Http 401 entries in IIS log of SharePoint Server

Question

We are trying to fix a performance problem.

It is a WSS 3.0 solution running on Windows 2003, behind a hardware load balancer with IE6 clients. We use windows authentication with integrated security.

So far we have found that there appears to be alot of unecessary network traffic. There appears to be a pattern with 5 calls that return http 401.2, then 1 call that returns http 401.1, followed by a call that returns http 200.

Anyone know what could be generating these 401.2 errors or why there are 5 of them for each request.

Answer 1

Without seeing what, specifically, is being returned in the logs it's hard to say.

One quick way to see what's what is to browse the site from the server itself and/or another machine that is behind the firewall. If the behavior is the same as the firewall'ed behavior, that at least eliminates that as a problem.

Otherwise, some of this 401 stuff is "expected behavior" as it does take a couple/few steps for integrated authentication to get itself sorted out. Some refs:

support.microsoft.com/kb/902160
support.microsoft.com/kb/896861
support.microsoft.com/kb/871179

-Mary

Answer 2

That is normal, it is part of the pre-login handshake.

What is causing you to look at the IIS Logs? Are you suffering poor performance?