I am running OpenWrt 22.03.5 r20134-5f15225c1e(fresh install) on Raspberry Pi 4 Model B Rev 1.4 and trying to wrap my head around ipv6 connectivity.
My ISP gives me a /64 ipv6-pd. My clients who are capable of getting ipv6 address do receive it via DHCPv6. I have turned off SLAAC on my LAN interface and have "RA-Service" and DHCPv6-Service" in server mode.
Following are the settings for lan==>advanced settings
Use default gateway = off
Delegate IPv6 prefixes = off
IPv6 assignment length = 64
IPv6 assignment hint = 5
IPv6 suffix = ::1
No changes are made to the firewall traffic rules and everything is just the default values. The issue I am facing is that even though the clients receive the ipv6 address, I am not able to ping ant ipv6 address from the client machine or from the Openwrt router. When I try to ping ipv6 from client machine, I get a message stating "icmp_seq=35 Destination unreachable: No route". Same goes when I try to ping ipv6 from the router; the error message is "PING ipv6.google.com (2404:6800:4007:82b::200e): 56 data bytes
ping: sendto: Network unreachable".
My ISP provides he PPPoE connection via a LAN cable. When this cable is directly connected to my laptop. I get ipv6 and I am able to ping all ipv6 resources. However, as soon as this cable is connected to my Pi4 USB adaptor on eth1 interface, the ipv6 issue resurfaces. I have no issue with ipv4 routing though.
I have tried different builds and even snapshot version but all result in the same issue that I just described. I am quite new to this whole ipv6 world and I am not able to figure out what the issue is even after spending around 2 days and playing with every possible setting that I think could have impacted ipv6 connectivity.
Any help will be highly appreciated.
Thanks and have a nice day.
Edit: When I visit https://test-ipv6.com/ to test my ipv6, the online tool doesn't detect my ipv6 even though I see a valid IPv6 on the wan6 interface on my router labelled as "ipv6-pd".
I just restore back to my openvpn config. Now I am not using directly wan. It will take time to reset and do from start for me.
What you can do is go and reset your router from scratch. Set your everything. And when only ipv4 works, set those settings.
For prefix delegation to work, the WAN IP has to be in a different prefix than the LAN. The WAN IP could be a /64 in a separate prefix for each customer, or a /128 in a /64 that is shared with other customers. The delegated prefix is different, either a completely separate one or a prefix larger than /64 with the WAN using a /64 within that larger prefix.
If the ISP works this way (as recommended by standards), traffic returning to the router itself (e.g. a NTP exchange to set the internal clock, or a forwarded DNS request) uses the WAN prefix/IP, and in addition the ISP will route the delegated prefix from the Internet to your house so that your router can route it to a LAN.
If the ISP has your "delegated /64 prefix" be the same as the prefix they assign for your WAN interface, you don't actually have a delegated prefix, and you'll need to use relay assignment to put LAN devices in the same prefix as the WAN since this is the only prefix that the ISP can route to your house.
I matched your config and still cannot ping ipv6 from local machine and from the router.
On wan6 interface on the router I can see 2 address-
On lan interface I can see the following address-
IPv6: xxxx:xxxx:xx:xxxx::1/64 (this is same as my wan6 ipv6 address)
On my wan interface I can see my static IP and the following ipv6 address-
IPv6 is driving me nuts. I guess I have to just shut it off and forget abt it as I am just not able to get it to work with Openwrt. Surprisingly the direct cable from my ISP when hooked to my laptop gives an ip address and all test pass successfully and I am also able to ping all ipv6 sites/addresses.