Switch one interface is showing 2 MAC Addree - Any reason?

[Mahinmitrxblr]

We have an interesting issue. 6509A - is showing two mac-addresses on g6/45

6509A#sh mac-address-table int g4/45

Legend: * - primary entry

vlan mac address type learn ports

------+----------------+--------+-----+--------------------------

* 9 0011.2540.7d86 dynamic Yes Gi4/45 ---- this is atl903 172.18.1.102- which is a physical box that keeps rebooting itself.

* 9 0011.2540.e96d dynamic Yes Gi4/45

[dtochilovsky]

Is there is a switch/hub plugged in to that port Gi4/45, that has two devices connected to it?

[cisco_lad2004]

does this box have a virtual interface ?

[nate-miller]

We had a problem with some IBM boxes where the onboard NIC and the ILO port (console port, management port, whatever) share an asic. For some reason, MAC addresses for the ILO port were leaking out on the physical interface. I believe that firmware/bios updates cleared that problem.

If you can get into that server, see if you can find that MAC address as belonging to some interface on that nic.