Link-local address on WAN with IPv6 on none

[UserTom]

Hi All,

I got 1 single /64 IPv6 subnet for our OPNsense router. The gateway is fe80::1 on the router itself.

After some testing with my IPv6 setup:
Assigned the IPv6 subnet (IPv6Address::1/64) to the LAN interface and a part of it in the DHCPv6 settings.
The WAN interface got a link-local address, but only when I activated one of the IPv6 options. I disabled IPv6 on the WAN interface and the link-local address exists until reboot. After the reboot it is gone.

How can I ensure that the link-local persists after reboot? It looks like this configuration works with the /64 subnet. Other tips and tricks are also welcome.

[Maurice]

Disabling IPv6 on an interface disables it completely, including the link-local address. That's by design. If DHCPv6 or SLAAC aren't available to you and you don't have a static WAN GUA either, simply set it to "Static IPv6" and enter a link-local address, e. g. fe80::a/64.

Cheers
Maurice

[UserTom]

Disabling IPv6 on an interface disables it completely, including the link-local address. That's by design. If DHCPv6 or SLAAC aren't available to you and you don't have a static WAN GUA either, simply set it to "Static IPv6" and enter a link-local address, e. g. fe80::a/64.

Cheers
Maurice

Perfect, I will assign fe80::a for now on the WAN interface. I indeed don't have SLAAC, DHCPv6 and GUA and limited to IPv6 /64 with fe80::1 as gateway in this case. I can use the whole /64 block without any issues now.