Hi Vishal,
First of all use the following command "clear arp" or "clear arp dynamic"
OK, we know the wireless controller mac address and the physical port of core switch to which the controller connected. This got to know when we used the command "show mac address-table address 88:43:e1:31:19:8b"
And also we know the IP address of wireless controller.
Now can you give command "show ip arp 172.16.10.2" on your core switch and the mac address in address resolution output must match with the mac-address which you identified physicall on your wireless controller.
If the both above command excersie success then we are sure that the wireless controller is there in the ARP table.
Please click on the correct answer on all posts if they answered your question.
Regards,
Naidu.