Proxy Server 2.0: Error 12201 Proxy-to-proxy Authentication

 Last reviewed: December 17, 1997
Article ID: Q177063

The information in this article applies to:

  • Microsoft Proxy Server version 2.0

SYMPTOMS

When you chain or array the Microsoft Proxy Server version 2.0 servers, you may get the following error message: 

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

CAUSE

This error occurs when Encrypted (Microsoft Windows NT Challenge/Response) authentication is used to send credentials to the upstream Proxy Server or array when anonymous access is allowed on the Proxy Servers.

NOTE: This authentication option is set in the Web Proxy Service Properties by selecting Routing, Upstream Routing, Use Credentials to Communicate with Upstream Proxy Array.

RESOLUTION

Disable Anonymous authentication in the Microsoft Internet Information Server (IIS) WWW Service properties on the Proxy Servers participating in the chain or array.

Select Windows NT Challenge/Response authentication (enabled). Enabling Basic authentication is optional.

Additional query words: proxy to proxy ntlm ntcr distributed cache prx2faq frequently asked questions faq
Version : WINNT:2.0

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Last reviewed: December 17, 1997
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