Re: preferring the DNS server of one interface over another

[Dan Williams <dcbw redhat com>]

On Tue, 2011-05-03 at 12:59 -0400, Laine Stump wrote:
> I have a laptop (currently running Fedora 13, with 
> NetworkManager-0.8.4-1.fc13.x86_64) that I sometimes use with a single 
> ethernet, sometimes with that ethernet + a VPN connection, and sometimes 
> plug in a 2nd ethernet onto a physical private network that provides the 
> same connectivity as the VPN. When the 2nd ethernet is plugged in, 
> sometimes its configured DNS servers are listed first in 
> /etc/resolv.conf, and sometimes the others are (and it can periodically 
> change, I'm assuming this happens when the DHCP lease is refreshed on 
> one interface or the other).
> 
> To avoid disruptions in service, I need to be able to force the DNS 
> server on the 2nd ethernet to always takes precedence over the DNS 
> server on the 1st ethernet (ie, that it be listed first in resolv.conf), 
> but I haven't found a way to specify that. Am I missing something, or 
> does this functionality not exist?

I don't think this functionality exists yet, as there isn't a way to say
that a specific interface or connection of the same device type as
another is always "preferred" over another yet.  Not sure what the best
way to handle this yet is...  suggestions welcome.  One that I know
would come up are priorities with the device's class so that you could
do exactly this and prefer one ethernet connection over another ethernet
connection.

Dan