[somat]

I do it by abusing the static slaac address. I have a set of wierd vms where they are cloned from a reference image, so no fixed config allowed. I should have probably just have used dhcp6 but I started by trying slaac and the static address were stable enough for my purposes so it stuck.

[yjftsjthsd-h]

How does that work? I initially assumed you meant you just statically assigned machines to addresses, which I think would work courtesy of collision avoidance (and the massive address space), but I can't see how that would work for VMs. Are you just letting VMs pick an IP at random and then having them never change it, at which point you manually add them to DNS?

[somat]

Pretty much. A given mac address assigned in the vm config maps directly to a static slaac address(the ones they recommend you not use) and those preknown slaac address are in dns, Like I said, I should probably use dhcp6 but it was a personal experiment in cloning a vm for a sandbox execution environment. and those slacc address were stable enough for that. every time it gets cloned to the same mac address it ended up with the same ip6 address. works for me, don't have to faf around with dhcp6, put it in dns. time for a drink.

But the point is that is the address you would put in dns if you also wanted to use slaac. Most of the time however you will just set a manual address. And this was with obsd, where when slaac is setup you get the slaac address and a temporary address. I don't really know what linux does. Might have to try now.

[jorvi]

Clarification for others: with privacy extensions disabled, SLAAC'd IPv6 addresses are deterministically generated based on MAC addresses. There's also an inbetween (IPv6 are stable per network by hashing).