dnsmasq doesn't manage destruction/recreation of tun interface

[Paul Smith]

This issue happens in Ubuntu 16.04 LTS as well.

When I connect via tun to an OpenVPN server, my DNS lookups do not succeed even though the OpenVPN service is started correctly and does provide the correct information. If I force NetworkManager to load its configuration via "killall -HUP NetworkManager" then it works.

  $ host git.my.domain.com
  Host git.my.domain.com not found: 5(REFUSED)

  $ sudo killall -HUP NetworkManager

  $ host git
  git.my.domain.com has address 192.168.1.7

Looking around I see that this appears to be an instance of this bug, in dnsmasq:

https://bugzilla.redhat.com/show_bug.cgi?id=1367772

There are TWO patches (already applied to the dnsmasq source and queued for the next release, which is not out yet) needed to fix this problem, both mentioned in the above bug:

http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commitdiff;h=2675f2061525bc954be14988d64384b74aa7bf8b
http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commitdiff;h=16800ea072dd0cdf14d951c4bb8d2808b3dfe53d

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: dnsmasq-base 2.76-4
ProcVersionSignature: Ubuntu 4.8.0-41.44-generic 4.8.17
Uname: Linux 4.8.0-41-generic x86_64
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: GNOME
Date: Mon Mar 27 16:00:03 2017
InstallationDate: Installed on 2014-04-28 (1064 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
SourcePackage: dnsmasq
UpgradeStatus: Upgraded to yakkety on 2017-03-25 (1 days ago)

[Robie Basak (racb)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

We think this is the same issue as tracked in bug 1639776, so I'll mark this as a duplicate.