Setting up ipv6 *struggling*


I'm running 21.03.3 on a r7800, reset to the factory default config (with the exception of Wifi enabled).

My WAN connection is provided by a Huawei CPE Pro 2 5G router connected by ethernet to the r7800's WAN port. The Huawei is setup in bridge mode, looks to be passing the external ip/dns etc. to the r7800 for ipv4 and ipv4 works fine.

I'm struggling to get ipv6 working though.

So the r7800 reports the following for the IPv6 upstream connection. I'm getting a /64 address assigned and local-link addresses for the Gateway and DNS servers.


Of all my wireless clients, only one of the Windows 10 laptops shows as having a DHCPv6 lease. All other clients are assigned DHCPv4 leases.


I can't ipv6 ping / traceroute from the router (get network unreachable). I also can't ipv6 ping from the Windows laptop.

I'm looking to get dual stack ipv4/v6 working if possible. Where do I start with identifying whether the cause of the problem is the ipv6 WAN connection provided by Three or my config?

Sorry this is a post on such basics.

The IPv6 address you have is not a public IP.

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FC00::/8 and FD00::/8 are local address ranges for IPv6. Your fd14:7740:/64 address falls into the second range.

The IPv6 wiki instructions might be of help but first you'll need to check whether your ISP offers IPv6 at all, otherwise this is a fool's errand.


looks like your ISP sucks regarding IPv6 prefix delegation.

There is one alternative: search the forum, wiki or google for „ipv6 relay“

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Connect the PC directly to the modem and see if you can get a public (GUA) IPv6. These addresses start with 2 or 3.

LTE almost always restricts customers to a single /64, which means your router would need to use relay to assign LAN IPs within that same /64. But it has to be a GUA first.


So I connected directly to the 5G modem/router to eliminate any effect of the r7800. I can see the IPv6 address assigned to my laptop is still non-public so it's an ISP issue.

My ISP is (I'm using a phone sim) so I'm going to ask around and see if I have any options.

Thanks to everyone for your replies and your time:)

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