Hi Pramod,
If you got as the following error:
ProtocolError occured trying to complete the request. The server returned a status code of : ProxyAuthenticationRequired and the status description is : "Proxy Authentication Required ( Forefront TMG requires authorization to fulfill the request. Access
to the Web Proxy filter is denied. )"
Solutions:
There are two things you can do, but maybe just one will work. In my case, solution 2 was in the end the only solution after testing and investigating half a day.
Solution 1
1. Navigate to the virtual directory of the SharePoint site, like: C:\inetpub\wwwroot\wss\VirtualDirectories\yoursitename
2. In the root you will find the file web.config. Edit this file and search for the line with <system.net>. Now copy and paste the following lines and make sure you change the value proxyaddress to the address of your own proxy server:
<system.net>
<defaultProxy enabled="true" useDefaultCredentials="true">
<proxy bypassonlocal="true" proxyaddress=http://10.1.2.3:80 />
</defaultProxy>
</system.net>
3. Save the file and restart IIS. To reset IIS, click Start > All Programs > Accessories > right-click Command Prompt, select Run as administrator, type in iisreset, and press ENTER.
Solution 2
Configure ISA/TMG to allow unauthenticated traffic to the Internet. Just add a rule which allows the SharePoint frontend server to navigate to the Internet (network External) over port 80. Rule settings:
Action: Allow
Protocols: HTTP (80)
From / Listener: hostname of your frontend server
To: External (Internet)
For more information, please refer to the following link(SharePoint 2010):
http://blog.henryong.com/2011/08/18/sharepoint-2010-converting-from-classic-to-claims-authentication-lessons-learned/
Thanks,
Lhan Han
