[c-nsp] BGP ghosts in 12.2(25)S5

[Bernhard Schmidt]

On 2005-09-19, Bernhard Schmidt <berni at birkenwald.de> wrote:

>> How can this happen? To my knowledge, if the same neighbor sends you a 
>> new path for an already known prefix the old one is implicitly withdrawn.
>> I think those issues started in S5, I can't remember having them in S4.
> Correction, I didn't use S4 on those routers. The old version was S3
> which was running since it was released, I don't recall similar
> problems.

I have tracked down the issue to soft-reconfiguration. I disabled it on
one router and it became perfectly stable, while the other one had four
ghosted prefixes (seen by the router, but not sent by the upstreams
anymore) and more than a dozen of prefixes with weird entries in the
available paths (so ghosting for sure when the prefix is withdrawn). All
those numbers in less than eight hours.

Is this a known issue?

Bernhard