Network manager and split DNS for a VPN?

[Paul Smith]

On Wed, 2017-04-12 at 09:03 +1000, Karl Auer wrote:
> On Tue, 2017-04-11 at 18:46 -0400, Peter Silva wrote:
> > fwiw, every time I startup a vpn connection, dns breaks, it won't
> > answer any queries, so I kill dnsmasq.  Something starts it back up,
> > and it's OK (resolves the internal addresses as per the vpn
> > connection.)   It started a month or two ago...
> 
> Thanks.
> 
> I can resolve stuff over the VPN if I disable dnsmasq and restart NM. I
> can resolve local addresses as long as either dnsmasq is running OR the
> VPN is not up. As soon as the VPN comes up without dnsmasq, the
> nameservers acquired over the VPN are first in /etc/resolv.conf, and my
> local nameservers are never queried.

I'm fairly sure you're all experiencing this bug:

https://bugs.launchpad.net/bugs/1639776

There is a fix (to dnsmasq-base) already in -proposed for both Xenial
and Yakkety.  I'm waiting and hoping for this fix to get promoted to
-updates soon; it's been verified for almost 2 weeks now (but, it's a
busy time).

You can run "sudo killall -HUP NetworkManager" to fix it; you can add a
script to force that to happen every time you bring up a VPN interface,
or you can get this package from -proposed.

Cheers!