SharePoint 2007 RSS Viewer - ProxyAuthenticationRequired

Question

When using the RSS Viewer webpart in SharePoint 2007, we can hit internal RSS feeds without issue but if we point to an external RSS feed we get 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 ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied. )"

I'm finding information on how to get around this but I'd like to know the best way to approach this issue such that I don't deploy something in haste that gives us problems later on.

Ideally I would like to tell SharePoint to use its service account to use the proxy when hitting external sites with the RSS Viewer webpart.

Answer 1

In the web.config for the site's web application, use:

<system.net>
  <defaultProxy>
    <proxy usesystemdefault="false"
           proxyaddress="http://10.10.10.10:8080"
           bypassonlocal="false" />
  </defaultProxy>
</system.net>

Then use the features of ISA Server to restrict outbound access as best you can (e.g. by service account). We weren't able to do this and initially tried by destination URL, however a lot of feeds don't end with .rss. In the end, we had to give the box free reign.