A difference between the IP address defined in the Simple Network Management Protocol (SNMP) community of the Wireless LAN Controller (WLC) and the IP address of the Wireless Control System (WCS)
A problem with the Dynamic Host Configuration Protocol (DHCP) server on the access point (AP) manager interface
In order to resolve this problem, review these steps:-
The IP address defined in the SNMP community of the WLC must be the IP address of the WCS, not the IP address of the WLC. The IP address 0.0.0.0 works. In order to tighten security, specify the IP address of the WCS in the SNMP community string of the WLC. Once the IP address of the WLC in the SNMP community string is configured, change the IP address in the SNMP community string to 0.0.0.0. If the WCS and the WLC still do not communicate, reboot the WLC.
Sometimes the issue is with the DHCP server on the AP-manager interface. Delete a controller from the WCS, then go into the controller and add a secondary DHCP address on the AP-manager interface. Save and reboot. Re-add the controller to the WCS .
Reset the controller back to the factory default settings.
Note: This erases the configuration and all data.
Wireless LAN Controllers
Wireless Control System
Device Access Method
Wireless Devices Errors, Warnings, Statistics and Log Messages