Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.

ravenstar68 — Tue, 20 Oct 2026 05:07:23 GMT

I am attempting a rather unique home setup where I have a device on my home network act as IPv6 router and then pushes packets to the BT hub LAN Link Local IPv6 address and they go on to the internet from there.

To achieve this I have a Linux box set up with ISC running DHCPv4 Bind running DNS and RADV and RDNSS set up sending RA's advertising the /64. Once this was running I set the BT Hubs IPv6 address allocation to none. My understanding is that you cannot have 2 devices on the same network sending out RA's

This worked for an hour or 2 then after a while I lost IPv6 connectivity.

Going back to the Hub I noted that the LAN side GUA was ::

Previously it was a GUA in the hubs /64 with the same host part address as the link local

i.e.

Link Local: fe80::c6e5:32ff:fe36:4d36/64

GUA: 2a00:xxxx:xxxx:xxxx:c6e5:32ff:fe36:4d36/64

This meant that packets lo longer had a clear IPv6 path to and from the internet AFAICT.

Turning Allocation to stateless and back to none restored the LAN side address until the address lifetime presumably given by the BT hub expires and then returns back to ::

My question is - is this by design?

I understand the possibility of the /56 and consequently the /64 changing down the line however should that happen my network will still retain IPv4 capability. However conceptually what I had set up WAS working until the hubs IPv6 LAN address vanished.

I would have hoped that the LAN side would have picked up the RA's from my linux box and configured the LAN IP using the advertised /64 or at the very least have an autoconfigured static address.

Thoughts would be welcomed here.

Thanks in advance.

Re: Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.

Edinburgh-wg — Tue, 20 Oct 2026 06:34:21 GMT

If your hub establishes an internet connection, I'm unclear why you switched off ipv6 on it. How is your Linux box to handle ipv6 queries - except on lan - if there is no ipv6 address?

Re: Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.

WSH — Tue, 20 Oct 2026 08:31:24 GMT

If the BT hub is sat between your Linux box and BT, how is the Linux box to get a global prefix from BT? If it is disabled, the BT hub won’t generate its own RA, and it can’t pass on any it gets from BT.

Perhaps I’ve misunderstood what you are trying to do.

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Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.

Re: Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.

Re: Home Hub - No LAN IPv6 Address when IPv6 Allocation set to none.