Configure Reporting Services to use proxy for Bing maps

If you work somewhere that uses a proxy server to connect you and your servers to the internet you will need to configure Reporting Services to use said proxy in order to use the Bing maps layer. Otherwise you will see something along the lines of the following message in your report, instead of a map:

The remote name could not be resolved: 'dev.virtualearth.net'

The solution is easy;

Step one
Navigate to the webconfig file for the instance of Reporting Services you want to proxy out to the internet. Typically for 2008 R2 this will be:

<drive name>\Program Files\Microsoft SQL Server\MSRS10_50.<instance name>\Reporting Services\ReportServer\web.config

Step two
Add the following xml fragment to the file - I usually add it in-between the</runtime> tag and the </configuration> tag, at the end of the file:

<system.net>

        <defaultProxy enabled="true" useDefaultCredentials="true">

            <proxy bypassonlocal="True" proxyaddress="http://<proxy server>"  />

        </defaultProxy>
    </system.net>

Save the file.

This of course assumes your server is allowed to proxy out in the first place (which it will need for Bing maps integration). You can test this by logging onto the server and firing up a browser or by asking your friendly local sysadmin...