[lug] Re: Problem with resolving

[Stephen Queen]

On 12/2/05, Stephen Queen <svqueen at gmail.com> wrote:
> I just changed ISP's. I now have an Actiontec DSL modem connected to
> my Linux gateway machine. The Linux gateway machine acts as my
> router/firewall. On the inside network I have 3 more linux machines.
> Two of them are running Slackware and the other is running Debian. The
> two Slackware machines seem to be working just fine. I can access the
> web just like with my old ISP. The Debian machine seems to not resolve
> outside addresses correctly.
>
> One of the first things I tried was to boot the machine with knoppix
> and configure the network with the same parameters and it worked.
>
> Booting back to Debian I then tried ssh'ing to a remote account. It
> resolved the name  correctly and allowed me to log on.
>
> I then tried a traceroute, and got the normal results.
>
> I can also do a dig to a host name and get the correct results. But if
> I enter the URL for a web site on a browser it still doesn't resolve
> correctly.
>
> I then tried to wget to a web site. It came back saying the URL
> resolved to 1.0.0.0.
> I did a dig on the same website, got the correct IP Address and tried
> again with wget using the IP address. It downloaded the index.html of
> that website.
>
> I then did a strace on wget using the URL. I could see that it does in
> fact access the nameserver but returns with the IP of 1.0.0.0.
>
> I did an arp, and it looks like my IP's do map to the correct mac addresses.

I am as confused as ever by this problem.  Yesterday I looked over the
replies I had received from my original post and was trying to find a
solution. I worked on it for several hours. I did download the
iprout.deb package on one of my Slackware machines, scp' d it over to
my Debian machine and was looking at some of my network configurations
with it. I rebooted a number of times as well. When I finished the
Debian machine still would not resolve correctly on any URL involving
port 80. I did try Dan's idea of telnetting to a URL on port 80. It
did not resolve. I have been very reluctant to blame the problem on
the ActionTec modem as two people have suggested.

I was/am at wits end, so I decided to give it a try, and just point at
the nameserver that is a real nameserver rather than the one in the
modem. BUT when I got home from work and went to try it, the machine
was already resolving correctly before I did anything. I had not
rebooted it since yesterday when it was NOT working. I then rebooted
to see if that would make it start failing again. Of course it didn't.
I guess I just run it like this until it begins to not work correctly
again.

Does anyone think they understand this behaviour? Does this maybe
re-enforce the idea that it is a flakey nameserver in the modem?

Thanks for all the input so far.

Stephen Queen