Systemd Networkd

IPV6 EUI64 Address Generation

This will ensure a static IPV6 Address that is based on your mac address.

You can tell if your ipv6 is eui64 if it has an fe:ff in between the 6th and 7th number.

NetworkManager

(Fedora Server, Raspberry Pi, Debian)

nmcli connection show --active
nmcli -f ipv6.addr-gen-mode connection show <connection>
nmcli con mod <connection> ipv6.addr-gen-mode eui64
systemctl restart NetworkManager
nmcli -f ipv6.addr-gen-mode connection show <connection>