Additional WFE 401 errors?

Question

I recently joined another SharePoint server to the farm and have everything seemingly lined up. Testing wise I've just put an entry in the hosts file and pointed the IP at the new WFE. Additional 3rd party web parts have been installed. When attempting to access the home page it prompts for authentication, times out and re-prompts. All I'm seeing in the IIS logs are 401 errors. IIS has all the appropriate app pools running with the right credentials and the right version of ASP.NET (version 2.0) that the other WFE has.

Its not really giving me much to go on. Sample of the IIS log file:

2012-02-24 03:16:41 127.0.0.1 GET /Pages/default.aspx - 80 - 127.0.0.1 Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET4.0C;+.NET4.0E;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729) 401 1 2148074254 4004
2012-02-24 03:17:36 127.0.0.1 GET /Pages/default.aspx - 80 - 127.0.0.1 Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET4.0C;+.NET4.0E;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729) 401 1 2148074254 3738
2012-02-24 03:18:20 127.0.0.1 GET /Pages/default.aspx - 80 - 127.0.0.1 Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET4.0C;+.NET4.0E;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729) 401 1 2148074248 3800
2012-02-24 03:19:33 127.0.0.1 GET /Pages/default.aspx - 80 - 127.0.0.1 Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET4.0C;+.NET4.0E;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729) 401 1 2148074254 15

Some further information in the event logs:

A process serving application pool 'Portal' suffered a fatal communication error with the Windows Process Activation Service. The process id was '4792'. The data field contains the error number.

Also

Faulting application name: w3wp.exe, version: 7.5.7601.17514, time stamp: 0x4ce7afa2
Faulting module name: KERNELBASE.dll, version: 6.1.7601.17651, time stamp: 0x4e21213c
Exception code: 0xe053534f

Answer 1

We had the same error on our production farm during more than a week, just after a 2007->2010 migration...

More you have error like this, more your app_pool will crash and sometimes you'll have to restart them manually.

On your first log you can read: 401 1 2148074254 4004

Error type: 401.1 Your web app was offline, and users cannot join.

In our case, error (problem) was due to an error in the code (in the custom alerts).

If you don't have custom code try to see if the webapplication is started, stable and don't crash. If you have custom code... using a debug machine try to see where the application crash. Did you deploy your solutions? redo this operation or control the solutions status too.