How do I get the default Network Manager plus dnsmasq-base setup back again?

[Chris Green]

On Sat, Jan 05, 2013 at 05:33:34PM +0200, Marius Gedminas wrote:
> On Sat, Jan 05, 2013 at 02:28:01PM +0000, Chris Green wrote:
> > A while ago I installed the 'full' dnsmasq package on my desktop machine
> > so that it ran as a the DNS and DHCP server on my LAN.  In addition to
> > installing dnsmasq (and configuring /etc/dnsmasq.conf) I commented out
> > the dns=dnsmasq line in /etc/NetworkManager/NetworkManager.conf.
> > 
> > This setup worked fine for a while but now I want to use another server
> > on my LAN to provide DNS and DHCP.
> > 
> > I have removed the dnsmasq package from my desktop machine and have
> > uncommented the dns=dnsmasq line in /etc/NetworkManager/NetworkManager.conf.
> > However Network Manager *isn't* running dnsmasq as it should.
> > 
> > How do I get back to the default setup with dnsmasq being run by Network
> > manager as a caching DNS server?  I have tried uninstalling and
> > reinstalling Network Manager but that doesn't help at all.
> > 
> > What do I have to do?
> 
> IIRC you have to apt-get purge dnsmasq.
> 
I've done that, still no dnsmasq running with network manager.

> Elaboration: dnsmasq is a tiny package that depends on dnsmasq-base
> (which has the dnsmasq server) and installs /etc/init.d/dnsmasq (which
> runs the global dnsmasq server).  Now /etc/init.d/dnsmasq is a conffile,
> like all files in /etc.  When you remove a package, its conffiles are
> left in place -- which means removing the dnsmasq will still keep the
> startup script so the global dnsmasq will continue to run.
> When you purge a package, its conffiles are removed as well.
> 
> This is a bug in the dnsmasq package, and I'm ashamed to say I haven't
> found the time to report it.
> 
I have another system which has the default (i.e. original) Network
Manager and dnsmasq setup and there everything works fine.  I have
compared everything I can think of and can see no significant
differences.

In /var/log/syslog on the non-working system there is the line:-

    Jan  5 13:32:10 acer-aspire NetworkManager[778]: <info> DNS: loaded plugin dnsmasq

and then *nothing* about dnsmasq at all, no errors or anything.  On the
working system the above message is followed by lots of further
information about dnsmasq.

It certainly *used* to work on this system but I just can't get back to
the original setup.

-- 
Chris Green