You might want to look up the following document on CCO:
Avoiding HSRP Instability in a Switching Environment with Various Routing
Platforms.
Looks like www.cisco.com/warp/public/619/8.shtml
> -----Original Message-----
> From: John Starta [mailto:john@xxxxxxxxxx]
> Sent: Tuesday, February 25, 2003 1:12 PM
> To: cisco@xxxxxxxxxxxxxx
> Subject: HSRP or switch issue? [7:63768]
>
>
> I'm currently experiencing an oddity with multicast traffic
> like HSRP that
> I'm looking for some ideas on. For simplicity the network
> design consists
> of 2 Cisco 3640 routers running HSRP between them connected
> to a single
> Extreme [Black Diamond] switch. Basically...
>
> extreme switch
> | |
> | |
> rtr1 rtr2
>
> Normally everything works just fine, but periodically -- in time, not
> quantity -- HSRP indicates via the %HSRP-4-DUPADDR message
> that I have a
> duplicate [IP] address. (The quantity of the messages indicating the
> duplicate IP address ranges from half dozen to nearly a
> hundred. The time
> between messages closely matches the HSRP HELLO interval.)
>
> When I receive these messages, on the active HSRP router for
> instance, they
> indicate the duplicate address as being the physical
> interface IP address
> of the active HSRP router with the source MAC address as the
> virtual MAC
> [address] of the active HSRP router. Receipt of these %HSRP-4-DUPADDR
> messages indicating the duplicate as itself suggests an issue with
> multicast -- a loop of sorts whereby the switch copies the multicast
> announcement [back] to the same switch port it originated.
> Keep in mind
> that there are no interface or HSRP state changes so the
> messages probably
> aren't coming from the standby HSRP router. (Especially since
> the indicated
> duplicate IP address is that of the physical interface on the
> active HSRP
> router, not the virtual IP.)
>
> I did some poking around on Extreme's web site and they
> indicate an issue
> with HSRP in an earlier version of code, but that is/was fixed in the
> version being used.
>
> Have anybody run into this before? Ideas regarding cause? I
> don't have
> access to the switch since it belongs to the customer.
>
> .,
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=63784&t=63768
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to abuse@xxxxxxxxxxxxxx
