Network manager and split DNS for a VPN?

[Paul Smith]

On Wed, 2017-04-12 at 09:13 +0200, Xen wrote:
> Karl Auer schreef op 12-04-2017 1:03:
> 
> > It *should* work, and dnsmasq it even *looks* as if it is doing it, but
> > it isn't actually working. Here is a sample bit of dnsmasq log file
> > after the VPN comes up:
> 
> Question: can you query the dnsmasq contents while it is running?

I don't know of a way to query it.  But you can turn on logging; do
this:

  $ sudo -s

  # echo log-queries > /etc/NetworkManager/dnsmasq.d/log-queries

  # killall -HUP NetworkManager

Now every DNS lookup you make will have lots of information about
exactly how the lookup was done logged: to see it use for example:

  $ journalctl -t dnsmasq

Delete the log-queries file if you no longer need the debugging.

> I never really liked the fact that dnsmasq (as a local nameserver) is 
> used by default by NetworkManager, although I guess it moves the
> inflexibility (?) of /etc/resolv.conf to something more developed.

It is annoying that what used to be easily available is now hidden away,
I agree.  On the other hand the functionality it provides is important
if you need more advanced networking than wired systems with a single
static-ish interface, such as split tunneling, VPN, virtual networking
(for VMs etc.) and probably other reasons.