I don't remember my ipv4 addresses either, but I recognize them as mine when I see them.
I've never recognized an IPv6 address or prefix used in my networks.
I've never recognized an IPv6 address or prefix used in my networks.
If you want to be really wonky you can script DHCPv6 to statically assign ULA IPv6 leases that match the IPv4, and expire them when the IPv4 lease expires, but like said upthread, addressing hosts via IPv6 is the wrong way to go about it. On your lan, you really want to be doing ".local" / ".lan" / ".home".
.local is fine as long as all the daemons work correctly, but AFAIK there's no way to have SLAAC and put hosts in "normal" internal DNS, so .lan/.home/.internal are probably out.
The "official" is home.arpa according to RFC 8375 [1]:
Users and devices within a home network (hereafter referred to as
"homenet") require devices and services to be identified by names
that are unique within the boundaries of the homenet [RFC7368]. The
naming mechanism needs to function without configuration from the
user. While it may be possible for a name to be delegated by an ISP,
homenets must also function in the absence of such a delegation.
This document reserves the name 'home.arpa.' to serve as the default
name for this purpose, with a scope limited to each individual
homenet.
".home" and ".lan" along with a bunch of other historic tlds are on the reserved list and cannot be registered.
Call techy people pathologically lazy but no one is going to switch to typing ".home.arpa" or ".internal". They should have stuck with the original proposal of making ".home" official, instead of sticking ".arpa" behind it. That immediately doomed the RFC.
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.