Core Issue
This problem occurs if the WLAN controller and the DHCP server are on different subnets.This is because the Wireless LAN Controller (WLC) does not do routing and it depends on a Layer 3 device for routing.
Resolution
When you configure a DHCP server to assign IP address to the Wireless Lan Clients connected to the WLAN Controller , the DHCP server should be on the same subnet as the WLAN Controller . If the DHCP server is on a different subnet, then either a router must be in place in order to route between the WLAN and the DHCP server or you can Configure the internal DHCP server on the controller witha scope for the WLAN .
For more information, refer to the DHCP Assignment section of Configuring Wireless LANs.
Problem Type
Associated but cannot pass any traffic
Products
Wireless LAN Controllers