While creating the server I didn’t add any IPv6 address. Later from the Control Panel I enabled IPv6 but the address didn’t get attached to ETH0. Needed to do: Edit the /etc/network/interfaces.d/50-cloud-init.cfg file Add # control-alias eth0 iface eth0 inet6 static address 2400:xxxx:xxxx:xxxx:xxxx:xxxx:0000:6001/64 gateway 2400:xxxx:xxxx:xx::x autoconf 0 dns-nameservers 2001:xxxx:xxxx::xxxx 2001:xxxx:xxxx::xxxx The gateway and nameservers are… Continue reading Adding IPv6 to existing server (DigitalOcean)