DHCP Leases Being Eaten - Cont...

So for the past week and a half I've had a very weird issue occurring where randomly all teh available DHCP leases in certain scopes would be eaten by *BAD_ADDRESS* followed by an invalid, 9 character MAC.

I explained how I thought I determined one of the culprits here: http://chronicgeekage.blogspot.com/2016/02/dhcp-leases-determine-what-device-is.html However it turns out this phone was not the issue.. it was actually a Lexmark printer.  I have no viewed the config yet but yesterday I discovered it after putting that unit back online.

sh cdp nei on my core switch revealed that the printer had somehow formed a routing loop.

sh cdp nei

sw4506

                 Gig 6/38          123             R S I  WS-C4506  Gig 2/26
sw4506

                 Gig 2/26          132             R S I  WS-C4506  Gig 6/38

Interface 6/38 was that printer.. forcing a shutdown then refreshing the DHCP leases page revealed my suspicions to be correct.