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Re: AT&T NYC

  • From: Petri Helenius
  • Date: Mon Sep 02 14:44:19 2002

"Stephen J. Wilcox" wrote:
> but.. with SPF you need to run the algorithm on all paths for each flap and then
> see what that does to your routes
> 
Only the paths that cross the one you lost. Obviously if this happens
or not, depends on your implementation. Look in the documentation under
heading "partial SPF".

> with eigrp you only need to apply the algorithm to any route on the link that
> flapped and then only on the attached router (which will propogate much like bgp
> if it requires other routers to recalculate)

For this you need to look under the heading "non-technical marketing propaganda". 

So far, I've yet to figure out a real life network example where 
EIGRP would outperform either OSPF or IS-IS. Obviously if you compare 
an ancient OSPF implementation to a more recent implementation of another
protocol, differences in performance can be found. Objective measurements 
are hard to come by.
> 
> yes thats bad if yuo have 100000 routes but you shouldnt have! assuming a
> smaller routing table yuo get quicker convergence and much much less CPU
> requirement on your rotuers
> 
Most networks have more routes than they have links or routers. This already
by the nature that most links have one route. So the assumption that 
number of routes would be small is usually incorrect. Obviously if you're talking
about <50 routes, choice of routing protocol does not make a difference and you'd
be probably happy running RIPv2.

Pete