IPv6 help to downstream router

Hi all, is there a way to pass all IPv6 traffic to a downstream router. I get one /64 from my ISP and OpenWRt is using it. I need it to be passed to a downstream router and OpenWrt to not use it.

It should be possible.
On lan interface set ip6class to local. Then add a static v6 route for the delegated prefix to the downstream router using gateway the ULA or Link Local address.

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Thank you for helping me!
Sorry for my ignorance on this but I mainly do everything through luci, is there a way to set these this way?

I know you probably won't get this resolved through your ISP but this is a broken config and make sure you complain to your ISP, if people don't complain then ISPs will continue this broken practice and the internet will continue to be broken like it has been since the 1990s when NAT became standard!

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Oh yeah, I've been on the phone with them. Long story short is they won't fix it and would not give a reason other than it is more expensive for them to give out more than a /64. Which doesn't make any sense to me.

That's a bullshit excuse. Ask them how Comcast can possibly be handing out /56 if its so expensive :wink:

No, add it from ssh.
uci set network.lan.ip6class=local ; uci commit network; ifup lan

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Thank you so much!! I would like to test this. If things go wrong what command would I issue to return everything to what is was previously?

uci delete network.lan.ip6class; uci commit network; ifup lan

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Thank you so much! Trying now :slight_smile:

So I believe that is working, my downstream router will get a IPv6 address still but the address do not have internet access

How would I set this up from my wan1?


So would it be:

config route6
        option interface 'lan'
        option target 'xxxx:xxxx:xxxx:xxxx::1/64'

How does it know to get the IPv6 from wan1, do I need to define that?

You are missing the gateway option that should be the downstream router ULA address.

It should be routable via the respective interface, see:

ifstatus wan1

In addition we are assuming that your prefix is static.
Otherwise, you need to manage the route dynamically:

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It is definitely not a static prefix

I have everything configured with the gateway now just to see if it would work. But in the system log I am getting "DHCPV6 REQUEST IA_PD from xxxxxxxxxxxxxxxxxxxxxxx on br-lan: no prefix available.

I am assuming OpenWrt is still taking my one prefix.

Is there a way for a full bridge of wan1 and lan? wan1 is a lte modem.

I see the OpenWrt wiki page talks about different bridge modes. Full bridge and LTE/5G Half Bridge sounds like it would work for me. Is this supported?

It is just real odd, my openwrt device will hand out as many IPv6 address as I need no problem but when I hook up the downstream router no matter what I try, dhcpv6, dhcpv6-pd and relay mode all fail to give access to the internet from that router.

My ISP supplies the one /64 prefix and gives me a IPv4 address through ds-lite

That complicates things.

Sure there is, but then you could take out the OpenWrt altogether.

You should configure the downstream router to relay RAs and DHCP6, as well as proxy NDP.

As mentioned earlier, this is a rubbish setup from your provider causing all those issues. My local provider in a village of 3000 inhabitants in Central Europe delegates a /56.

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Is there anything else I need to do? If I use relay my downstream does not pick up an address

I have to have the OpenWrt for its modem interface. Full bridge mode is something to try just to see if that works. I'd much rather use relay.

I am out of ideas, sorry.

Thank you so much for helping me! Has definitely given me a couple ideas.

Maybe I could pass a vlan from the openwrt to the downstream and let the openwrt handle the dhcp for IPv6