I am troubleshooting a dual 4404-100 WLAN controller implementation. The two controllers have all 4 ports connected to two 6509 core switches using 4 ap-manager interfaces. I have checked every step between the controller and the DHCP servers I can think of, including:
1. DHCP server address on the WLAN VLANs
2. ip-helper address on L3 interfaces on the switches
3. DHCP server address on the ap-manager interfaces
4. APs are using spanning-tree portfast
5. DHCP server is reachable from the controller and access ports
I am getting feedback from users that DHCP works inconsistently, and sometimes on 2 of 3 WLANs but not the third. I honestly cannot think of any configuration issues. I was considering turning off DHCP relay and allowing the DHCP requests to be bridged to the wired network as I have ip-helper address configured on the L3 interfaces that the APs are on.