Re: [tlug] Re: Absurd DNS failures.

["Norman Diamond" <ndiamond@example.com>]

"Michael Doughty" <tlug@example.com> wrote:

> A properly functioning DHCP script will populate /etc/resolv.conf with the
> proper name servers provided your DHCP provides them in its response.

My ISP's DHCP servers omit mention of DNS servers, so I had to configure
them manually in dial-up settings under both Linux and Monopolysoft systems.
But in both cases they get applied automatically at the time of dialling.

> Actually, if you dig @ the nameservers he provided, microsoft.com comes
> back in a flash.  No problems.

That depends on who "you" is.

> Now, for the reason I actually bothered to post, I have had similar issues
> with responses from certain sites(Apple's Sherlock, google.com, yahoo.com)
> with my internet connection.

Is akadns.net involved in all of those?  More on this in a moment.

> Turned out that my problem was I was going through a LinkSys firewall/
> router thing that was causing weird issues.  If I bypassed the linksys
> device everything was golden.  And sometimes, everything worked fine
> even with the LinkSys device in the loop, but other times google.com,
> yahoo.com, and a few other sites were simply inaccessible.
>
> I scoured the web but couldn't find any references from
> anyone else having this issue.  If this were just the result of the
> linksys device, I should have found a large number of reports.  This
> leads me to believe Jens SpinNet has something slightly odd with their
> infrastructure.

I'm beginning to think that it isn't JENS but it is some combination of
firewall stuff and akadns.net.  After I opened up my SuSE firewall /
iptables to allow all packets to and from the world's UDP and TCP port 53's,
the firewall should no longer be part of the problem, but maybe it still is,
just as it was with your LinkSys router.

Today's funny observations include the fact that www.yahoo.com is a CNAME
for www.yahoo.akadns.net, but www.yahoo.com has completely different IP
addresses than www.yahoo.akadns.net has.  (Of course I had to go back to
Monopolysoft Windows to get the IP addresses for www.yahoo.com.)  Returning
to Linux and using Konqueror, I could view www.yahoo.akadns.net by typing
its name instead of an IP address.  But it tried to load images from
www.yahoo.com so those failed.  And then after that, DNS lookups on
www.yahoo.akadns.net started failing too.  But I could still get to
www.yahoo.co.jp by name.  Curiouser and curiouser.

(By the way akadns.net isn't quite the same as akadns.com.  For a short
while I accidentally tried querying the name servers of akadns.com but they
were telling me to look at the world's root servers even for
www.microsoft.akadns.net.  When I tried querying the name servers of
akadns.net sometimes they were responsive for domains that they serve.  I
think I was using Monopolysoft Windows at the time of doing these
experiments though.)

-- Norman Diamond