name resolution problem when using wired connection for VPN

[Johnathan Bailes]

On Thu, 03 Mar 2005 16:15:47 -0800, Rick Stevens
<rstevens at vitalstream.com> wrote:
> Scot L. Harris wrote:
> > On Thu, 2005-03-03 at 14:06, Scot L. Harris wrote:
> >
> >>On Thu, 2005-03-03 at 13:19, Rick Stevens wrote:
> >>
> >>>Scot L. Harris wrote:
> >>>
> >>>>This is an odd problem.
> >>
> >>>Did you check iptables and make sure that it's not blocking eth0 stuff
> >>>(the wireless is probably wlan0 and may be wide open).
> >>
> >>Good idea!  Will check that.  The wireless comes up as eth1 and the
> >>wired connection is eth0.  But it could be something in iptables.  Will
> >>check that.
> >
> >
> > Don't see anything in iptables that would block name resolution when the
> > VPN is active on the wired port.
> >
> > I tried disabling iptables as well and no change.
> >
> > I forgot to include in the first message that IP connectivity works with
> > VPN and wired connection.  I can ping the name servers but queries time
> > out.
> 
> Hmmm.  Interesting.  Normally a VPN is set up point-to-point.  Is the
> DNS server on the network that you're VPNing (is that a word?) to?
> 
> The other thing is the default route.  You didn't say if both interfaces
> are active when DNS doesn't work.  I'd suspect that the default route
> got wonked when eth0 came up with the VPN and you aren't actually
> getting to the DNS server you think you are.

Wireless routers can many time screw name resolution up.  

You need to go into your network configuration and try to explicitly
name the alternate name servers that are provided by your ISP or
company.

This may not be your issue so please correct me if this is not the
case but wireless routers name this themselves like 192.168.0.1 as the
main name server.

But they also get out of whack sometimes and suddenly dns resolution
starts failing everywhere.

Can you reach your regular dns servers at all from your vpn connection?