Table Of Contents

match as-path

match community

match extcommunity

match local-preference

match policy-list

match source-protocol

maximum-paths eibgp

maximum-paths ibgp

neighbor activate

neighbor advertise-map

neighbor advertisement-interval

neighbor capability orf prefix-list

neighbor default-originate

neighbor description

neighbor disable-connected-check

neighbor distribute-list

neighbor dmzlink-bw

neighbor ebgp-multihop

neighbor fall-over

neighbor filter-list

neighbor ha-mode graceful-restart

neighbor inherit peer-policy

neighbor inherit peer-session

neighbor local-as

neighbor maximum-prefix

neighbor maximum-prefix (BGP)

neighbor next-hop-self

neighbor next-hop-unchanged

neighbor password

neighbor peer-group (assigning members)

neighbor peer-group (creating)

neighbor prefix-list

neighbor remote-as

neighbor remove-private-as

neighbor route-map

neighbor route-reflector-client

neighbor send-community

neighbor shutdown

neighbor soft-reconfiguration

neighbor soo

match as-path

To match a BGP autonomous system path access list, use the match as-path command in route-map configuration mode. To remove a path list entry, use the no form of this command.

match as-path path-list-number

no match as-path path-list-number

Syntax Description

path-list-number

Autonomous system path access list. An integer from 1 to 199.

Defaults

No path lists are defined.

Command Modes

Route-map configuration

Command History

Release	Modification
10.0	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 values set by the match as-path and set weight commands override global values. For example, the weights assigned with the match as-path and set weight route-map configuration commands override the weight assigned using the neighbor weight command.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

Examples

The following example sets the autonomous system path to match BGP autonomous system path access list 20:

route-map IGP2BGP

 match as-path 20

Related Commands

Command	Description
match community	Matches a BGP 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 that is permitted by a standard or extended access list, and 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 metric (IP)	Redistributes routes with the metric specified.
match route-type (IP)	Redistributes routes of the specified type.
match tag	Redistributes routes in the routing table that match the specified tags.
neighbor weight	Assigns weight to a neighbor connection.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into 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 community	Sets the BGP communities attribute.
set level (IP)	Indicates where to import routes.
set local-preference	Specifies a preference value for the autonomous system path.
set metric (BGP, OSPF, RIP)	Sets the metric value for a routing protocol.
set metric-type	Sets the metric type for the destination routing protocol.
set next-hop	Specifies the address of the next hop.
set origin (BGP)	Sets the BGP origin code.
set tag (IP)	Sets the value of the destination routing protocol.
set weight	Specifies the BGP weight for the routing table.

match community

To match a Border Gateway Protocol (BGP) community, use the match community command in route-map configuration mode. To remove the match community command from the configuration file and restore the system to its default condition where the software removes the BGP community list entry, use the no form of this command.

match community {standard-list-number | expanded-list-number | community-list-name [exact]}

no match community {standard-list-number | expanded-list-number | community-list-name [exact]}

Syntax Description

standard-list-number	Specifies a standard community list number from 1 to 99 that identifies one or more permit or deny groups of communities.
expanded-list-number	Specifies an expanded community list number from 100 to 500 that identifies one or more permit or deny groups of communities.
community-list-name	The community list name.
exact	(Optional) Indicates that an exact match is required. All of the communities and only those communities specified must be present.

Command Default

No community list is matched by the route map.

Command Modes

Route-map configuration

Command History

Release	Modification
12.1	This command was introduced.
12.1(9)E	Named community list support was integrated into Cisco IOS Release 12.1(9)E.
12.2(8)T	Named community list support was integrated into Cisco IOS Release 12.2(8)T.
12.0(22)S	The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.0(22)S.
12.2(14)S	The maximum number of expanded community lists was changed from 199 to 500 and named community list support were integrated into Cisco IOS Release 12.2(14)S.
12.2(15)T	The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.2(15)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.

