My ISP recently made IPv6 available and I’m trying to figure out how to make it work with my network. The setup I have is an OPNsense box connected to my ISP’s router and I’m using it to isolate my homelab from the rest of the network. However, the machines on my OPNsense LAN aren’t being assigned IPv6 addresses that allow them to connect to the internet.
I can ping IPv6 sites from my OPNsense box and I see that it’s being assigned a /64 prefix from the ISP router. If I use my laptop to connect to my ISP’s router, I can visit IPv6 sites just fine as well. My devices in the OPNsense LAN also have IPv6 addresses and can ping each other using IPv6 but not the internet.
Are there special settings that I need to set for OPNsense to make this setup work? I’ve tried reading up on the different modes like SLAAC but I’m not quite grasping the concepts.
Confirm the ipv6 addresses your clients in the LAN are being assigned an ipv6 address within the scope of what your ISP is assigning.
If you are check default routes and firewall rules.
If you aren’t, investigate “router advertisement”.
I did forget to mention that. The IP addresses of the devices on the LAN do not share the same first half of the address as the IP on the ISP router. I have the OPNsense LAN set to track WAN interface, but the DHCP server is stuck saying “No available address range for configured interface subnet size.”. I also noticed that my WAN for OPNsense has a global routable IP starting with 2402 as well as a LLA starting with fe80 but my LAN only has a LLA.
Which routes and firewall rules should I be checking?
If your lan devices only have a fe80, your clients are not receiving a proper router advertisement.
Since the OPNsense device is getting a ipv6 address and is able to ping ipv6 devices on the internet.
It sounds like you don’t have ipv6 configured for the LAN. Try enabling “Assisted” mode.
https://docs.opnsense.org/manual/radvd.html