I've verified that networking.service does not take down 'lo' interface with the proposed version in yakkety (0.8.13ubuntu3).
Below, first I show the problem in 0.8.13ubuntu2 and then install the proposed version and show it fixed. $ lxc launch ubuntu-daily:yakkety y1 $ sleep 10 $ lxc exec y1 /bin/bash % dpkg-query --show ifupdown ifupdown 0.8.13ubuntu2 ## show only things that are up (note output has LOOPBACK,UP,LOWER_UP) % ip link show dev lo 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 % ip address show dev lo up 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever ## Stop the service and show lo link is down (no 'UP' or 'LOWER_UP'). % systemctl stop networking.service % ip link show dev lo 1: lo: <LOOPBACK> mtu 65536 qdisc noqueue state DOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 % out=$(ip address show dev lo up); [ -n "$out" ] && echo "$out" || echo empty empty ## Now enable proposed, install update, reboot and show. % rel=$(lsb_release -sc) % echo "deb http://archive.ubuntu.com/ubuntu $rel-proposed main" | sudo tee /etc/apt/sources.list.d/proposed.list % sudo apt update -qy && sudo apt install -qy ifupdown </dev/null % dpkg-query --show ifupdown ifupdown 0.8.13ubuntu3 % sudo reboot ## in rebooted system % ip link show dev lo 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 % ip address show dev lo up 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever % systemctl stop networking.service % ip link show dev lo 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 % out=$(ip address show dev lo up); [ -n "$out" ] && echo "$out" || echo empty 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever ** Tags removed: verification-needed ** Tags added: verification-done -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1629972 Title: networking stop incorrectly disconnects from (network) root filesystem To manage notifications about this bug go to: https://bugs.launchpad.net/maas/+bug/1629972/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs