Proxy-to-Proxy Authentication Error After You Install IIS Security Patch (309562)

The information in this article applies to:

Microsoft Internet Information Services 5.0
Microsoft Proxy Server 2.0

This article was previously published under Q309562

SYMPTOMS

After you install the IIS security patch that is described in Q301625, proxy-to-proxy authentication that is based on NTLM may not work, and the following error message may be generated from a Microsoft Internet Explorer client:

Error 12201 A chained proxy server or array member requires proxy-to-proxy authentication. Please contact your server administrator.

Event Log:
Event ID 139 Type Error
Source: WebproxyServer
Proxy Server IP address of upstream proxy requires proxy to proxy authentication. Proxy server PXNT01 is not configured to do so.

This error message may be generated if you have an array (or chain) of proxy servers, and the servers are configured to use NTLM authentication.

CAUSE

This problem is caused by a regression in one of the security hotfixes in IIS.

WORKAROUND

To work around this problem, do not use the NTLM authentication method between proxy servers in an array or chain.

RESOLUTION

IIS Version 5.0 on Microsoft Windows 2000 Server

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:

   Date           Version              Size     File name
   ---------------------------------------------------------
   10-28-2001     5.0.2195.4555 shp    333,072  Asp.dll
   10-28-2001     5.0.2195.3649 shp    299,792  Fscfg.dll
   10-28-2001     5.0.2195.4555 shp      8,464  Ftpctrs2.dll
   10-28-2001     5.0.2195.4555 shp      6,416  Ftpmib.dll
   10-28-2001     5.0.2195.4555 shp      9,488  Httpmib.dll
   10-28-2001     5.0.2195.4555 shp     13,584  Infoadmn.dll
   10-28-2001     5.0.2195.4555 shp    246,032  Infocomm.dll
   10-28-2001     5.0.2195.4555 shp     62,736  Isatq.dll
   10-28-2001     5.0.2195.3649 shp      3,584  Spmsg.dll
   10-28-2001     5.0.2195.4555 shp      7,440  W3ctrs.dll
   10-28-2001     5.0.2195.4560 shp    348,432  W3svc.dll

STATUS

Microsoft has confirmed that this is a problem in Microsoft Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 3.

MORE INFORMATION

For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install Windows 2000 and Windows 2000 hotfixes at the same time, click the article number below to view the article in the Microsoft Knowledge Base:

249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes

For additional information on how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot

Modification Type:	Minor	Last Reviewed:	9/26/2005
Keywords:	kbHotfixServer kbQFE kbbug kbfix kbWin2000PreSP3Fix kbWin2000sp3fix KB309562