In troubleshooting some sporadic connectivity issues at our new office, I noticed some unusual event traps in the log today.
This is a small wireless network with a single Cisco WLC-2504 controller and 4 APs. There are fewer than 15 wireless devices connected at any given time. It seems that two of the APs are showing traps every minute or so, similar to these:
Tue Sep 17 15:26:16 2013 Warning: AP with Base Radio MAC d4:8c:b5:61:11:92 has found its IP Address 184.108.40.206 being used by a machine with MAC Address 02:13:f5:70:00:00.
Tue Sep 17 15:26:05 2013 Warning: AP with Base Radio MAC 44:03:a7:f1:d4:82 has found its IP Address 0.2.146.0 being used by a machine with MAC Address 08:21:c8:20:00:00.
This seems to be interfering with connectivity for the wireless clients attached to these APs as well, causing brief disconnects.
What I find interesting is that the IP addresses listed in the traps (220.127.116.11 and 0.2.146.0) are not in any way present on our network.
Any ideas or suggestions on how I can troubleshoot and resolve these errors?