Usage Guidelines

A route map can have several parts. Any route that does not match at least one match command relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

Matching based on community list number is one of the types of match commands applicable to BGP.

Examples

The following example shows that the routes matching community list 1 will have the weight set to 100. Any route that has community 109 will have the weight set to 100.

Router(config)# ip community-list 1 permit 109

Router(config)# route-map set_weight

Router(config-route-map)#  match community 1

Router(config-route-map)# set weight 100

The following example shows that the routes matching community list 1 will have the weight set to 200. Any route that has community 109 alone will have the weight set to 200.

Router(config)# ip community-list 1 permit 109

Router(config)# route-map set_weight

Router(config-route-map)# match community 1 exact

Router(config-route-map)# set weight 200

In the following example, the routes that match community list LIST_NAME will have the weight set to 100. Any route that has community 101 alone will have the weight set to 100.

Router(config)# ip community-list LIST_NAME permit 101

Router(config)# route-map set_weight

Router(config-route-map)# match community LIST_NAME 

Router(config-route-map)# set weight 100

The following example shows that the routes that match expanded community list 500. Any route that has extended community 1 will have the weight set to 150.

Router(config)# ip community-list 500 permit [0-9]*

Router(config)# route-map MAP_NAME permit 10

Router(config-route-map)# match extcommunity 500

Router(config-route-map)# set weight 150

Related Commands

Command	Description
ip community-list	Creates a community list for BGP and controls access to it.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another.
set weight	Specifies the BGP weight for the routing table.

match extcommunity

To match Border Gateway Protocol (BGP) extended community list attributes, use the match extcommunity command in route-map configuration mode. To remove the match extcommunity command from the configuration file and remove the BGP extended community list attribute entry, use the no form of this command.

match extcommunity standard-list-number expanded-list-number

no match extcommunity standard-list-number expanded-list-number

Syntax Description

standard-list-number	A standard extended community list number from 1 to 99 that identifies one or more permit or deny groups of extended community attributes.
expanded-list-number	An expanded extended community list number from 100 to 500 that identifies one or more permit or deny groups of extended community attributes.

Defaults

This command is disabled by default.

Command Modes

Route-map configuration

Command History

Release	Modification
12.1	This command was introduced.
12.0(22)S	The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.0(22)S.
12.2(15)T	The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.2(15)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.

Usage Guidelines

Extended community attributes are used to configure, filter, and identify routes for virtual routing and forwarding instances (VRFs) and Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs).

The match extcommunity command is used to configure match clauses that use extended community attributes in route maps. The range of numbers that can be configured with the match extcommunity command is from 1 to 500. All of the standard rules of match and set clauses apply to the configuration of extended community attributes.

Examples

The following example shows that the routes that match extended community list 500 will have the weight set to 100. Any route that has extended community 1 will have the weight set to 100.

Router(config)# ip extcommunity-list 500 rt 100:2

Router(config)# route-map MAP_NAME permit 10

Router(config-route-map)# match extcommunity 1

Router(config-route-map)# set weight 100

Related Commands

Command	Description
ip extcommunity-list	Creates an extended community list for BGP and controls access to it.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another.
set extcommunity	Sets BGP extended community attributes.
set weight	Specifies the BGP weight for the routing table.
show ip extcommunity-list	Displays routes that are permitted by the extended community list.
show route-map	Displays configured route maps.

match local-preference

To configure a route map to match routes based on the Border Gateway Protocol (BGP) local-preference attribute, use the match local-preference command in route-map configuration mode. To remove the match clause entry from the route map, use the no form of this command.

match local-preference value

no match local-preference value

Syntax Description

value

The local preference value. This argument can be entered as a number from 0 to 4294967295.

Command Default

Cisco IOS software uses a default value of 100 for the local-preference attribute. However, a local-preference value must be entered when configuring a match clause with this command.

