Interesting Mac Address Flap issue

[Jagdwulfe]

Hello all, I have an interesting little mac address flapping issue. To set this up I will explain how the network is set up. Basically it is a hub and spoke with each access switch having two trunks back to the core. Spanning tree is blocking on one port and forwarding on the other. Here is the issue; I have a mac address that is flapping however unlike a normal mac flap where you can pretty much narrow it down to a switch by working your way along using cdp neighbors and show mac this address is rotating around the ports connected to the core. When you go the access switch it shows the mac coming from the core. Not seeing any pattern from the rotation of the flaps either.

[Amit Verma]

This MAC address is belongs to a server(Physical or virtual) or switch?

[Jagdwulfe]

That is just it, a OIU look up says it is a xerox machine. There are two servers on the core with dual nics but I verified their macs. I am going to have to go over to the site and do a packet capture and see what is going on. Figured I would ask if anyone else experienced this before.

[Ganesh Hariharan]

That is just it, a OIU look up says it is a xerox machine. There are two servers on the core with dual nics but I verified their macs. I am going to have to go over to the site and do a packet capture and see what is going on. Figured I would ask if anyone else experienced this before.

Hello,

If the servers are connected with dual NIC, Check the teaming configuration at server level if they are Active-Active then both the NIC will come into picture.

Try configuring Active-Passive and make the mac comes from single NIC for troubleshooting.

Hope it Helps..

-GI