You can set a global limit on the number
of dynamic BGP4 neighbors, create a BGP4 peer group, and associate a subnet range with the
peer group.
About this task
The peer group is added to the BGP neighbor table of the local device and an
alternate ASN is configured.
Procedure
-
Access global configuration
mode.
device# configure terminal
-
Access BGP configuration mode.
device(config)# router bgp
-
Specify the autonomous system in
which your device resides.
device(config-bgp-router)# local-as 65520
-
Create a peer group.
device(config-bgp-router)# neighbor mypeergroup1 peer-group
This example creates a peer group called mypeergroup1.
-
Specify an autonomous system for
the peer-group.
device(config-bgp-router)# neighbor mypeergroup1 remote-as 80
-
Associate a subnet range with
the BGP peer group.
device(config-bgp-router)# listen-range 150.1.0.0/16 peer-group mypeergroup1 limit 20
This example specifies the 150.1.0.0/16 subnet range and uses the
limit keyword to set the maximum number of BGP dynamic
neighbors that can be created.
-
Specify an alternate autonomous
system for listen range neighbors in the configured peer group.
device(config-bgp-router)# neighbor mypeergroup1 alternate-as add 101
Example
The following example summarizes the commands in
this procedure.
device# configure terminal
device(config)# router bgp
device(config-bgp-router)# local-as 65520
device(config-bgp-router)# neighbor mypeergroup1 peer-group
device(config-bgp-router)# neighbor mypeergroup1 remote-as 80
device(config-bgp-router)# listen-range 150.1.0.0/16 peer-group mypeergroup1 limit 20
device(config-bgp-router)# neighbor mypeergroup1 alternate-as add 101