Command Modes

Route-map configuration

Command History

Release	Modification
12.3(14)T	This command was introduced.
12.2(30)S	This command was integrated into Cisco IOS Release 12.2(30)S.

Usage Guidelines

The match local-preference command is used to filter routes based on the value of the local preference attribute. The local-preference attribute is a well-known discretionary attribute that is used to set the preference for an exit point within an autonomous system. The route with the highest local-preference value is preferred by the BGP best path selection process.

Redistributing OER Injected Routes

Optimized Edge Routing (OER) uses a local-preference value of 5000 (default) to move traffic to the preferred exit point in a BGP network (This value can be configured on the OER master controller). The match local-preference command can be used to redistribute OER injected routes within an autonomous system that is monitored and controlled by OER.

Examples

The following example configures the route-map name RED to match OER injected routes:

Router(config)# route-map RED permit 10 

Router(config-route-map)# match local-preference 5000 

Related Commands

Command	Description
bgp default local-preference	Changes the default local-preference value.
route-map (IP)	Defines conditions for redistributing routes.
set local-preference	Applies a local-preference value to routes that pass the match clause.

match policy-list

To configure a route map to evaluate and process a Border Gateway Protocol (BGP) policy list in a route map, use the match policy-list command in route-map configuration mode. To remove a path list entry, use the no form of this command.

match policy-list policy-list-name

no match policy-list policy-list-name

Syntax Description

policy-list-name

Name of the policy list to evaluate and process within the route map.

Defaults

This command is not enabled by default.

Command Modes

Route-map configuration

Command History

Release	Modification
12.0(22)S	This command was introduced.
12.2(15)T	This command was integrated into 12.2(15)T.
12.2(27)SBC	This command was integrated into Cisco IOS Release 12.2(27)SBC.

Usage Guidelines

When a policy list is referenced within a route map, all the match statements within the policy list are evaluated and processed.

Two or more policy lists can be configured with a route map. Policy lists can be configured within a route map to be evaluated with AND semantics or OR semantics.

Policy lists can also coexist with any other preexisting match and set statements that are configured within the same route map but outside of the policy lists.

When multiple policy lists perform matching within a route map entry, all policy lists match on the incoming attribute only.

Examples

The following configuration example creates a route map that references policy lists and separate match and set clauses in the same configuration:

Router(config)# route-map MAP-NAME-1 10

Router(config-route-map)# match ip-address 1

Router(config-route-map)# match policy-list POLICY-LIST-NAME-1 

Router(config-route-map)# set community 10:1

Router(config-route-map)# set local-preference 140

Router(config-route-map)# end

The following configuration example creates a route map that references policy lists and separate match and set clauses in the same configuration. This example processes the policy lists named POLICY-LIST-NAME-2 and POLICY-LIST-NAME-3 with OR semantics. A match is required from only one of the policy lists.

Router(config)# route-map MAP-NAME-2 10

Router(config-route-map)# match policy-list POLICY-LIST-NAME-2 POLICY-LIST-NAME-3

Router(config-route-map)# set community 10:1

Router(config-route-map)# set local-preference 140

Router(config-route-map)# end

Related Commands

Command	Description
ip policy-list	Creates a BGP policy list.
match as-path	References a policy list within a route map for evaluation and processing.
match community	Matches a BGP 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 that is permitted by a standard or extended access list, and 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 metric (IP)	Redistributes routes with the metric specified.
match route-type (IP)	Redistributes routes of the specified type.
match tag	Redistributes routes in the routing table that match the specified tags.
neighbor weight	Assigns weight to a neighbor connection.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.

match source-protocol

To match Enhanced Interior Gateway Routing Protocol (EIGRP) external routes based on a source protocol and autonomous system number, use the match source-protocol command in route-map configuration mode. To remove the protocol to be matched, use the no form of this command.

match source-protocol source-protocol [autonomous-system-number]

no match source-protocol source-protocol [autonomous-system-number]

Syntax Description

source-protocol	Protocol to match. The valid keywords are bgp, connected, eigrp, isis, ospf, rip, and static. There is no default.
autonomous-system-number	(Optional) Autonomous system number. This argument is not applicable to the connected, static, and rip keywords. The range is from 1 to 65535. There is no default.

