SOLVED Basic WebHost Manager® Setup - shared IPv6 error

[ZZPlab]

I'm having this issue now on multiple servers:

I have IPv6 enabled en setup and changed nothing. Before IPv6 was ok and working fine, no errors. Just since 1-2 weeks or so, opening the basic setup gives this error:
WHM > Basic WebHost Manager® Setup:
* The IPv6 address (only one address) to use to set up shared IPv6 virtual hosts.
You must enter a valid IPv6 address that you have bound to this server.

/etc/sysconfig/network-scripts/ifcfg-eth0
IPV6INIT=yes
IPV6_AUTOCONF=no
IPV6_DEFROUTE=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_FAILURE_FATAL=no
IPV6ADDR=2xxx:xxxx:xxxx:xxxx:1111::1/64
IPV6_DEFAULTGW=2xxx:xxxx:xxxx:xxxx::1

In WHM > IPv6 Address Ranges this is added and available:
2xxx:xxxx:xxxx:xxxx:1111::/112

When trying to modify the IPv6 on a vps where the IPv6 field is empty, I cannot change or add anything:
WHM > Basic WebHost Manager® Setup:
Invalid Shared Virtual Host IPv6 Address value: “2xxx:xxxx:xxxx:xxxx:1111::0001”. This setting will not be updated.

Is this a WHM bug?

 

[cPanelMichael]

Hello,

Can you verify the shared IPv6 address you are attempting to configure does not overlap with an existing IPv6 range configured on the server? This is not permitted as of cPanel version 68 as it can break IPv6 configurations:

Fixed case CPANEL-15367: Prevent overlapping shared IPv6 with enabled ranges.

Thank you.

 

[ZZPlab]

Thanks for the respons.
I tried:
- Enabled ipv6 ranges being empty and then first adding the shared ipv6. That should always work I assume..?
- Adding a shared overlapping the enabled range.
- Adding a shared NOT overlapping the enabled range.

The shared ipv6 I try to add is within the /64 range configured in /etc/sysconfig/network-scripts/ifcfg-eth0, but that is how it should be, right?

Do I need to restart anything in between?

Can I leave the shared ipv6 empty and just work with an enabled range and assign ipv6 to domains/accounts?
Or do I need a shared IP for the server to work properly?

 

[cPanelMichael]

Hello,

The shared ipv6 I try to add is within the /64 range configured in /etc/sysconfig/network-scripts/ifcfg-eth0, but that is how it should be, right?

Do I need to restart anything in between?

It will fail if the range that IPv6 address is part of is already configured to /etc/sysconfig/network-scripts/ifcfg-eth0.

Can I leave the shared ipv6 empty and just work with an enabled range and assign ipv6 to domains/accounts?

Yes, that should work, as there's no requirement to configure a shared IPv6 address.

Thank you.

 

[ZZPlab]

I'm getting further here, thanks. The basic concept of not overlapping IP's is now clear en solves the basis issue here.
Also DNS AAAA record was not set right for the IPv6/hostname. With that being fixed I can add the shared IPv6 in Basic WebHost Manager® Setup.

If do that automatically a range is added by cPanel with 2xxx:xxxx:xxxx:xxxx:1111::1/64 in IPv6 Address Ranges.
And I cannot change or delete that range to a /128 or anything else.
That way I cannot add my range 2xxx:xxxx:xxxx:xxxx:1111::/112 or any other portion of the /64 range.

If I first add a 2xxx:xxxx:xxxx:xxxx:1111::/128 range and then the shared 2xxx:xxxx:xxxx:xxxx:1111:: in WebHost Manager® Setup. That also works. But cPanel after that still adds the 2xxx:xxxx:xxxx:xxxx:1111::/64 range, blocking any other smaller ranges within the /64 I want to add. That way I cannot use shared and dedicated together.
What is the point cpanel add the range 2xxx:xxxx:xxxx:xxxx:1111::/64? That way only one IPv6 address is being used from the whole range.

I still also want the hostname to work with IPv6 too. How does that work? With or without the shared IPv6 set up?

 

[cPanelMichael]

I still also want the hostname to work with IPv6 too. How does that work? With or without the shared IPv6 set up?

It should work by default once you've setup the shared IPv6 address in "WHM >> Basic WebHost Manager Setup" and added the corresponding AAAA record for the hostname using "WHM >> Edit DNS Zone". Is it not working on your system?

What is the point cpanel add the range 2xxx:xxxx:xxxx:xxxx:1111::/64? That way only one IPv6 address is being used from the whole range.

This is discussed on the following feature request:

IPv6 Address Pooling (non-contiguous IP ranges)

I encourage you to vote and add feedback to this request if it's something you'd like to see implemented.

Thank you.

 

[ZZPlab]

All together I got it solved and working fine now.
Thanks Michael for the help and directing to the right track for finding the solution.
Shared ipv6 and ipv6 ranges are not overlapping anymore.

Having to add multiple ranges (part of the /112) in order to use the whole /112 is not handy... I will vote the discussion for a better solution.