Some ISP's having problem with my www subdomain

Bill bill at lucidsage.com
Wed Feb 25 23:52:26 UTC 2004


This is quite strange and I wonder if anybody can offer me some
advice, knowlege, or help.

I run a website called lucidsage.com, hosted by Yahoo (not open yet,
still under construction).

I have noticed that there are times when I cannot hit:
www.lucidsage.com but CAN hit lucidsage.com (without the www
subdomain). When I can't hit www.lucidsage.com, I get an error in
Internet Explorer stating that it could not resolve the address.

The difference 'appears' to be the ISP I happen to be using when I try
to hit the page. For example, I used to be able to make the problem
manifest itself from my office but not at home (different ISPs). If I
call up a friend (who is using a different ISP) and they try, they can
successfully hit both versions of the address.

In talking to Yahoo, they obviously claim that everything is perfect
on their end since they themselves can hit both www.lucidsage.com and
lucidsage.com and that the problem must be elsewhere. Unfortunately,
I'm not familiar enough with how DNS works to know if they are correct
or not.

I did get one clue that I suspect might hold the answer. As I
mentioned earlier, I used to have this problem when trying to access
the site from my office. Our IT staff found a problem where some of
our DNS queries were being dropped because our firewall was limiting
UDP packets to 512 bytes but our Microsoft Windows Server 2003 was
configured to allow packets greater than 512. When hitting a large
site like Yahoo, whose DNS queries I 'assume' can contain
significantly more data than smaller sites, those queries were being
dropped because they were being sent in packets greater than the 512
limit on the firewall. The following microsoft article discusses this
problem:

http://support.microsoft.com/default.aspx?scid=kb;en-us;828263

Before our IT dept fixed this, I had trouble accessing subdomains such
as mail.yahoo.com but could successfully access yahoo.com. After the
fix, I was able to access subdomains successfully.

Could this same thing be happening with other ISPs? For example, a
friend of mine using CompuServe cannot access www.lucidsage.com but
CAN access lucidsage.com. Is it likely CompuServe (and who knows how
many other ISPs) are having a problem like the one mentioned above?

Any thoughts or ideas?

Thanks.


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