> On Tue, 2010-06-22 at 09:49 -0500, cisco...@secureobscure.com wrote: > > 2) OSPF timers or BFD? Currently my approach has been ospf timers of > > 1/4, its fast and seems pretty compatible with everything I have tried > > it on. All of my links are direct between routed ports so there are no > > intermediate devices that would keep a link lit after equipment > > failure. I know BFD makes sense but some of my code is old and > > linecards are flakey so I'm curious to know who has ditched low timers > > for BFD or vice versa. > > We ditched BFD in favour of low (IS-IS) timers, since 6500/Sup720 SXF > couldn't handle low BFD timers well. We're running SXI now, but haven't > changed back. We would actually like to, since some of our (leased) > amplified/DWDM links are very slow to see link down. > > Question: Is fast BFD timers a good idea on Sup720/SXI?
I would give it another try. SXF's BFD implementation was not really optimized and led to false positives.. > Another question: Is adjusting IGP timers (or using BFD) enough in an > MPLS network? How does the network invalidate allocated labels and > choosing a new LSP, disregarding FRR? Does it make sense to adjust the > holdtime or backoff timers in LDP for faster convergence? LDP's liberal retention mode basically ensures that once IGP switches to a new path, there is already a label to use. So core convergence really only depends on IGP (and failure detection). The link-up issue (where IGP/LDP sync or LDP session protection come into play) is really the only thing you need to look at when it comes to LDP in an IGP-tuned core. oli _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/