[c-nsp] arps and "it's our address" ?

[Tuc at T-B-O-H.NET]

Hi,

	Posting this on behalf of someone else. 

	About 2 nites ago, around midnight, his network seemed like it imploded.
Its a WISP, and connected to GigabitEthernet0/1 is his "Site A" that is 
192.168.25.1/24 . About 60% of the devices off the AP aren't contactable anymore.
He has GigabitEthernet1/1 that he hangs 192.168.50.1/24 (Site B) and 
192.168.75.1/24 (Site C). Site B seemed to get a ripple effect for a few minutes,
but recovered. Site C didn't get touched at all.

	Later that night, one of this backhauls still was able to pass data, but
you couldn't contact the device management for 4 hours.

	He did a bunch of re-terminating, re-cabling, replacing equipment and
it seems to still be plaguing him. He's also said he'll plug something in, be
able to contact it for 2 minutes, then it disappears.

	He did a "debug arp" and found this :

002005: .Jun  9 10:44:12.348 EDT: IP ARP: creating incomplete entry for IP address: 192.168.25.2 interface GigabitEthernet0/1
002006: .Jun  9 10:44:12.348 EDT: IP ARP: sent req src 192.168.25.1 0016.9d4e.9861,
                 dst 192.168.25.2 0000.0000.0000 GigabitEthernet0/1
002007: .Jun  9 10:44:12.348 EDT: IP ARP req filtered src 192.168.25.1 0016.9d4e.9861, dst 192.168.25.2 0000.0000.0000 it's our address
002008: .Jun  9 10:44:14.348 EDT: IP ARP: sent req src 192.168.25.1 0016.9d4e.9861,
                 dst 192.168.25.2 0000.0000.0000 GigabitEthernet0/1
002009: .Jun  9 10:44:14.348 EDT: IP ARP req filtered src 192.168.25.1 0016.9d4e.9861, dst 192.168.25.2 0000.0000.0000 it's our address
002012: .Jun  9 10:44:16.348 EDT: IP ARP: sent req src 192.168.25.1 0016.9d4e.9861,
                 dst 192.168.25.2 0000.0000.0000 GigabitEthernet0/1
002013: .Jun  9 10:44:16.348 EDT: IP ARP req filtered src 192.168.25.1 0016.9d4e.9861, dst 192.168.25.2 0000.0000.0000 it's our address
002018: .Jun  9 10:44:18.348 EDT: IP ARP: sent req src 192.168.25.1 0016.9d4e.9861,
                 dst 192.168.25.2 0000.0000.0000 GigabitEthernet0/1
002019: .Jun  9 10:44:18.348 EDT: IP ARP req filtered src 192.168.25.1 0016.9d4e.9861, dst 192.168.25.2 0000.0000.0000 it's our address

002022: .Jun  9 10:44:20.348 EDT: IP ARP: sent req src 192.168.25.1 0016.9d4e.9861,
                 dst 192.168.25.2 0000.0000.0000 GigabitEthernet0/1
002023: .Jun  9 10:44:20.348 EDT: IP ARP req filtered src 192.168.25.1 0016.9d4e.9861, dst 192.168.25.2 0000.0000.0000 it's our address

	He wanted me to post this and ask if anyone has an idea why its saying that.
Googles lead him to believe there is a MAC address duplication somewhere.

			Thanks, Tuc