From: Tom Lijnse (Tom.Lijnse@globalknowledge.nl)
Date: Mon Jun 06 2005 - 04:20:24 GMT-3
Hi Tim,
This document:
http://www.cisco.com/en/US/tech/tk827/tk831/technologies_tech_note09186a
0080094806.shtml
points out some useful commands to troubleshoot CEF load balancing.
You can use 'sh ip cef exact-route <source-ip> <destination-ip>
internal' to see how traffic is distributed for certain
source-destination pairs.
You can use 'sh ip cef <prefix> internal' to see the internal load
balancing structures for a prefix. Turning on 'ip cef accounting
load-balance' could then yield some information on which hash-buckets
are being used.
I hope this helps you dig a little deeper into the problem, though I am
not sure if it will actually solve it as it looks like it should just
work.
Regards,
Tom Lijnse
CCIE #11031
Global Knowledge
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Tim.Bonnell@argosy.com
Sent: vrijdag 3 juni 2005 23:01
To: ccielab@groupstudy.com
Subject: load balancing problem
We have an issue that seems to have no resolution.
We have a 7513 and 3640 connected using 2 T1 serial links. EIGRP, IP
CEF per destination load sharing, and LLQ for voice traffic are
configured. The EIGRP metrics indicate that the links are indeed equal.
LAN traffic behind the 7513 going to the LAN behind the 3640 seems to be
load balance, within reason. LAN traffic behind the 3640 going to the
LAN behind the 7513 favors one of the links 90% of the time. So the
traffic is not load sharing like it should.
Routing and CEF tables look fine. Just can't find an explanation as why
the traffic is favoring only one of the links.
Opened TAC case - but they said it should be working and are researching
the issue.
Ever see anything like this before? Any troubleshooting commands that
would help identify the cause?
Thanks,
Tim
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