Local Only IPv6 network

[Senjuu]

I want to create a "local only" network which can ONLY be accessed inside my local network. But I am currently struggling to setup IPv6 for it. As the devices in this network should not access the internet the do not need Global Unicast Address but I want to give them Unique Local Adresses.

Going to the interface settings I tried to select the right IPv6 configuration type. But they all seem not to be the right:
 - None -> I do want to setup IPv6
 - DHCPv6 -> on this network there is no DHCPv6 server OPNsense shall be it
 - 6rd/6to4 Tunnel -> I do not want to tunnel IPv6
 - Track Interface -> I do not want to track another interface as this network shall not get any GUA
 - SLAAC -> This only gives Link Local Unicast addresses

So what am I missing or is this feature not supported?

[Maurice]

Set it to 'Static IPv6' and enter a ULA, prefix length 64. You can then configure the DHCPv6 server and Router Advertisements in the 'Services' section. You might want to disable 'Advertise Default Gateway' in the RA settings.

Cheers

Maurice