In a message written on Tue, Nov 08, 2011 at 04:22:48PM -0500, Christopher Morrow wrote:
I think actually it wouldn't have caused more validation requests, the routers have (in some form of the plan) a cache from their local cache, they use this for origin validation... there's not a requirement to refresh up the entire chain. (I think).
I kinda think everyone is wrong here, but Chris is closer to accurate. :P When a router goes boom, the rest of the routers recalculate around it. Generally speaking all of the routers will have already had a route with the same origin, and thus have hopefully cached a lookup of the origin. However, that lookup might have been done days/weeks/months ago, in a stable network. While I'm not familar with the nitty gritty details here, caches expire for various reasons. The mere act of the route changing paths, if it moved to a device with a stale cache, would trigger a new lookup, right? Basically I would expect any routing change to generate a set of new lookups proportial to the cache expiration rules. What am I missing? -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/