IPv6 ULA routing through WAN

Installing and Using OpenWrt
1

Hey, I have the following network situation:

network
network776×425 11 KB

The OpenWRT router is configured through LuCI, never used other configuration options than the WebUI.

  • Global network options fd00:1:2::/48 is set as ULA prefix
  • WAN is set to DHCP client
  • WAN6 is set to DHCPv6 client
  • LAN side is set to
    • static IPv4: 10.1.0.1/24
    • IPv4 gateway: 10.0.2.1
    • IPv6 assignment length: 64
    • IPv6 assignment hint: a

From the OpenWRT Router I can ping client 1 and client 2

  • :white_check_mark: from the WAN IPv4
  • :white_check_mark: from the WAN IPv6
  • :white_check_mark: from the LAN IPv4
  • :x: from the LAN IPv6

From the client 3 I can ping client 1 and client 2

  • :white_check_mark: by IPv4
  • :x: by IPv6

Traceroute from client 3:
IPv4:

1  _gateway (10.1.0.1)  0.450 ms  0.519 ms  0.570 ms
2  _gateway (10.0.2.1)  1.928 ms  1.895 ms  1.861 ms
3  client1 (10.0.1.100)  2.344 ms  2.316 ms  2.287 ms

IPv6:

1  fd00:1:2:a::1 (fd00:1:2:a::1)  0.547 ms !N  0.622 ms !N  0.745 ms !N

Traceroute from OpenWRT WAN address:
IPv6:

1  OPNSense (fd00:a:b:2::1)  0.494 ms  0.449 ms  0.405 ms
2  client1 (fd00:a:b:1::100)  0.710 ms  0.703 ms  0.645 ms

So, the OpenWRT router definitely knows the route to fd00:a:b::/48, as it's possible to speak to client 1 from the OpenWRT's wan address.
The client 3 tries to go through the OpenWRT router, so the default gateway was propagated correctly.
It always stops when it comes to routing on the OpenwRT router from the Lan to the WAN Gateway on IPv6.
What setting am I missing here? :face_with_monocle:
Has that todo with the fact that those are all ULA prefixes and OpenWRT doesn't route them out the WAN interface by default?

2

Add an IPv6 static route on OPNSense to fd00:1:2:a::/64 via the WAN IPv6 of OpenWrt.

1 Like
3

I couldn't reach clients in the 10.1.0.0/24 or fd00:1:2:a::/64 from the OPNSense side. But the other way around I could reach the 10.0.1.0/24 from the OpenWRT Lan.

Adding a static routes for the OpenWRT Lan networks to the OPNSense did in fact enable the communication from OPNSense side to the OpenWRT Lan with v4. But I can't get through with v6 :person_shrugging:t3:

But as this isn't the actual setup I want to make, but just a quick playaround, I won't invest too much energy solving this now.
Thanks so far. If I get the chance to setup a proper test environment I'll maybe push this again if I get problems there as well :v:t3: