SharePoint world of ECM and Information Management

SharePoint Tip #36. Do you know “a cause of HTTP 400 Bad Request error when login to site” ?

Sometimes, you may find that you get “HTTP 400 Bad Request” error, or “HTTP 401.1 - Unauthorized: Logon Failed” error when navigate to local SharePoint sites and asked for credentials tree times.

This mostly happens for Web sites that use Integrated Authentication and have a name that is mapped to the local loopback address. More details in KB896861.

Such situation is “behavior-by-design” and caused by Windows security updates, when authentication fails if the FQDN (fully qualified SND name) or the custom host header does not match the local computer name.

Solution: run REGEDIT and create DWORD “DisableLoopbackCheck” equal “1” in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa.

PS: I actually had all my sites inaccessible after bunch of security updates on Windows 2008 before and after installing SharePoint SP2.

Source

Have anything to add?! Send your tips to be published via this form.

Posted: Tue, Jun 9 2009 1:15 by Michael | with 2 comment(s)
Filed under: ,

Comments

Jauchter said:

I am running into a similar problem. - My share point site works internally buy no external. After checking all settings I made this registry entry and I am able to authenticate locally on the machine but still unable to get the site to pull up authentication on the outside.  Granted there could be other reasons for this but I have gone over the settings a dozen times. Would this reqistry entry effect the ability for users on the outside to connect to the share point site?

# June 11, 2009 7:34 AM

Michael said:

Who are the "externals" and how are they logging in?!

Did you extend you web app or you are in the same network?

# June 11, 2009 7:47 AM
Leave a Comment

(required) 

(required) 

(optional)

(required)