Unkown mac address causing problem

[cowtown]

Hello,

I have over 200 free statically assigned ip addresses that
have the same mac address mapped to them. I receive an
ip conflict message when I try to use one of the unassigned ip addresses.

Thr router is showing the following:
10.10.100.100 00e0.7b03.2ca0 fa0/1
10.10.100.101 00e0.7b03.2ca0 fa0/1
10.10.100.102 00e0.7b03.2ca0 fa0/1

10.20.100.10 00e0.7b03.2ca1 fa0/0
10.20.100.11 00e0.7b03.2ca1 fa0/0
10.20.100.12 00e0.7b03.2ca1 fa0/0

This started after the Nimda virus was released.
Is this occuring with anyone else?

Thanks,

CT

 

[ifincham]

Hi,

Seems strange.. 00-E0-7B is allocated to Bay Networks, incidentally. Can't think of much else to help at the moment I'm afraid...

Good luck anyway

 

[jimbopalmer]

Not that it HAS to be that, but my Nortel Business Policy Switch 2000 uses MAC address 00:e0:7b:cc:d1:e0 so it sure COULD be a Nortel Switch.

http://www25.nortelnetworks.com/library/csb/0109005.pdf

The one thing you can't give for your heart's desire is your heart. - Lois McMaster Bujold

 

[cowtown]

ifincham & jimbopalmer,

Thanks for your response.
I have serveral BayStack switches and CES's, but none
match that mac address. Per nortel Support there are no know issues of this type of problem.
CT

 

[evang]

Have you a Bay/Nortel switch or hub set to use bootp to get its IP address?

 

[evang]

The sequential MAC addresses suggest there's a switch or hub connected in parallel with the router.
IOW, two router ports plugged into the same layer 2 box. Is that a possibility? If so, is this intentional?

 

[evang]

Correction: the Bay/Nortel box cannot be a hub, because hubs have only one MAC address.

 

[wybnormal]

why dont you query the switch's CAM table and ARP cache to see what port the lost MAC is on? then you can chase down the cable or you might even have the port labeled ;-)

MikeS Find me at

http://www.packetattack.com

"Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin