About BGP configuration in ASR 1000

[Kumaresan Chinnasamy]

Please help someone,

I have executed the below command on ASR 1000 router and there are 2 things happened. 1.This command removed all the BGP configuration associated to that peer IP on a router, 2. Same command we have executed another ASR 1000 router and it removed partial config associated to that peer IP.

router bgp xxxx

no neighbor x.x.x.x remote-as xxxx shutdown

Note: We have executed the same command on other series routers and nothing happened.

Please advise.

[Martin Hruby · Accepted solution]

Dear Kumaresan

The shutdown keyword is optional when configuring a BGP peer, it will prevent the BGP process from trying to establish a session while you're still implementing other peer configurations. Notice when configuring a new BGP peer with neighbor 1.2.3.4 remote-as 65000 shutdown it actually creates two separate commands on the IOS-XE:

router bgp 65001
 neighbor 1.2.3.4 remote-as 65000
 neighbor 1.2.3.4 shutdown

When you want to re-enable this peer, just configure no neighbor 1.2.3.4 shutdown because if you include the remote-as option in there (e.g. no neighbor 1.2.3.4 remote-as 65000 shutdown) it will ignore the shutdown keyword and remove the peer altogether. This is because in the "no" form of the neighbor 1.2.3.4 remote-as 65000 command, the shutdown keyword is not implemented as an option.

Best regards,
Martin

[Peter Paluch]

Hi Martin,

Nice one!

Best regards,
Peter

[Kumaresan Chinnasamy]

Thansk Martin,

When we give extra keyword it should give error but in this case we did not get error and it removed whole config, is it depends on IOS?

Same command when we give on regular IOS it is not removing any config associated with BGP