[thelist] Arguing with my ISP over DNS problem

[Mark Groen]

----- Original Message ----- 
From: "Ken Schaefer" <>
To: <thelist at lists.evolt.org>
Sent: August 11, 2004 12:21 AM
Subject: Re: [thelist] Arguing with my ISP over DNS problem

> A lot more things than just "web browsers" use DNS. On any network
> now, how do you think a client machine contacts a server for
> resources? DNS. Doesn't matter if it's *nix, MacOS or Windows -
> everything uses DNS to find everything

Agreed abviously, except they all don't need to cache it.

> But you don't even know whether the DNS cache has anything to do
with it...

Ummm, nope, that was the original problem exactly to start with, the
local XP cache showed the wrong IP. The XP DNS cache had the wrong
entries and although cleared it still wanted to go to the wrong www
server first.

> If the DNS cache was the problem, then changing the DNS servers to
> your own wouldn't have solved the problem - there would still be
> incorrect entries in the cache, and those would still be used by
the
> browser rather than your DNS server's correct entries.

You can specify which servers you want to go to first for a lookup on
a domain via the browser through the TCP/IP properties, bypassing the
machines internal cache. Entered my own nameserver (at The Planet in
Texas) because I knew it was correct.

I live on an island with a few thousand other people and we all share
the same switches and copper going under the ocean to the continent
and this was happening on just a few XP or ME machines consistently
over the course of two days (three or four days after propagation).
Win98, Linux, Mac were all okay.

> Quick follow up. If this is still a live issue, I'm happy to look
at an
> Ethereal capture from the client that is exhibiting the problem.

Temporarily changing the settings on the cranky puters to my own
nameserver fixed it right away. Thanks for reminding me about
Ethereal Capture though, a normal traceroute didn't tell me much and
actually capturing the packets might tell me more.

As mentioned, this is an issue confined to just a couple XP machines
out of many so it's not really a *big* problem (small island) because
it's an easy fix and the fix is done. A mystery though, so thanks
again for the hint to check the actual packets and I'll follow up
after figuring out what the heck was going on with these isolated
puters.

cheers,

               Mark

MG Web Services
Web Site Hosting and Development
www.mgwebservices.ca
604-780-6917
Bowen Island, B.C., Canada