From: Balaji Siva (bsivasub@xxxxxxxxx)
Date: Tue Aug 06 2002 - 19:30:05 GMT-3
mike, you may be running into CSCdu85211 (which is fixed only in 6.3.2)
balaji
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Kane, Christopher A.
Sent: Tuesday, August 06, 2002 6:10 PM
To: 'ccielab@groupstudy.com'
Subject: RE: IP CEF experts
I'm not a 6509 expert, but have some general questions. I'm not sure I
follow your logic in focusing on the CEF table.
What are the contents of the arp table just prior to a 'clear arp cache'?
Are there any logging events?
Do you log to syslog and if so, any pertinent info?
I recently had a client that was using another vendor's equipment for
content switching. They had a buffer overflow exploit in which the arp
buffers were running out of space. Only way to clear the problem was to
clear the arp cache. We were able to isolate by leaving a laptop plugged
into the console port of this other vendor's box thereby getting console
messages identifying the problem.
Curious to know if it could be something similar,
-chris
> -----Original Message-----
> From: Mike Schlenger [mailto:mschlenger@meridianitsolutions.com]
> Sent: Tuesday, August 06, 2002 3:42 PM
> To: 'ccielab@groupstudy.com'
> Subject: OT:IP CEF experts
>
>
> Sorry for the OT but I'm enlisting the advice of any ip cef
> experts out
> there.
>
> Problem:
> A couple times per week, a "clear arp cache" needs to be
> issued on our main
> 6509 MSFC in order to reestablish desktop/IP phone
> connectivity. It seems as
> though devices cannot communicate off of their vlan when this problem
> arises. It is strange because sometimes it affects only certain
> workstations/IP phones, and other times (like this weekend) I lost
> connectivity to an entire vlan.
> I'm going to use ping ( using the record route) next time this occurs
> because it should be a test to see if the pings work when the
> cef switching
> path is not used to route the packets. Ping -r forces packets
> to be process
> switched. Losing routing to an entire vlan or subnet can
> still be a cef
> problem as that's how the equipment stores routing and
> re-write information,
> (It uses the subnet prefix). Since cef is the switching
> mechanism on the
> sup2/msfc2 and we use the arp table to built the cef
> adjacency table, that's
> the logical place to start?
> I am very curious to see if anyone has run into something
> similar in their
> 6500 network.
>
> Again.....my apologies for the OT.
> Mike
> Michael Schlenger
> CCIE #7079
> N2N Solutions
> mschlenger@n2nsolutions.com
> 847.592.3912
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