Problems with HSRP or IOS ?

[hannes.kunz]

Hi,

i have two CISCO 3620 (IOS: c3620-is-mz.122-27.bin) connected over a switched LAN and both configured with a hsrp group.

i always receive following message:

%STANDBY-3-DUPADDR: Duplicate address 10.254.144.253 on FastEthernet0/0, source

d by 0000.0c07.ac01

the ip address in the error-message is the routers own ip adress of the lan interface

it seems to be the same problem which is documented on CCO:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094afd.shtml#t12

in the document the message may be due SPT loops...

but if i connect the both routers directly with a cross-over cable the message appears again.

so it can´t be a problem of the switched LAN (SPT or something else..)

another strange thing:

when i execute a "show cdp neighbor neighbor" on Router A then i see Router A appearing as the neighbor !!

The router sees itself in the cdp table ?!

Is this a IOS bug ?

any ideas.

thx

hannes

[alagrawa]

Hi Hannes,

Your symptoms definitely looks like a bug. Both CDP and HSRP use multicast. It looks like multicast packets are being looped back on fas0/0. Are you able to ping from one router to the other without any issues?

I did a quick bug search but havent found anything. I am aware of a bug CSCef13690 which causes multicast and broadcast traffic to get looped back if a port on the NM-2FE2W-V2 etherswitch module is configured as 10/half.

If noone else responds, I would recommend opening a case with TAC to get a bug identified.

regards

-Alok