root@dc2:/home/eida# cat /etc/network/interfaces

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

# IPv4
allow-hotplug ens3
iface ens3 inet static
	address 10.5.5.102/24
	gateway 10.5.5.1
	dns-nameservers 10.5.5.100
	dns-search eida.lan

# IPv6
iface ens3 inet6 static
	address 2001:ab:cd:df::dc2
	netmask 64
	gateway 2001:ab:cd:df::1
	dns-nameservers 2001:ab:cd:df::a
	up /sbin/ip -6 route add default via 2001:ab:cd:df::1 dev ens3 onlink || true

root@dc2:/home/eida# cat /etc/resolv.conf
domain eida.lan
search eida.lan
nameserver 10.5.5.100
nameserver 2001:ab:cd:ef::a