How to Assign or Enable IPv6 on a cPanel account

Question

What do I need to do to get IPv6 functionality for my cPanel accounts?

Answer

1. Verify that IPv6 is functioning on your server.
2. Log into WHM as the ‘root’ user.
3. Navigate to "Home / IP Functions / IPv6 Ranges."
4. Click the "Add Range" button.
5. Enter a name for the IP range in the "Range Name" textbox.
6. Enter the IPv6 range in the "Range" textbox. 
7. Click the "Add Range" button.
8. Navigate to "Home /IP Functions / Assign IPv6 Address."
9. Select the account to assign an IPv6 address.
10. Select the range to which the IPv6 address will be assigned from the "Enable this account with an IPv6 address from the selected range" dropdown menu.
11. Click the "Enable Account" button.

CPANEL_WARN: If you are using cPanel 126 or earlier, during step 6 do not add an IPv6 address range containing the shared IPv6 address you set in the "Basic WebHost Manager Setup" interface. You must add your gateway individually before you add the full gateway range and set the gateway to "RESERVED" so that the system does not assign this IP address to an account.
This restriction does not apply to versions 128 or later.

Additional resources

IPv6 Server Administration

IPv6 Ranges

Guide to IPv6

Troubleshoot IPv6 Problems

How to Get Started With IPv6

Assign IPv6 Address