map.
set next-hop	Specifies the address of the next hop.
set nlri	This command was replaced by the address-family ipv4 and address-family vpnv4 commands.
set origin (BGP)	Sets the BGP origin code.
set qos-group	Sets a group ID that can be used later to classify packets.
set tag (IP)	Sets the value of the destination routing protocol.
set traffic-index	Defines where to output packets that pass a match clause of a route map for BGP policy accounting.
set weight	Specifies the BGP weight for the routing table.
show ip bgp	Displays entries in the BGP routing table.
show route-map	Displays all route maps configured or only the one specified.

debug ip bgp event rpki

To display information related to the BGP—Origin AS Validation feature and the process of connecting to a Resource Public Key Infrastructure (RPKI) server to download prefix information, use the debug ip bgp event rpki command in privileged EXEC mode. To disable debugging output, use the no form of this command.

debug ip bgp event rpki

no debug ip bgp event rpki

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Release 3.5S	This command was introduced.
15.2(1)S	This command was integrated into Cisco IOS Release 15.2(1)S.
15.2(4)S	This command was implemented on the Cisco 7200 series routers.

Usage Guidelines

This command provides details about the following events:

Gain/loss of connectivity to cache server
Receipt of serial notify
Sending of serial query
Sending of reset query
Receipt of End of Data
Receipt of cache reset
Error report sent or received
Expiration of stale path timer

Examples

The following example enables debugging of events related to the BGP—Origin AS Validation feature:


Router# debug ip bgp event rpki

Related Commands


Command	Description
bgp rpki server	Connects to an RPKI server and enables the validation of BGP prefixes based on the AS from which the prefix originates.

debug ip bgp igp-metric ignore

To display information related to the system ignoring the Interior Gateway Protocol (IGP) metric during best path selection, use the debug ip bgp igp-metric ignore command in privileged EXEC mode. To disable such debugging output, use the no form of this command.

debug ip bgp igp-metric ignore

no debug ip bgp igp-metric ignore

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE Release 3.4S	This command was introduced.
15.2(3)T	This command was integrated into Cisco IOS Release 15.2(3)T.
15.2(4)S	This command was integrated into Cisco IOS Release 15.2(4)S.

Usage Guidelines

You might use this command if the path you expected to be chosen as the best path at the shadow route reflector was not chosen as such. That could be because the bgp bestpath igp-metric ignore command makes the best path algorithm choose the same best path as the primary route reflector if they are not colocated.

Examples

The following example shows how to enable debugging of events related to the system ignoring the IGP metric during best path selection:


Router# debug ip bgp igp-metric ignore

Related Commands


Command	Description
bgp bestpath igp-metric ignore	Specifies that the system ignore the IGP metric during best path selection.

debug ip bgp import

To display debugging information related to importing IPv4 prefixes from the BGP global routing table into a VRF table or exporting from a VRF table into the BGP global table, use the debug ip bgp import command in privileged EXEC mode. To disable the display of such debugging information, use the no form of this command.

debug ip bgp import {events | updates [access-list | expanded-access-list]}

no debug ip bgp import {events | updates [access-list | expanded-access-list]}

Syntax Description


events	Displays messages related to IPv4 prefix import events.
updates	Displays messages related to IPv4 prefix import updates.
`access-list`	(Optional) Number of the access list used to filter debugging messages. The range is from 1 to 199.
`expanded-access-list`	(Optional) Number of the expanded access list used to filter debugging messages. The range is from 1300 to 2699.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
12.0(29)S	This command was introduced.
12.2(25)S	This command was integrated into Cisco IOS Release 12.2(25)S.
12.3(14)T	This command was integrated into Cisco IOS Release 12.3(14)T.
12.2(27)SBC	This command was integrated into Cisco IOS Release 12.2(27)SBC.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXH	This command was integrated into Cisco IOS Release 12.2(33)SXH.
15.2(4)S	This command was modified. The output now includes information for the BGP Support for IP Prefix Export from a VRF to the Global Table feature.
Cisco IOS XE Release 3.7S	This command was modified. The output now includes information for the BGP Support for IP Prefix Export from a VRF to the Global Table feature.

Usage Guidelines

Use this command to display debugging information related to the BGP Support for IP Prefix Import from Global Table into a VRF Table feature or the BGP Support for IP Prefix Export from a VRF Table into Global Table feature. The former feature provides the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map. The latter feature provides the capability to export IPv4 or IPv6 prefixes from a VRF table into the global table using an export route map.

