[c-nsp] 2950T-48 'wierdness'

[Michael Loftis]

I've a WS-C2950T-48-SI running IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), 
Version 12.1(22)EA2, RELEASE SOFTWARE (fc1)
 which is experiencing a weird problem.

The switch ports fa0/1-48 are all configured as access mode 
unconditionally.  gi0/1 is the only trunk port in the switch, yet somehow 
I've got a MAC address showing up on 6 VLANs that doesn't appear to exist 
on ANY of the hosts connected to the switch.  The MAC does not show up 
anywhere else in teh mac-address-table's of the other 5 switches, except 
the core switch (a 3750) and it ONLY sees it on the uplink port to the 
2950T...

Interestingly, it's only ever 6 matches, but the matches listed in 
positions 1 and 5 flip flop around between a couple of different ports. 
The OUI Vendor portion of the MAC address is Micro-Star International -- 
we've got primarily these vendors boxes hooked to the switch, but the MAC 
doesn't match any of the ones on the switch AFAICT, but even if it did, how 
in the world it shows up on 6 VLANs, and only 6 VLANs and there are NO 
trunks except Gi0/1, and the neighbor on that port doesn't see that MAC 
address anywhere else either.  I also checked basically every host on our 
network (certainly to include all the MSI hosts) and none of them have a 
matching MAC address.  They're all Linux boxes under our control so we can 
do that, but still, any ideas anyone?


s4#sh mac-address-table address 000c.764e.04c8
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
 207    000c.764e.04c8    DYNAMIC     Fa0/26
 205    000c.764e.04c8    DYNAMIC     Fa0/6
 206    000c.764e.04c8    DYNAMIC     Fa0/13
 220    000c.764e.04c8    DYNAMIC     Fa0/28
 208    000c.764e.04c8    DYNAMIC     Fa0/38
 209    000c.764e.04c8    DYNAMIC     Fa0/35
Total Mac Addresses for this criterion: 6


--
GPG/PGP --> 0xE736BD7E 5144 6A2D 977A 6651 DFBE 1462 E351 88B9 E736 BD7E