General • Re: Pihole and IPv6 - getting it to work

I don't mean to hijack this thread but I have the exact same issue except my ISP provides a /64 prefix that I announce to the LAN via bridge0.

How can I assign a GUA IPv6 from this prefix to Pihole running on veth1 attached to the docker bridge? Can this be achieved without ULA?
In my situation, this would make things easy to manage as default routes are already setup and only firewall rules would be needed.

You can try to put ::/56 into the "Prefix Hint" field of the DHCPv6 Client entry, maybe your ISP does provide something bigger than /64. That would be the ideal case.

If it doesn't work and they only provide you with a /64 then unfortunately you cannot use it with SLAAC on bridge0 while at the same time cherry pick some addresses under that prefix to be used with your containers. If you manually pick some addresses and then manually add some /96 or /128 destination route to your router route table, the devices on bridge0 won't use those routes, because to them, all addresses under the same /64 prefix are "on-link" and they'll do this https://en.wikipedia.org/wiki/Neighbor_ ... ol#Example when trying to connect to those addresses, bypassing the router. If you want to share the same /64 between bridge0 and the docker bridge, you'll have to abandon SLAAC, and assign/configure addresses and routes manually on each device.

With only a single available /64 GUA, the best solution is still to use ULA for your docker bridge. And for the hosts with ULA address to be able to connect to the internet, you'll need a NAT (masquerade) rule, like with IPv4. Something like


Of course, on the devices IPv4 will be prefered to the ULA addresses, due to https://datatracker.ietf.org/doc/html/r ... ection-2.1.

Statistics: Posted by CGGXANNX — Wed May 29, 2024 10:27 am

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