Proxy Server Always Forwards Requests When Part of a Web Proxy Chain

ID: Q228721

The information in this article applies to:

Microsoft Proxy Server version 2.0

SYMPTOMS

When Proxy Server is part of a Web Proxy chain, it automatically forwards all requests to the upstream server without recourse to the local LAT table.

CAUSE

This is a design limitation of Proxy Server version 2.0.

RESOLUTION

This problem is resolved in Microsoft Proxy Server 2.0 Service Pack 1 (SP1). For more information about Service Pack 1, please see the following article in the Microsoft Knowledge Base:

Q238375 Proxy Server 2.0 Service Pack 1: List of Fixes

STATUS

Microsoft has confirmed this to be a problem in Proxy Server version 2.0.

MORE INFORMATION

With this fix applied, Proxy Server uses an additional registry string in HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\services\w3proxy\parameters named "RoutingExceptions." It is a semicolon-separated list of routing "exceptions." Each exception is made up of four space separated components, the first three of which describe the requests that match this exception and cause it to trigger. The format of the exception string is as follows:

<protocol> <domain> <port> <proxy>

where:

<protocol> is the protocol of the request or "*" to match all protocols

<domain> is the destination domain name of the request or "*" to match all domains or "*string" to match domains ending in the given string or the special "NODOTS" value, which matches any domain name that does not include a "." character

<port> is the decimal port number of the request or "*" to match all ports

<proxy> is the name and port number of the proxy server that this request will be routed to or the special "DIRECT" value if the matching URL should be fetched directly without chaining to another proxy.

Except for the special "DIRECT" and "NODOTS" values, strings are case insensitive.

If more than one exception matches a given request, then the first exception listed will be used.

Additional query words: routing chained firewall

Keywords :
Version : winnt:2.0
Platform : winnt
Issue type : kbbug