IPv6 Routing to Downstream Router

[sifrmoja]

For clarification; I previously used a Mikrotik Router with this configuration and everything worked perfectly.

I am having bizarre issues with routing IPv6 to downstream routers from my OPNsense router. It works to a point and then causes all sorts of problems. It seems almost random.

Here is a guide I wrote about how it was all configured with my Mikrotik setup.

I have a couple of servers downstream from my OPNsense that are running Incus for containers and VMs. I manually set a IPv6 /64 network on the Linux bridges on those servers. In OPNsense I have created a disabled gateway with the IP of the server and then a route to the IPv6 subnet assigned to the linux bridge.
This gives access to the servers but then I have all kinds of issues with delays and I'm unable to traceroute between containers/VMs on the servers. The containers on one server have no issues with accessing everything sometimes and then it starts to fail.

I was hoping someone might have instructions on how they have configured this type of setup and I might see where I have gone wrong.

[Monviech (Cedrik)]

Random access issues between clients sound like NDP (NA, NS) not working correctly. Do packet captures to see if all neighbors can find each other.