[dxld]

You can use ip-token(8) on Linux to define a static interface-id, the part of the IP usually auto-generated based on MAC address when using SLAAC instead of making the whole IP static.

In ifupdown I usually just add something like the following

    pre-up ip token set ::cafe dev $IFACE

This way when you get a new GUA there's no need to "renumber" your network manually as everything will just happen automatically. When your router includes a new prefix in the router advertisement all hosts on the LAN generate new addresses for this prefix.

Couple of gotchas. 1) The ip-token call has to happen before the interface is marked up (as in ip link set dev $IFACE up, not link presence) so if you want to change it you have to take it down first. 2) If your ISP's router doesn't cleanly announce the old prefix to be deprecated (due to a reboot say) it may remain in use by hosts until it's lifetime expires. See RFC4192 for how renumbering is supposed to work.

FYI: I'm working on a small daemon that will monitor RA and deprecated the prefix to handle broken ISP routers.

--Daniel

[Macha]

This is only a half solution, I'd still need to update all my dns entries and firewall rules, for example

[dxld]

Well dnsmasq has --dynamic-host for this use-case. Example:

    dynamic-host=cafe.dxld.at,::cafe,lan0

Firewalls tend to support DNS, use it :)

I know for a fact nftables and pfSense allow this, worst case you need a cronjob to periodically reload your ruleset to refresh the DNS data as it's evaluated at ruleset load time (for nftables). Incidentally another TODO project of mine is a daemon to allow running scripts when RA information (such as the prefix) changes, this would come in handy here too.

For anyone interested in making IPv6 bettter come talk to me in #ipv6:ungleich.ch (Matrix).

--Daniel

[Macha]

> Firewalls tend to support DNS, use it :)

So I did check and my firewall (the one built into my Unifi UDM), doesn't.

[dxld]

Sad to say I'm surprised the proprietary vendors are lagging behind here, but there should be no architectural reason you can't deploy a more reasonable firewall.