Show BGP peer data when session is down?

[Lars-Johan Liman]

Hello, Ondrej,

Sorry for the late reply. I've been on a very long vacation.

santiago at crfreenet.org:
> On Wed, Jun 29, 2011 at 05:08:40PM +0200, Lars-Johan Liman wrote:
>> If you have an established BGP session, you can find out a lot of the
>> session details using
>> 
>> # birdc show protocols all <bgp_proto_id>
>> 
>> Specifically, you can look at
>> 
>> BGP state:		...
>> Session:		...
>> Neighbor AS:	...
>> Neighbor ID:	...
>> Neighbor address:	...
>> Nexthop address:	...
>> Source address:	...
>> Neighbor caps:	...
>> Route limit:	...
>> Hold timer:		...
>> Keepalive timer:	...
>> 
>> Now, if the session is terminated for one reason or another, the info
>> disappears.
>> 
>> BGP state:		Passive
>> Last error:		Received: Administrative shutdown
>> 
>> and that's it.
>> 
>> This makes it very hard to create scripts that keep an eye on specific
>> peering sessions based on the identity (remote IP address) of the
>> peer, because once the session is down, you can no longer find it,
>> because the IP address is nowhere in the output. :-P

> Hello

> Generally, the protocols are supposed to be identified by their names,
> so we usually do not print 'static' information which is directly
> from config files.

> But as it seems that this is requested feature, we could change some of
> output that is available only when the session is to be available all
> times. Some of these values can be easily avaliable all times (like
> Neighbor ASN and address), some are complicated (like Nexthop address
> and Session) and some are dynamic and unavailable when off (like
> Neighbor ID or timers)

> I would prefer to make available just 'Neighbor AS' and 'Neighbor
> address' fields. Perhaps 'Session' too. Is this sufficient for
> your purposes?

It is indeed. That way I can trigger my monitoring system on useful
input, and keep track of sessions that have "disappeared".

It would be very much appreciated if you could make that change in a
future release.

				Best regards,
				  /Liman