This is for CentOS/RHEL based servers.
Steps in WHM: Log into WHM and go to Basic cPanel & WHM Setup.
Change the Primary IP here with the option that says “The IP address (only one address) that will be used for setting up shared IP virtual hosts”
Log in to SSH, and do the following:
Change the IPADDR and GATEWAY lines to match the new IP and Gateway for the new ip
Change the GATEWAY line here if it does not exist in the ifcfg-* file.
Remove the new primary IP from this file if it is present
Add the old primary IP to this file with the format
<IP address>:<Net Mask>:<Gateway>
Replace the old primary IP with the new primary IP
Replace the old primary IP with the new one if needed. The hostname’s dns will need to be updated too
Restart the network service to make the new IP the primary
# service network restart
Note: You’re probably going to be disconnected at this point, and have to log in to ssh using the new primary ip.
Restart the ipaliases script to bring up the additional IPs
# service ipaliases restart
Run ifconfig and make sure all IPs show up correctly
Update the cpanel license to the new primary IP
Verify you can still log in to WHM and there is no license warning