One of the important issue with Windows Server Updates Service (WSUS) Administration is troubleshooting WSUS Server for downloads. You may encounter situations where WSUS Synchronization fails.
We will take a look at the proxy settings.
Most of the times, the culprit is the proxy server where in you have authentication defined on outgoing web proxy requests. This means Anonymous access for proxy is disabled. If you are using ISA Server as your proxy server, then you must create an anonymous access rule for the following windows update websites.
The procedure is explained on http://support.microsoft.com/default.aspx?scid=kb;en-us;885819.
And now, you have to configure WSUS to Use user credentials to connect to the proxy server. With this option enabled, you have to enter the username, password & domain of the user account which is having internet access via proxy server. You can also Allow basic authentication but then, remember, password is sent in clear text which is a security threat…We are using WSUS to patch the security threats!!
i). On your WSUS server, click Start, point to All Programs, point to Administrative Tools, and then click Microsoft Windows Server Update Services.
ii). On the WSUS console toolbar, click Options, and then click Synchronization Options.
iii). In the Proxy server box, click Use a proxy server when synchronizing, and then enter the server name, and port number of the proxy server in the corresponding boxes.
iv). If you want to connect to the proxy server under specific user credentials, click Use user credentials to connect to the proxy server, and then enter the user name, domain, and password of the user in the corresponding boxes.
v). Under Tasks, click save settings, and then click OK when the confirmation box appears.
vi). Synchronize now.