root@lp1859862-b:~# dpkg -l systemd|grep ii
ii systemd 237-3ubuntu10.39 amd64 system and service manager
root@lp1859862-b:~# cat /proc/sys/net/ipv6/conf/ens3/disable_ipv6
1
root@lp1859862-b:~# ip -6 a show dev ens3
root@lp1859862-b:~# systemctl restart systemd-networkd
root@lp1859862-b:~# ip -6 a show dev ens3
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
inet6 2001:db8::100/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::5054:ff:fe0c:977/64 scope link
valid_lft forever preferred_lft forever
root@lp1859862-b:~# cat /proc/sys/net/ipv6/conf/ens3/disable_ipv6
0
bionic verification:
root@lp1859862-b:~# dpkg -l systemd|grep ii net/ipv6/ conf/ens3/ disable_ ipv6 MULTICAST, UP,LOWER_ UP> mtu 1500 state UP qlen 1000 ff:fe0c: 977/64 scope link net/ipv6/ conf/ens3/ disable_ ipv6
ii systemd 237-3ubuntu10.39 amd64 system and service manager
root@lp1859862-b:~# cat /proc/sys/
1
root@lp1859862-b:~# ip -6 a show dev ens3
root@lp1859862-b:~# systemctl restart systemd-networkd
root@lp1859862-b:~# ip -6 a show dev ens3
2: ens3: <BROADCAST,
inet6 2001:db8::100/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::5054:
valid_lft forever preferred_lft forever
root@lp1859862-b:~# cat /proc/sys/
0