Command Default

EIGRP external routes are not matched on a source protocol and autonomous system number.

Command Modes

Route-map configuration

Command History

Release	Modification
12.3(8)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.

Usage Guidelines

This command may not be useful with a redistribution operation that employs route maps because redistribution usually requires the configuration of a source protocol and an autonomous system value in order to redistribute. In many cases, it is more useful to configure a route map that includes matching the route type based on the source protocol and autonomous system using the distribute-list command for EIGRP.

Examples

The following example shows how to configure a route map to match a source protocol of BGP and an autonomous system 45000. When the match clause is true, the tag value of the destination routing protocol is set to 5. The route map is used to distribute incoming packets for an EIGRP process.

route-map metric_source

 match source-protocol bgp 45000

 set tag 5

!

router eigrp 45000 

 network 172.16.0.0

 distribute-list route-map metric_source in

Related Commands

Command	Description
distribute-list	Filters networks received in updates.
match as-path	Matches a BGP autonomous system path access list.
match community	Matches a BGP community.
match interface (IP)	Distributes any 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 that is permitted by a standard or extended access list, and 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 route-type (IP)	Redistributes routes of the specified type.
match tag	Redistributes routes in the routing table that match the specified tags.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.
set as-path	Modifies an autonomous system path for BGP routes.
set automatic-tag	Automatically computes the tag value.
set community	Sets the BGP communities attribute.
set level (IP)	Indicates where to import routes.
set local-preference	Specifies a preference value for the autonomous system path.
set metric (BGP, OSPF, RIP)	Sets the metric value for a routing protocol.
set metric-type	Sets the metric type for the destination routing protocol.
set next-hop	Specifies the address of the next hop.
set tag (IP)	Sets a tag value of the destination routing protocol.
set weight	Specifies the BGP weight for the routing table.

maximum-paths eibgp

To configure multipath load sharing for external BGP (eBGP) and internal (iBGP) routes, use the maximum-paths eibgp command in address family configuration mode. To disable multipath load sharing for eBGP and iBGP routes, use the no form of this command.

maximum-paths eibgp number-of-paths [import number-of-import-paths]

no maximum-paths eibgp number-of-paths [import number-of-import-paths]

Syntax Description

number-of-paths

Specifies the number of routes to install to the routing table. See the usage guidelines for the number of paths that can be configured with this argument.

import number-of-import-paths

(Optional) Specifies the number of redundant paths that can be configured as back up multipaths for a VRF. This keyword can only be configured under a VRF in address family configuration mode. Note We recommend that this feature is enabled only where needed and that the number of import paths be kept to the minimum (Typically, not more than two paths). For more information, see the related note in the usage guidelines of this command reference page.

Command Default

Border Gateway Protocol (BGP) by default will install only one best path in the routing table.

Command Modes

IPv4 VRF Address family configuration

Command History

Release	Modification
12.2(4)T	This command was introduced.
12.0(24)S	This command was integrated into Cisco IOS Release 12.0(24)S.
12.2(14)S	This command was integrated into Cisco IOS Release 12.2(14)S.
12.0(25)S	The import keyword was introduced.
12.3	The import keyword was integrated into Cisco IOS Release 12.3.
12.3(2)T	The maximum number of parallel routes was increased from 6 to 16.
12.2(25)S	The maximum number of parallel routes was increased from 6 to 16.
12.2(18)SXE	This command was integrated into Cisco IOS Release 12.2(18)SXE.
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.

