Strange log entry on WLC5508?

Question

following log entry on a WLC5508 (7.4.100.0) is permanentely filling up the log buffer and the WLC operates in low performance.
*spamApTask7: Oct 29 10:08:13.114: #LWAPP-3-DUP_AP_IP: spam_lrad.c:33673 Duplicate IP address detected for AP APb0fa.eb3d.8b4f, IP address of AP  0.2.146.0, this is a duplicate of IP on another machine (MAC address  4:ba:53:e0: 0: 0)
*spamApTask0: Oct 29 10:08:04.478: #LWAPP-3-DUP_AP_IP: spam_lrad.c:33673 Duplicate IP address detected for AP APb0fa.ebb8.de74, IP address of AP  0.2.146.0, this is a duplicate of IP on another machine (MAC address  4:b9:c8: 0: 0: 0)
*spamApTask7: Oct 29 10:07:43.113: #LWAPP-3-DUP_AP_IP: spam_lrad.c:33673 Duplicate IP address detected for AP APb0fa.eb3d.8b4f, IP address of AP  0.2.146.0, this is a duplicate of IP on another machine (MAC address  4:ba:53:e0: 0: 0)
*spamApTask0: Oct 29 10:07:34.477: #LWAPP-3-DUP_AP_IP: spam_lrad.c:33673 Duplicate IP address detected for AP APb0fa.ebb8.de74, IP address of AP  0.2.146.0, this is a duplicate of IP on another machine (MAC address  4:b9:c8: 0: 0: 0)
Has somebody an idea what the issue is or can be? Or has it been monitored from someone else on other installations as well?
Both AP's does have different IP adresses from DHCP server x.y.z.248 and x.y.z.249. WLC is working as internal DHCP server. DHCP proxy is disabled. From what could this strange address 0.2.146.0 come from? I've never seen such an address like 0.2.146.0
I would like to appriciate any kind of help or suggestions
thanks a lot
Klaus

Answer 1

This is another common issue that is seen when the AP tries to join the  WLC. You might see this error message when the AP tries to join the  controller.
     No more AP manager IP addresses remain
One of the reasons for this error message is when there is a duplicate  IP address on the network that matches the AP manager IP address. In  such a case, the LAP keeps power cycling and cannot join the controller.
The debugs will show that the WLC receives LWAPP discovery requests from  the APs and transmits a LWAPP discovery response to the APs. However,  WLCs do not receive LWAPP join requests from the APs.
In order to troubleshoot this issue, ping the AP manager from a wired  host on the same IP subnet as the AP manager. Then, check the ARP cache.  If a duplicate IP address is found, remove the device with the  duplicate IP address or change the IP address on the device so that it  has a unique IP address on the network.
The AP can then join the WLC.