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Cisco WLAN Controller - IP address being used by another machine

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 3.118.234.188 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 (3.118.234.188 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?
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djcanter
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Is LAG enabled on the controller & you've connected more than one port from your controller to different switches?
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Yep it's as simple as a duplicate IP.
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gwermter

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After testing, the duplicate ip address on the access point was the issue and fixing it resolved the problem.