Open a web browser and go to the CIMC of the WLC using the IP address that you set for the CIMC.
You will need to logon with the username and password that was assigned to the CIMC.
Click on the toggle navigation menu in the top left corner and click on Compute.
Click on the Remote Management tab and then on the Serial over LAN tab below it.
Check the box beside Enabled
Be sure to click the Save Changes button in the bottom right corner.
Open an SSH session to the CIMC IP Address and log in.
At the CIMC prompt # type the following
CIMC# connect host