Usage Guidelines

The maximum-paths eibgp command used to configure Border Gateway Protocol (BGP) multipath load sharing in an Multiprotocol Label Switching (MPLS) virtual private network (VPN) using eBGP and iBGP routes. This feature is configured under a VPN routing and forwarding instance (VRF) in address family configuration mode. The number of multipaths is configured separately for each VRF.

The number of paths that can be configured is determined by the version of Cisco IOS software. The following list shows current limits:

•Cisco IOS Release 12.0S based software: 8 paths

•Cisco IOS Release 12.3T based software: 16 paths

•Cisco IOS Release 12.2S based software: 32 paths

The maximum-paths eibgp command cannot be configured with the maximum-paths or maximum-paths ibgp command because the maximum-paths eibgp command is a superset of these commands.

---

Note The configuration of this command does not override the existing outbound routing policy.

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Configuring VRF Import Paths

A VRF will import only one path (best path) per prefix from the source VRF table, unless the prefix is exported with a different route-target. If the best path goes down, the destination will not be reachable until the next import event occurs, and then a new best path will be imported into the VRF table. The import event runs every 15 seconds by default.

The import keyword allows you to configure the VRF table to accept multiple redundant paths in addition to the best path. An import path is a redundant path, and it can have a next hop that matches an installed multipath.This feature should be used when there are multiple paths with identical next hops available to ensure optimal convergence times. A typical application of this feature is to configure redundant paths in a network that has multiple route reflectors for redundancy.

---

Note Configuring redundant paths with the import keyword can increase CPU and memory utilization significantly, especially in a network where there are many prefixes to learn and a large number of configured VRFs. It is recommended that this feature is only configured as necessary and that the minimum number of redundant paths are configured (Typically, not more than two).

---

Examples

In the following example, the router is configured to install six eBGP or iBGP routes into the VRF routing table:

Router(config)# router bgp 40000 

Router(config-router)# address-family ipv4 vrf YELLOW 

Router(config-router-af)# maximum-paths eibgp 6 

In the following example, the router is configured to install 4 equal-cost routes and 2 import routes (backup) in the VRF routing table:

Router(config)# router bgp 45000 

Router(config-router)# address-family ipv4 vrf GREEN 

Router(config-router-af)# maximum-paths eibgp 4 import 2 

In the following example, the router is configured to install 2 import routes in the VRF routing table:

Router(config)# router bgp 50000

Router(config-router)# address-family ipv4 vrf ORANGE 

Router(config-router-af)# maximum-paths eibgp import 2 

---

Note Separate VRFs must be configured with different route distinguisher to support separate multipath configurations.

---

Related Commands

Command	Description
maximum-paths	Configures the number of equal-cost routes that BGP will install in the routing table.
maximum-paths ibgp	Configures the number of equal-cost or unequal-cost routes that BGP will install in the routing table.
show ip bgp	Displays entries in the BGP routing table.

maximum-paths ibgp

To control the maximum number of parallel internal Border Gateway Protocol (iBGP) routes that can be installed in a routing table, use the maximum-paths ibgp command in router configuration mode. To restore the default value, use the no form of this command.

Router Configuration Mode

maximum-paths ibgp number-of-paths

no maximum-paths ibgp number-of-paths

Under VRF in Address Family Configuration Mode

maximum-paths ibgp {number-of-paths [import number-of-import-paths] | unequal-cost number-of-import-paths}

no maximum-paths ibgp {number-of-paths [import number-of-import-paths] | unequal-cost number-of-import-paths}

Syntax Description

number-of-paths	Specifies the number of routes to install to the routing table. See the usage guidelines section for the number of paths that can be configured with this argument.
unequal-cost	Specifies the number of unequal-cost routes to install in the routing table. See the usage guidelines section for the number of paths that can be configured with this argument. This keyword can only be configured under a VRF in address family configuration mode.
import number-of-import-paths	(Optional) Specifies the number of redundant paths that can be configured as back up multipaths for a VRF. This keyword can only be configured under a VRF in address family configuration mode. Note We recommend that this feature is enabled only where needed and that the number of import paths be kept to the minimum (Typically, not more than two paths). For more information, see the related note in the usage guidelines of this command reference page.