Examples

The following example configures IPv4 prefix import debugging messages for both import events and import updates to be displayed on the console of the router:


Router# debug ip bgp import events
 
BGP import events debugging is on
Router# debug ip bgp import updates
BGP import updates debugging is on for access list 3
00:00:50: %BGP-5-ADJCHANGE: neighbor 10.2.2.2 Up 
00:01:06: BGP: reevaluate IPv4 Unicast routes in VRF academic
00:01:06: BGP: 0 routes available (limit: 1000)
00:01:06: BGP: import IPv4 Unicast routes to VRF academic
00:01:06: BGP(2)-VRF(academic): import pfx 100:1:10.30.1.0/24 via 10.2.2.2
00:01:06: BGP: accepted 8 routes (limit: 1000)
00:01:06: BGP: reevaluate IPv4 Multicast routes in VRF multicast
00:01:06: BGP: 0 routes available (limit: 2)
00:01:06: BGP: import IPv4 Multicast routes to VRF multicast
00:01:06: %BGP-4-AFIMPORT: IPv4 Multicast prefixes imported to multicast vrf reached the 
limit 2
00:01:06: BGP: accepted 2 routes (limit: 2)
00:01:06: BGP: reevaluate IPv4 Unicast routes in VRF BLUE 
00:01:06: BGP: 0 routes available (limit: 1000)
00:01:06: BGP: import IPv4 Unicast routes to VRF BLUE 
00:01:06: BGP: accepted 3 routes (limit: 1000)

The table below describes the significant fields shown in the display.

Table 1. debug ip bgp import Field Descriptions
Field	Description
BGP: accepted 2 routes (limit: 2)	Number of routes imported into the VRF, and the default or user-defined prefix import limit.
BGP: reevaluate IPv4 Unicast routes in VRF BLUE	Prefix was imported during BGP convergence and is being reevaluated for the next scan cycle.
BGP: 0 routes available (limit: 1000)	Number of routes available from the import source, and the default or user-defined prefix import limit.
BGP: import IPv4 Unicast routes to VRF BLUE	Import map and prefix type (unicast or multicast) that is being imported into the specified VRF.

The following is a sample debug message for the IP prefix export from a VRF table to global table:


Device# debug ip bgp import events
 
*Jul 12 10:06:48.357: BGP GBL-IMP: vpn1:VPNv4 Unicast:base 1:1:192.168.4.0/24
-> global:IPv4 Unicast:base Creating importing net.
  4.4.4.4 (metric 11) from 4.4.4.4 (4.4.4.4)
   Origin IGP, metric 0, localpref 100, valid, internal, best
   Extended Community: RT:1:1
   mpls labels in/out nolabel/16

Related Commands


Command	Description
clear ip bgp	Resets a BGP connection.
export map (VRF table to global table)	Exports IP prefixes from a VRF table to the global routing table based on a route map.
import map	Imports IP prefixes from the global routing table to a VRF table based on a route map.

debug ip bgp route-server

To turn on debugging for a BGP route server, use the debug ip bgp route-server command in privileged EXEC mode. To disable debugging output, use the no form of this command.

debug ip bgp route-server {client | context | event | import | policy} [detail]

no debug ip bgp route-server {client | context | event | import | policy} [detail]

Syntax Description


client	Displays information about BGP route server clients.
context	Displays information about BGP route server contexts.
event	Displays information about route server events, such as importing into the virtual RS table.
import	Displays information about BGP route server import maps.
policy	Displays information about the policy path process.
detail	(Optional) Displays detailed debugging information.

Command Modes

Privileged EXEC (#)

Command History


Release	Modification
Cisco IOS XE 3.3S	This command was introduced.
15.2(3)T	This command was integrated into Cisco IOS Release 15.2(3)T.

Usage Guidelines

Use this command to turn on debugging of a BGP router server.

Caution

The detail keyword is used for complex issues and should only be turned on when you are debugging with a Cisco representative.

