Enabling ASN capability for a BGP4+ neighbor

  1. Enter the configure terminal command to access global configuration mode.
    device# configure terminal
  2. Enter the router bgp command to enable BGP routing.
    device(config)# router bgp
  3. Enter the local-as command to configure the autonomous system number (ASN) in which your device resides.
    device(config-bgp-router)# local-as 1000
  4. Enter the neighbor capability as4 command with the enable parameter, and specify an IPv6 address, to enable 4-byte autonomous system number (ASN) capability for a specific neighbor.
    device(config-bgp-router)# neighbor 2001:db8:93e8:cc00::1 capability as4 enable

The following example enables 4-byte autonomous system number (ASN) capability for a specific BGP4+ neighbor.

device# configure terminal
device(config)# router bgp
device(config-bgp-router)# local-as 1000
device(config-bgp-router)# neighbor 2001:db8:93e8:cc00::1 capability as4 enable