In reply to a post by Andrue:

The FEED address can be used by the router to configure itself with an IPv6 address, the routed block is then meant to be delegated by the router to end clients. Other routers will just take the 1st address from the routed /48 instead.

The routed block refers to the /48 (not FEED) from which the router is supposed to assign to LAN hosts.

What the second sentence above means that it is a valid option for the router itself to only use a link-local on the WAN interface to configure as the default route to Internet and then choose an address from the routed /48 as its own primary management GUA IP.
By design this can still work for connecting to the router UI from both internal and external connections though it depends on the specifics of the firewall policy.

The reply is not saying it is meant for LAN clients to end up alongside the router on the WAN interface IP subnet.

For work we have multiple sites on IDNet circuits and I manage the configuration for our routers.
We have circuits from various ISPs (including some Starlink) so there's some static assignment and some using SLAAC and/or DHCPv6-PD in the mix and even some scenarios where our v4 option is only CGNAT.

As per sig though I have vanilla FTTC Zen at home it works the same way with regards to the /64 WAN and then routed /48 for LAN.

Edited by prlzx (Thu 24-Oct-24 01:36:09)

It it is what it looks like, it's quite a neat way of having some self documenting addresses; the /64 point-to-point WAN subnet is documented as "feeding" the /48 delegation

For what it's worth I wound back the firmware update and the router immediately started issuing addresses on the ::1 subnet and routing to my server was working again. Draytek support responded to that stating that as it was a bug introduced by a security update a fix would be released (after previously noting that as the router is End of Life no fixes would be released).

I suppose it remains to be seen whether such a fix will appear. There are 'no known issues' with the current firmware according to the readme so I'm sceptical. I will be considering replacing my router when FTTP arrives here (some time this year I suspect from the recent Openreach activity around town). To be fair Draytek support was better than I expected in that they at least engaged with me but at the end of the day engagement is only a good start. It's not the same as fixing a fault.

If I can ask a side Q here as it relates to IPv6...

I am in CH and Swisscom have enable IPv6 on my router by default, but as I will never have more devices than IPv4 can cope with... Is there ANY advantage in using IPv6 on a home network... in my reading I can only see problems... that and I can relatively easily remember an IPv4 address, but haven't a cat-in-hell's chance of remembering an IPv6 one.

A

In reply to a post by nonymouse:

Is there ANY advantage in using IPv6 on a home network... in my reading I can only see problems... that and I can relatively easily remember an IPv4 address, but haven't a cat-in-hell's chance of remembering an IPv6 one.

Let's think about address memorisation first: you should have a reliable DNS setup which means you very rarely need to type, let alone remember, an IP address. If your DNS isn't reliable then I'd suggest fixing that.

IPv6 gives you the option (assuming your firewall allows it) of end to end connections between the devices on your network and other devices on the internet, including devices on networks where there are inadequate IPv4 addresses. It's possible that your ISP has given you a generous allocation of IPv4 addresses, but it's likely that you're using NAT to share a single address, in which case enabling IPv6 will reduce the amount of work that your router needs to do for NAT. The same is true of the other side -- you might be able to bypass congested paths involving shared IPv4 addresses in favour of a direct path over IPv6.