Examples

In the following example, BGP route server client debugging is turned on:


Router# debug ip bgp route-server client

Related Commands


Command	Description
import-map	Configures flexible policy handling by a BGP route server.
neighbor route-server-client	Specifies on a BGP route server that a neighbor is a route server client.
route-server-context	Creates a route-server context in order to provide flexible policy handling for a BGP route server.

debug ip bgp sso

To display Border Gateway Protocol (BGP)-related stateful switchover (SSO) events or debugging information for BGP-related interactions between the active Route Processor (RP) and the standby RP, use the debug ip bgp sso command in privileged EXEC mode. To disable debugging output, use the no form of this command.

debug ip bgp sso {events | transactions} [detail]

no debug ip bgp sso {events | transactions} [detail]

Syntax Description


events	Displays BGP-related SSO failures.
transactions	Displays debugging information for failed BGP-related interactions between the active RP and the standby RP.
detail	(Optional) Displays detailed debugging information about successful BGP-related SSO operations and successful BGP-related interactions between the active and the standby RP.

Command Modes

Privileged EXEC

Command History


Release	Modification
12.2(28)SB	This command was introduced.
12.2(33)SRB1	This command was integrated into Cisco IOS Release 12.2(33)SRB1.
15.0(1)S	This command was integrated into Cisco IOS Release 15.0(1)S.
Cisco IOS XE 3.1S	This command was integrated into Cisco IOS XE Release 3.1S.

Usage Guidelines

The debug ip bgp sso command is used to display BGP-related SSO events or debugging information for BGP-related interactions between the active RP and the standby RP. This command is useful for monitoring or troubleshooting BGP sessions on a provider edge (PE) router during an RP switchover or during a planned In-Service Software Upgrade (ISSU).

Examples

The following is sample output from the debug ip bgp sso command with the events keyword. The following output indicates that the 10.34.32.154 BGP session is no longer SSO capable.


*Mar 28 02:29:43.526: BGPSSO: 10.34.32.154 reset SSO and decrement count

Tip

Use the show ip bgp vpnv4 all neighbors command to display the reason that the SSO-capable BGP session has been disabled.

The following is sample output from the debug ip bgp sso command with the transactions keyword. The following output shows an SSO notification indicating that the SSO capability is pending for 602 BGP neighbors. This notification is generated as the state between the active and standby RP is being synchronized during the bulk synchonization phase of SSO initialization. During this phase, the Transmission Control Blocks (TCBs) must be synchronized with the TCBs on the standby RP before SSO initialization is complete.


*Mar 28 02:32:12.102: BGPSSO: tcp sso notify pending for 602 nbrs

default (bmp)

To enable the default form of a command used to configure BGP Monitoring Protocol (BMP) servers, use the default command in BMP server configuration mode.

default {activate | address {ipv4-addr | ipv6-addr} port-number port-number | description LINE server-description | exit-bmp-server-mode | failure-retry-delay | flapping-delay | initial-delay | set ip dscp dscp-value | stats-reporting-period | update-source interface-type interface-number}

Syntax Description


activate	Sets the default connection between the BMP servers and BGP BMP neighbors.
address	Sets the default IP address on the BMP servers.
`ipv4-addr`	Specifies the default IPv4 address for the BMP servers.
`ipv4-addr`	Specifies the default IPv6 address for the BMP servers.
port-number `port-number`	Sets the default port number for the listening BMP servers. The port number of the listening BMP servers range from 1 to 65535. The value specified for the BMP server in this range becomes the default port number.
description LINE `server-description`	Sets the default description of the BMP servers. The text defined for the `server-description` argument becomes the default line description for specific BMP servers.
exit-bmp-server-mode	Sets the default exit flag from BMP server configuration mode.
failure-retry-delay	Sets the default delay for retries upon failures when sending BMP server updates.
flapping-delay	Sets the default delay for flapping when sending BMP server updates.
initial-delay	Sets the default delay when sending the initial BMP server updates.
set ip dscp `dscp-value`	Sets the default IP Differentiated Services Code Point (DSCP) values for BMP servers. The value specified for the `dscp-value` argument, which ranges from 0 to 7, becomes the default value.
stats-reporting-period	Sets the default reporting period for the statistics of BMP servers.
update-source `interface-type` `interface-number`	Sets the default interface source of routing updates on a BMP server. The interface specified for the `interface-type` `interface-number` argument becomes the default value.

Command Default

The default form of the commands used to configure BMP servers is not set.

Command Modes

BMP server configuration

Command History


Release	Modification
15.4(1)S	This command was introduced.
Cisco IOS XE Release 3.11S	This command was integrated into Cisco IOS XE Release 3.11S.

Usage Guidelines

Use the bmp server command to enter BMP server configuration mode and configure a specific BMP server. To configure BGP BMP neighbors to which the BMP servers establish a connection, use the neighbor bmp-activate command in router configuration mode. Use the show ip bgp bmp command to verify default forms and values of the commands and parameters, respectively, that have been configured.

