Administrator Guide

Layer 3 Routing Commands 1258
Default Configuration
No subnets are associated with a BGP listen subnet range, and the BGP
dynamic neighbor feature is not activated.
Command Mode
BGP Router Configuration mode, IPv4 Address Family Configuration mode,
IPv6 Address Family Configuration mode
User Guidelines
This command can be used to configure IPv4 BGP neighbors (BGP Router
Configuration mode) as well as IPv6 BGP neighbors (IPv6 Address Family
Configuration mode).
Use the limit keyword and max-number argument to define the global
maximum number of IPv4 BGP dynamic neighbors that can be created.
BGP dynamic neighbors are configured using a range of IP addresses. Each
range can be configured as a subnet IP address. After a subnet range is
configured for a BGP peer group, and a TCP session is initiated by the
neighbor for an IP address in the subnet range, a new BGP neighbor is
dynamically configured on the local switch. Dynamically created neighbors
are not displayed in the running-config.
It is acceptable that the template peer name is not specified. In this case, all
dynamic neighbors are created with the default parameters. The template
peer name can be assigned/changed for a listen range at any time.
The limit on the total number of both IPv4 and IPv6 listen range groups is 10.
Command History
Introduced in version 6.3.0.1 firmware.
Example
The following example shows how to create an IPv4 listen range with a
template to be inherited with dynamically created BGP neighbors:
console#configure
console(config)# router bgp 100
console(config-router)#bgp listen limit 10
console(config-router)#bgp listen range 10.12.0.0/16
console(config-router)#bgp listen range 10.27.0.0/16 inherit peer ABC