Dave Onex replied to Dave Onex
29-Oct-09 05:28 PM

OK, after much messing around I finally figured out what was wrong.
I doubt anyone will ever encounter the same issue but for future reference
here is what caused the 401.3 errors.
I took down a large web site that I had up and running for many years.
Instead of keeping all the content, I archived it off, but of course traffic
still came to the site and this resulted in tons of 404 errors due to the
missing site.
So, what I did was put up a single static HTML page explaining that the site
was retired and thanking everyone for their years of use. My thoughts were
that all the search engines and people would see this and that would update
all the indexes with that one HTML page.
Good enough, but here is what happened - I still got a ton of 404's from
external traffic looking for pages that no longer existed.
This is where I introduced the problem and it was not ISA.
I went into IIS and changed every error page for that site to display the
single HTML file I had created. In this way, whenever anyone requested
anything that did not exist or resulted in any error they would be shown the
single HTML file explaining that the site was retired.
By doing that I introduced the error. I do not understand the mechanics
behind it but once I set all the IIS error pages back to their stock
settings all the 401.3 errors went away. Looking back on it, that was the
only change that was made since the site was active - so it made sense.