Examples

The following example show how to enter BMP server configuration mode and assign default value to the set ip dscp command:


Device> enable
Device# configure terminal
Device(config)# router bgp 65000
Device(config-router)# bmp server 1
Device(config-router-bmpsrvr)# activate
Device(config-router-bmpsrvr)# address 10.1.1.1 port-number 8000
Device(config-router-bmpsrvr)# default set ip dscp 6
Device(config-router-bmpsrvr)# exit-bmp-server-mode
Device(config-router)# bmp server 2
Device(config-router-bmpsrvr)# activate
Device(config-router-bmpsrvr)# address 20.1.1.1 port-number 9000
Device(config-router-bmpsrvr)# default set ip dscp 6
Device(config-router-bmpsrvr)# end

The following is sample output from the show ip bgp bmp server detail command for BMP server number 1 and 2. The “IP Precedence value” field in the output displays the default IP DSCP value (indicating Internetwork control) set for BMP servers 1 and 2:


Device# show ip bgp bmp server detail | include IP Precedence

IP Precedence value : 6
IP Precedence value : 6

Related Commands


Command	Description
bmp server	Enters BMP server configuration mode to configure specific BMP servers.
neighbor bmp-activate	Activates BMP monitoring for BGP neighbors.
show ip bgp bmp	Displays information about BMP servers and neighbors.

default-information originate (BGP)

To configure a Border Gateway Protocol (BGP) routing process to distribute a default route (network 0.0.0.0), use the default-information originate command in address family or router configuration mode. To disable the advertisement of a default route, 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

No default behavior or values

Command Modes

Address family configuration (config-router-af)

Router configuration (config-router)

Command History


Release	Modification
10.0	This command was introduced.
12.0(7)T	Address family configuration mode support was added.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX	This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.

Usage Guidelines

The default-information originate command is used to configure a BGP routing process to advertise a default route (network 0.0.0.0). A redistribution statement must also be configured to complete this configuration or the default route will not be advertised.

The configuration of the default-information originate command in BGP is similar to the configuration of the network (BGP) command. The default-information originate command, however, requires explicit redistribution of the route 0.0.0.0. The network command requires only that the route 0.0.0.0 is present in the Interior Gateway Protocol (IGP) routing table. For this reason, the network command is preferred.

Note

The default-information originate command should not be configured with the neighbor default-originate command on the same router. You should configure one or the other.

Examples

In the following example, the router is configured to redistribute a default route from OSPF into the BGP routing process:


Router(config)# router bgp 50000
Router(config-router)# address-family ipv4 unicast
 
Router(config-router-af)# default-information originate
 
Router(config-router-af)# redistribute ospf 100
 
Router(config-router-af)# end

Related Commands


Command	Description
neighbor default-originate	Configures a BGP routing process to send a default route (network 0.0.0.0) to a neighbor.
network (BGP)net	Specifies the list of networks for the BGP routing process.
redistribute (IP)	Redistributes routes from one routing domain into another routing domain.

default-metric (BGP)

To set a default metric for routes redistributed into Border Gateway Protocol (BGP), use the default-metric command in address family or router configuration mode. To remove the configured value and return BGP to default operation, use the no form of this command.

default-metric number

no default-metric number

Syntax Description


`number`	Default metric value applied to the redistributed route. The range of values for this argument is from 1 to 4294967295.

Command Default

The following is default behavior if this command is not configured or if the no form of this command is entered:

The metric of redistributed interior gateway protocol (IGP) routes is set to a value that is equal to the interior BGP (iBGP) metric.
The metric of redistributed connected and static routes is set to 0.

When this command is enabled, the metric for redistributed connected routes is set to 0.

Command Modes

Address family configuration (config-router-af)

Router configuration (config-router)

Command History


Release

Bias-Free Language

Results

Chapter: BGP Commands: C through I

BGP Commands: C through I

clear bgp l2vpn evpn

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear bgp nsap

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear bgp nsap dampening

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear bgp nsap external

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear bgp nsap flap-statistics

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear bgp nsap peer-group

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear proximity ip bgp

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear ip bgp dampening

Syntax Without Address Family Syntax

Syntax With Address Family Syntax

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear ip bgp external

Syntax Without Address Family Syntax

Syntax With Address Family Syntax

Syntax Description

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

clear ip bgp flap-statistics

Syntax Without Address Family Syntax

Syntax With Address Family Syntax

Syntax Description

Command Modes