How to Configure Multiple shared IP’s in WHM

You can’t add multiple shared IPs in WHM GUI, but it’s possible to do so via SSH (login as root).
First, you need to create a /var/cpanel/mainips/ directory, if it doesn’t exist:

# mkdir /var/cpanel/mainips/

Then, create a /var/cpanel/mainips/root file, with all the Ips as folllows

10.0.0.10
10.0.0.12

Basically, each line is an additional shared IP in WHM. That’s it!
You can verify from WHM>>Home>>IP Functions>>Show/Edit Reserved IPs