Host Logic in PAC File May Not Direct Browser to the Intended Proxy Server (258141)

The information in this article applies to:

Microsoft Internet Explorer 5.5 for Windows NT 4.0
Microsoft Internet Explorer 5.01 for Windows NT 4.0
Microsoft Internet Explorer 5.0 for Windows NT 4.0
Microsoft Internet Explorer 5.5 for Windows 98 Second Edition
Microsoft Internet Explorer 5.01 for Windows 98 Second Edition
Microsoft Internet Explorer 5.5 for Windows 98
Microsoft Internet Explorer 5.01 for Windows 98
Microsoft Internet Explorer 5.0 for Windows 98
Microsoft Internet Explorer 5.5 for Windows 2000

This article was previously published under Q258141

SYMPTOMS

When you click to select the Use automatic configuration script check box and then point the address to a .pac file that is similar to the following sample code, when you view a particular Web site you may not use the proxy server that you intend to in the .pac file.

   if(dnsDomainIs(host,"testhost"))
        return "PROXY myproxya:80";
   else
        return "PROXY myproxyb:80"

CAUSE

Under certain circumstances, Internet Explorer caches the proxy server and returns that cached proxy server instead of the server in the else branch of the code.

RESOLUTION

Internet Explorer 5.5

To resolve this problem, obtain the latest service pack for Internet Explorer version 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

276369 How to Obtain the Latest Internet Explorer 5.5 Service Pack

Internet Explorer 5.01

To resolve this problem, obtain the latest service pack for Internet Explorer version 5.01. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

267954 How to Obtain the Latest Internet Explorer 5.01 Service Pack

STATUS

Internet Explorer 5.5

Microsoft has confirmed that this is a problem in Internet Explorer 5.5. This problem was first corrected in Internet Explorer version 5.5 Service Pack 1.

Internet Explorer 5.01

Microsoft has confirmed that this is a problem in Internet Explorer 5.01. This problem was first corrected in Internet Explorer version 5.01 Service Pack 2.

Modification Type:	Minor	Last Reviewed:	9/23/2005
Keywords:	kbHotfixServer kbQFE kbbug kbfix kbIE501preSP2fix kbIE550preSP1fix kbie550SP1Fix kbQFE KB258141