Re: Multiple VPNs and resolvconf

[Mathieu Trudel-Lapierre <mathieu tl gmail com>]

On Mon, Aug 10, 2009 at 8:44 AM, Graham Lyon<graham lyon gmail com> wrote:
> What about some method of checking which domains the dns on the end of the
> VPN is authorative for and only looking up that domain on that dns? Excuse
> my ignorance of dns if this is not possible...
>
> 2009/8/10 Marc Luethi <netztier bluewin ch>
>>
>> On Mon, 2009-08-10 at 11:51 +0200, Dominik George wrote:
>> > I'm not quite sure whether this is a problem. If nameserver A cannot
>> > resolve a hostname, the system will try nameserver B automagically, then
>> > nameserver C until it gets a result.
>>
>>
>> Not if the first nameserver returns NXDOMAIN; the local resolver will
>> accept this as a valid response and won't query another nameserver.
>>

I deal with this kind of problem and moving from wireless outside the
office with my own DNS, or wired in the office with their DNS, and on
top of that connecting to a VPN in either location with yet a
different DNS by using dnsmasq.

For each "special" domain that you want dnsmasq to query a very
specific nameserver for, add a server=/domain/nameserver_ip line.

The same could be achieved using just about any other kind of local
caching DNS server.

That said, it seems to me like a pretty good feature given that I also
use dnsmasq for virtual machines. The only thing that stays in
/etc/resolv.conf is "nameserver 127.0.0.1" and any "search" or
"domain" lines I may have.

Note that I had to point dnsmasq to check resolvconf's copy of the
resolv.conf file networkmanager would write:
/etc/resolvconf/run/interface/NetworkManager on my system.

Mathieu Trudel
mathieu tl gmail com