[SOLVED] WAN has no IPv6 connectivity, ISP only provides /56 prefix

[andicniko]

My WAN doesn't seem able to reach IPv6 addresses (e.g. if I "ping -6 2606:4700:4700::1111" from opnsense itself).

• I wonder if this is the root cause of update checks going painfully slowly unless I enable System: Settings: General: Prefer to use IPv4 even if IPv6 is available.
• I also wonder if this is the root cause of IPv6 connectivity tests (e.g. https://test-ipv6.com/) suggesting "Your DNS server (possibly run by your ISP) appears to have no access to the IPv6 Internet". I can get around this by adding DNS over TLS entries in Unbound pointing to an external DNS, but it didn't help the above issues.

My configuration type is DHCP and DHCPv6, and my ISP provides me with a static /56 prefix. Clients on LAN get IPv6 addresses and communicate just fine, they can reach IPv6 addresses and "ping -6 2606:4700:4700::1111" getting a response just fine.

My interfaces overview suggests WAN has the following IPv6 addresses only:
::2e0:97ff:fe1d:8a79/64
fe80::2e0:97ff:fe1d:8a79/64

Question: How can I give my WAN interface a usable IPv6 address, or get the one's it already has to communicate with external IPv6 addresses?

Sorry I know this has been asked in the past, but I can't seem to find a clear answer. Any help is appreciated!

[meyergru]

Try this.

[andicniko]

Confirming that specifying an "Optional prefix ID" fixed my issues.

That's a very useful explanation you linked to as well. Thank you.