[c-nsp] Graceful way to terminate BGP Session

[Justin M. Streiner]

On Fri, 22 Jun 2007, Voll, Scott wrote:

> We are going to terminate one of the former ISP BGP sessions.  Is there
> a way to do this gracefully without causing all sorts of routing issues?
> I'm thinking shutting down the Gig port is not my best option.  Do I
> just remove the BGP Neighbor?  Will that cause me issues also?

You can shut the BGP neighbor down.  It's possible that things may take a 
sub-optimal path when you shut the neighbor down because the BGP router 
process will have to re-compute the best paths for each prefix you're 
receiving from your other two neighbors.  My experience has always been 
that the service impact from doing this is quite low, to the point where 
most people wouldn't even notice.  As always, YMMV :)

Also, if you shut the session down, rather than the interface connected to 
the neighbor you're removing, your logs will show something similar to 
"BGP neighbor x.x.x.x administratively shut down" rather than "BGP 
neighbor x.x.x.x down" - it's just cleaner.  Once you're satisfied that 
everything's fine, you can delete the neighbor and tear down the interface 
at your leisure.

jms