BGP Support for 4-byte ASN
Cisco IOS XE Release 2.3
Cisco IOS XE Release 2.4
Cisco IOS XE Release 3.1.0SG
Cisco IOS XE Release 3.3SG
The BGP Support for 4-Byte ASN feature introduced support for 4-byte autonomous system numbers.
In Cisco IOS XE Release 2.4 and later releases, the Cisco implementation of 4-byte autonomous system numbers uses asplain as the default regular expression match and output display format for autonomous system numbers, but you can configure 4-byte autonomous system numbers in both the asplain format and the asdot format as described in RFC 5396. To change the default regular expression match and output display of 4-byte autonomous system numbers to asdot format, use the bgp asnotation dot command.
The following commands were introduced or modified by this feature: bgp asnotation dot, bgp confederation identifier, bgp confederation peers, all clear ip bgpcommands that configure an autonomous system number, ip as-path access-list, ip extcommunity-list, match source-protocol, neighbor local-as, neighbor remote-as, redistribute (IP), router bgp, route-target, set as-path, set extcommunity, set origin, all show ip bgp commands that display an autonomous system number, and show ip extcommunity-list.