Service Manual
bgp enforce-first-as
Disable (or enable) enforce-first-as check for updates received from EBGP peers.
Syntax
bgp enforce-first-as
To turn off the default, use the no bgp enforce-first-as command.
Defaults Enabled.
Command Modes ROUTER BGP
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the 10/40GbE Switch IO Module.
Usage Information
This is enabled by default; that is, for all updates received from EBGP peers, BGP ensures that the first AS of the
first AS segment is always the AS of the peer. If not, the update is dropped and a counter is incremented. To view
the failed enforce-first-as check counter, use the show ip bgp ipv6 unicast neighbors command.
If you disable enforce-first-as, view it using the show ip protocols command.
Related Commands
show ip bgp ipv6 unicast neighbors — displays IPv6 routing information exchanged by BGP neighbors.
show ip protocols — views information on routing protocols.
bgp fast-external-fallover
Enable the fast external fallover feature, which immediately resets the BGP session if a link to a directly connected external peer fails.
Syntax
bgp fast-external-fallover
To disable fast external fallover, use the no bgp fast-external-fallover command.
Defaults Enabled.
Command Modes ROUTER BGP
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information The bgp fast-external-fallover command appears in the show config command output.
642 IPv6 Border Gateway Protocol (IPv6 BGP)