[c-nsp] IS-IS LSP Generation/Expiry + Database Optimization - Issue

[Oliver Boehmer (oboehmer)]

Mark Tinka <> wrote on Sunday, February 22, 2009 06:57:

[..]
> In our experience using 'max-lsp-lifetime 65535' and 'lsp-
> refresh-interval 65000' as encouraged, we have encountered a
> couple of issues as regards recovering/restarting routers,
> and wonder whether this is a bug or feature as part of IOS's
> implementation of the IS-IS protocol.
> 
> We have seen that routers that return to operational status
> (either from a software crash or normal reload) may have
> some of their v4/v6 Loopback addresses not present in the
> IS-IS routing tables of the other routers in the network.
> This would lead to failure of iBGP to establish.
[..]
> We are wondering whether this is a function of the 'max-lsp-
> lifetime' and 'lsp-refresh-interval' features we have
> enabled, or whether this is a bug.

I've "worked" with the increased lifetime/refresh intervals in several
large networks for the last 8 years, and I've not seen an issue with it.
Do you have any indication that the problem you've been experiencing is
caused by "corrupt" LSPs? It is strange that you only seem to see the
problem on some routers, and not on others, which makes a "corrupt" LSP
advertised by the restarting router a bit unlikely..

I would still recommend the higher lifetime values, however the original
reason (reducing the "chatter") is certainly much less important these
days with high-speed CPU and links, so I'm not passionate about it..

	oli