Refer to the ip-token(8) man page for what this is, but also the referenced URL. There are already existing hacks as per the referenced URL, I just think this can be better formulated such that this can get configured in /etc/conf.d/net using lines like: ip6token_eth0="::dead:beef" ip6token_eth0="::192.168.0.1" ip6token_eth0="::1" For example. And this is what I've done, just want to action a bit more testing before filing a PR. I'm not going to implement the fe80:: hack to also assume the token address for Link-Local (LL), if this is desired I'll look at it, but for now LL addresses can stay EUI64 addresses, as a rule nobody should be looking at these anyway. Reproducible: Always