IIS 5 Host Headers not working

Tech-Archive recommends: Fix windows errors by optimizing your registry

From: Shane Mann (smann_at_lhwh.com)
Date: 09/08/04 

Date: Wed, 8 Sep 2004 15:52:28 -0400

Dear Helpful Souls,

I have been banging my head on this one for around 8 hours now. I have a
IIS5 server sitting on 1 ip address.
There are 5 web sites configured on this server ( the default and 4
others ). All are using host headers; each
having a unique host header for each site. 3 of them work concurrently (the
default and 2 others). I mean,
I can send requests for any of those 3 in any order during a 5 min interval
and access all concurrently.
However, there are 3 sites that seem to want to "fight" for precedence. 1 of
this "fighting" trio (the one loaded first),
will work concurrently in the afformentioned "concurrent" group while the
other two of the "fighting" trio don't
load properly if you try to visit them after first visiting the other.

A figure may help to show the problem.

Site 1 ----- Works regardless of which loads first or whatever
(concurrent group)

Site 2 ----- Works regardless of which loads first or whatever
(concurrent group)

Site 3 ----- This will work with the other two if it is loaded before the
others in this "fighting" group.

Site 4 ----- This will work with the other two if it is loaded before the
others in this "fighting" group.

Site 5 ----- This will work with the other two if it is loaded before the
others in this "fighting" group.

So essentially 2 of the sites wont be accessible at any time if you connect
to 1 of the 3 that like to "fight" first.
Of course, after a 5 min ( or so I think) timeout they work. So I was
thinking this is a keep-alive issue.
I checked the Microsoft Knowledge Database and found a suggestion for being
updated to SP4 on Win2k
to fix this. We are up to date. I even went so far as to disable keep-alives
and connect timeout in each of the
sites just to figure this out. Nothing changed. For some reason, 3 of these
sites get confused and IIS5 sends
the request to the wrong Web Site.

All of the sites are configured identically. Using unique http host headers,
all unassigned, and port 80.
Maybe I'm just missing something.

If this isn't clear or anyone can help please let me know for it would be
much appreciated. I'll be
searching for more clues until then.

Thanks For Your Time,
Shane