When running through the initial configuration of my new Cisco Wireless LAN Controller (WLC), I unknowingly left my management vlan id untagged. Once I racked and patched the WLC on the corporate network to continue configuration I was not able to reach it, couldn’t even ping it. To get access to the WLC I added this to the trunk port configured for the controller
Switch(config-if)# switchport trunk native vlan VLANX
(where VLANX is the vlan in which the management IP address you configured for your WLC resides.)
Upon doing this you should be able to access your WLC via ICMP and HTTP