Command Default

BGP, by default, will install only one best path in the routing table.

Command Modes

Address-family configuration
Router configuration

Command History

Release	Modification
12.2(2)T	This command was introduced.
12.0(25)S	The import keyword was introduced in Cisco IOS Release 12.0(25)S.
12.2(14)S	This command was integrated into Cisco IOS Release 12.2(14)S.
12.2(14)SX	This command was integrated into Cisco IOS Release 12.2(14)SX.
12.3	The import keyword was integrated into Cisco IOS Release 12.3.
12.3(2)T	The maximum number of parallel routes was increased from 6 to 16.
12.2(25)S	This command was integrated into Cisco IOS Release 12.2(25)S for use in IPv6.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(25)SG	This command was integrated into Cisco IOS Release 12.2(25)SG.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

The maximum-paths ibgp command is used to configure equal-cost or unequal-cost multipath load sharing for iBGP peering sessions. In order for a route to be installed as a multipath in the BGP routing table, the route cannot have a next hop that is the same as another route that is already installed. The BGP routing process will still advertise a best path to iBGP peers when iBGP multipath load sharing is configured. For equal-cost routes, the path from the neighbor with the lowest router ID is advertised as the best path.

To configure equal-cost multipath load sharing, all path attributes must be the same. The path attributes include weight, local preference, autonomous system path (entire attribute and not just the length), origin code, Multi Exit Discriminator (MED), and Interior Gateway Protocol (IGP) distance.

The number of paths that can be configured is determined by the version of Cisco IOS software. The following list shows current limits:

•Cisco IOS Release 12.0S-based software: 8 paths

•Cisco IOS Release 12.3T-based software: 16 paths

•Cisco IOS Release 12.2S-based software: 32 paths

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Note In IPv6, the maximum-paths ibgp command does not work for prefixes learned from iBGP neighbors that have been configured with the send-label keyword. If multiple routes exist for such prefixes, all of them are inserted into the RIB when the maximum-paths ibgp command is configured, but only one is used and no load balancing occurs between equal-cost paths. The maximum-paths ibgp command works with 6PE only in Cisco IOS Release 12.2(25)S and subsequent 12.2S releases.

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Configuring VRF Import Paths

A VRF will import only one path (the best path) per prefix from the source VRF table, unless the prefix is exported with a different route-target. If the best path goes down, the destination will not be reachable until the next import event occurs, and then a new best path will be imported into the VRF table. The import event runs every 15 seconds by default.

The import keyword allows the network operator to configure the VRF table to accept multiple redundant paths in addition to the best path. This feature should be used when there are multiple paths with identical next hops available to ensure optimal convergence times. A typical application of this configuration option is to configure redundant paths in a network that has multiple route reflectors for redundancy.

---

Note Configuring redundant paths with the import keyword can increase CPU and memory utilization significantly, especially in a network where there are many prefixes to learn and a large number of configured VRFs. It is recommended that this feature is only configured as necessary and that the minimum number of redundant paths are configured (Typically, not more than two).

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Examples

The following example configuration installs 3 parallel iBGP paths in a non-Multiprotocol Label Switching (MPLS) topology:

Router(config)# router bgp 100 

Router(config-router)# maximum-paths ibgp 3 

The following example configuration installs 3 parallel iBGP paths in an MPLS Virtual Private Network (VPN) topology:

Router(config)# router bgp 100 

Router(config-router)# address-family ipv4 unicast vrf RED 

Router(config-route-af)# maximum-paths ibgp 3 

The following example configuration installs 2 parallel routes in the VRF table:

Router(config)# router bgp 100 

Router(config-router)# address-family ipv4 vrf BLUE 

Router(config-router-af)# maximum-paths ibgp 2 import 2 

Router(config-router-af)# end 

The following example configuration installs 2 parallel routes in the VRF table:

Router(config)# router bgp 100 

Router(config-router)# address-family ipv4 vrf GREEN 

Router(config-router-af)# maximum-paths ibgp import 2 

Router(config-router-af)# end 

Related Commands

Command	Description
maximum-paths	Controls the maximum number of parallel routes an IP routing protocol can support.

neighbor activate

To enable the exchange of information with a Border Gateway Protocol (BGP) neighbor, use the neighbor activate command in address family configuration mode or router configuration mode. To disable the exchange of an address with a BGP neighbor, use the no form of this command.

neighbor {ip-address | peer-group-name | ipv6-address%} activate

no neighbor {ip-address | peer-group-name | ipv6-address%} activate

Syntax Description

ip-address	IP address of the neighboring router.
peer-group-name	Name of the BGP peer group.
ipv6-address	IPv6 address of the BGP neighbor.
%	(Optional) IPv6 link-local address identifier. This keyword needs to be added whenever a link-local IPv6 address is used outside the context of its interface.

Command Default

The exchange of addresses with BGP neighbors is enabled for the IPv4 address family. Enabling address exchange for all other address families is disabled.

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Note Address exchange for address family IPv4 is enabled by default for each BGP routing session configured with the neighbor remote-as command unless you configure the no bgp default ipv4-activate command before configuring the neighbor remote-as command, or you disable address exchange for address family IPv4 with a specific neighbor by using the no form of the neighbor activate command.

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Command Modes

Address family configuration
Router configuration

Command History

Release	Modification
11.0	This command was introduced.
12.0(5)T	Support for address family configuration mode and the IPv4 address family was added.
12.2(2)T	The ipv6-address argument and support for the IPv6 address family were added.
12.0(21)ST	This command was integrated into Cisco IOS Release 12.0(21)ST.
12.0(22)S	This command was integrated into Cisco IOS Release 12.0(22)S.
12.2(14)S	This command was integrated into Cisco IOS Release 12.2(14)S.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(25)SG	This command was integrated into Cisco IOS Release 12.2(25)SG.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SRB	The % keyword was added
12.2(33)SXH	This command was integrated into Cisco IOS Release 12.2(33)SXH.
Cisco IOS XE Release 2.1	This command was introduced on Cisco ASR 1000 Series Routers.

Usage Guidelines

Use this command to advertise address information in the form of an IP or IPv6 prefix. The address prefix information is known as Network Layer Reachability Information (NLRI) in BGP.

The % keyword is used whenever link-local IPv6 addresses are used outside the context of their interfaces. This keyword does not need to be used for non-link-local IPv6 addresses.

Examples

Address Exchange Example for Address Family vpn4

The following example shows how to enable address exchange for address family vpnv4 for all neighbors in the BGP peer group named PEPEER and for the neighbor 10.0.0.44:

Router(config)# address-family vpnv4

Router(config-router-af)# neighbor PEPEER activate

Router(config-router-af)# neighbor 10.0.0.44 activate

Router(config-router-af)# exit-address-family

Address Exchange Example for Address Family IPv4 Unicast

The following example shows how to enable address exchange for address family IPv4 unicast for all neighbors in the BGP peer group named group1 and for the BGP neighbor 172.16.1.1:

Router(config)# address-family ipv4 unicast

Router(config-router-af)# neighbor group1 activate

Router(config-router-af)# neighbor 172.16.1.1 activate

Address Exchange Example for Address Family IPv6

The following example shows how to enable address exchange for address family IPv6 for all neighbors in the BGP peer group named group2 and for the BGP neighbor 7000::2:

Router(config)# address-family ipv6

Router(config-router-af)# neighbor group2 activate

Router(config-router-af)# neighbor 7000::2 activate

Related Commands

Command	Description
address-family ipv4	Places the router in address family configuration mode for configuring routing sessions, such as BGP, that use standard IPv4 address prefixes.
address-family ipv6	Places the router in address family configuration mode for configuring routing sessions, such as BGP, that use standard IPv6 address prefixes.
address-family vpnv4	Places the router in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.
address-family vpnv6	Places the router in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv6 address prefixes.
exit-address-family	Exits from the address family submode.
neighbor remote-as	Adds an entry to the BGP or multiprotocol BGP neighbor table.

neighbor advertise-map

To install a Border Gateway Protocol (BGP) route as a locally originated route in the BGP routing table for conditional advertisement, use the neighbor advertise-map command in router configuration mode. To disable conditional advertisement, use the no form of this command.

neighbor ip-address advertise-map map-name {exist-map map-name | non-exist-map map-name}

no neighbor ip-address advertise-map map-name {exist-map map-name | non-exist-map map-name}

Syntax Description

ip-address	Specifies the IP address of the router that should receive conditional advertisements.
advertise-map map-name	Specifies the name of the route map that will be advertised if the conditions of the exist map or nonexist map are met.
exist-map map-name	Specifies the name of the route map that will be compared to the advertise map. If the condition is met and a match occurs between the advertise map and exist map, the route will be advertised. If no match occurs, then the condition is not met, and the route is withdrawn.
non-exist-map map-name	Specifies the name of the route map that will be compared to the advertise map. If the condition is met and no match occurs, the route will be advertised. If a match occurs, then the condition is not met, and the route is withdrawn.

Defaults

No default behavior or values

Command Modes

Router configuration

Command History

Release	Modification
11.1CC	This command was introduced.
11.2	This command was integrated into Cisco IOS Release 11.2.
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

Use the neighbor advertise-map router configuration command to conditionally advertise selected routes. The routes or prefixes that will be conditionally advertised are defined in 2 route-maps, an advertise map and an exist map or nonexist map. The route map associated with the exist map or nonexist map specifies the prefix that the BGP speaker will track. The route map associated with the advertise-map specifies the prefix that will be advertised to the specified neighbor when the condition is met. When configuring an exist map, the condition is met when the prefix exists in both the advertise map and the exist map. When configuring a nonexist map, the condition is met when the prefix exists in the advertise map but does not exist in the nonexist map. If the condition is not met, the route is withdrawn and conditional advertisement does not occur. All routes that may be dynamically advertised or not advertised need to exist in the BGP routing table for conditional advertisement to occur.

Examples

The following router configuration example configures BGP to conditionally advertise a prefix to the 10.2.1.1 neighbor using an exist map. If the prefix exists in MAP1 and MAP2, the condition is met and the prefix is advertised.

router bgp 5

 neighbor 10.2.1.1 advertise-map MAP1 exist-map MAP2

The following address family configuration example configures BGP to conditionally advertise a prefix to the 10.1.1.1 neighbor using a nonexist map. If the prefix exists in MAP3 but not MAP4, the condition is met and the prefix is advertised.

router bgp 5

 address-family ipv4 multicast

 neighbor 10.1.1.1 advertise-map MAP3 non-exist-map MAP4

Related Commands

Command	Description
address-family ipv4	Places the router in address family configuration mode for configuring routing sessions such as BGP, RIP, or static routing sessions that use standard IPv4 address prefixes.
address-family vpnv4	Places the router in address family configuration mode for configuring routing sessions such as BGP, RIP, or static routing sessions that use standard VPNv4 address prefixes.
route-map	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.

neighbor advertisement-interval

To set the minimum interval between the sending of BGP routing updates, use the neighbor advertisement-interval command in address family or router configuration mode. To remove an entry, use the no form of this command.

neighbor {ip-address | peer-group-name} advertisement-interval seconds

no neighbor {ip-address | peer-group-name} advertisement-interval