Mark Tinka <mailto:[EMAIL PROTECTED]> wrote on Monday, September 29, 2008 7:51 AM:
> On Monday 29 September 2008 12:50:08 Oliver Boehmer > (oboehmer) wrote: > >> I've never really figured out what the backup routes in >> ISIS are good for exactly (haven't digged deep into this >> either), and I don't bother as you can achieve fast >> convergence either way by tuning the SPF- and/or >> PRC-interval down. So either topology is able to converge >> equally fast. > > In relation to this, I've posted (on my blog) IS-IS > configurations I think are optimized for my environment > (and perhaps, a few others): > > http://aknit-routing.blogspot.com/2008/06/is-is-routing-protocol-best-pr actices.html > > Feel free to gnaw at it and throw any comments. a few comments after taking a quick look: SPF and PRC-interval are quite aggressive. 1 msec initial wait is appropriate for single link failures, but if you have multiple failures within a short time frame (for example SRLG- or node-failures), you might need to run two SPFs, so many deployments use 50ms initial wait. 20 msec interval is quite low, some folks' SPF takes much longer than this. So I would consider increasing this. Same reasoning applies to lsp-gen-interval, for SRLG failures you might need to generate two LSPs. Not sure if I would consider "ignore-attached-bit" a Best Practice.. It is useful in some environments, but many others would rely on it. "log-adjacency-changes all" generates some more log files (for example adjacency down when you shut an interface).. AS you tune for fast convergence, "process-max-time 50" and "ip routing protocol purge interface" (or "ip slow-converge" in non-12.0S/non-12.2S trains) would also be recommended. oli _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
