Machine fails to stop, or start interfaces. hangs in systemd waiting for completion

[LaMont Jones]

The attached /etc/network/interfaces file is fatal to /lib/systemd/system/networking.service, resulting in a loop that never finishes.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: ifupdown 0.8.13ubuntu4
ProcVersionSignature: Ubuntu 4.4.0-14.30~lp1543683LatestXenialWithRevert-generic 4.4.5
Uname: Linux 4.4.0-14-generic x86_64
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Oct 21 09:14:33 2016
InstallationDate: Installed on 2014-09-22 (759 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
SourcePackage: ifupdown
UpgradeStatus: Upgraded to zesty on 2014-11-14 (706 days ago)

[LaMont Jones (lamont)]

After you change your /e/n/i to that, and reproduce the issue, break=init, and then mount -oremount,rw /root; chroot /root; vi /etc/network/interfaces and comment out everything from "auto br1" to end of file, exit; mount -oremount,ro /root; exit

and you're back to a bootable system... Which is why the apport files are pretty much useless on this report.

[LaMont Jones (lamont)]

The reboot of the system prior to this morning was after a dist-upgrade on "2016-10-14 08:30:10" according to /var/log/apt/history.log -- the upgrade to zesty occurred on 2016-10-18, and the reboot was after a fresh dist-upgrade this morning, on zesty.

[dino99 (9d9)]

Looks like a local issue, or a temporary one as no-one else have hit it. And zesty is now off.