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question about traffic eng/ Cisco CEF.

daemon@ATHENA.MIT.EDU (Jaideep Chandrashekar)
Tue Aug 8 16:49:09 2000

Date: Tue, 8 Aug 2000 15:47:20 -0500 (CDT)
From: Jaideep Chandrashekar <jaideepc@cs.umn.edu>
To: nanog@merit.edu
Message-ID: <Pine.SOL.4.21.0008081545420.22522-100000@plato.cs.umn.edu>
MIME-Version: 1.0
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Errors-To: owner-nanog-outgoing@merit.edu


Hi,
  I seem to be having some problems trying to use Cisco CEF on a 7200.
My problem description is as follows.

I need some way of sharing load (connections) across multiple links. The
routes are all statically configured and have the same distance (though
physically of different lengths).

When I enable cef and set it to share load on a per destination mode, for
some reason, all the traffic to a destination takes a single route
.. though the route table shows two equal cost paths.

The only point I might be missing is that I am looking at very few
connections (2-3) and that load sharing with cef might be engineered to
share load in a statistical sense (only kick in with large number of
connections).

Could anybody throw any light on this.


Also ... is there any way to clear the routing table so that when a new
link comes up, (and a new route is added to a list of equal cost
paths)  all the connections are again redistributed across the 
links. Couldn't seem to be able to make existing connections switch
paths. With fast switching ... was able to do this by flushing the
routecache .. but cef doesn't use a cache (says the documentation)....


Any help is much appreciated.


-jaideep





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