kazulog@sv1:~$ sudo cp /tmp/60-ens3-v6.yaml /etc/netplan/60-ens3.yaml && sudo chmod 600 /etc/netplan/60-ens3.yaml
kazulog@sv1:~$ sudo netplan apply
kazulog@sv1:~$ ip -6 a show ens3
3: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    altname enp0s3
    altname enx525400ba7498
    inet6 2001:db8:100::10/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:feba:7498/64 scope link proto kernel_ll 
       valid_lft forever preferred_lft forever
kazulog@sv1:~$ ip -6 route show dev ens3
2001:db8:100::/64 proto kernel metric 256 pref medium
fe80::/64 proto kernel metric 256 pref medium
default via 2001:db8:100::1 proto static metric 200 pref medium
kazulog@sv1:~$ ping6 -c 3 2001:db8:100::1
PING 2001:db8:100::1 (2001:db8:100::1) 56 data bytes
64 bytes from 2001:db8:100::1: icmp_seq=1 ttl=64 time=21.6 ms
64 bytes from 2001:db8:100::1: icmp_seq=2 ttl=64 time=3.29 ms
64 bytes from 2001:db8:100::1: icmp_seq=3 ttl=64 time=2.23 ms

--- 2001:db8:100::1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2005ms
rtt min/avg/max/mdev = 2.226/9.040/21.606/8.895 ms
kazulog@sv1:~$ ping6 -c 2 2001:db8:100::20
PING 2001:db8:100::20 (2001:db8:100::20) 56 data bytes
64 bytes from 2001:db8:100::20: icmp_seq=1 ttl=64 time=3.53 ms
64 bytes from 2001:db8:100::20: icmp_seq=2 ttl=64 time=1.57 ms

--- 2001:db8:100::20 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 1.573/2.553/3.534/0.980 ms