Four-byte autonomous system numbers (ASNs) can be configured for a neighbor or peer-group. The following task enables 4-byte autonomous system number (ASN) capability for a 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
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