Pointing A Mac At A Software Update Server

Run Terminal while logged in as a machine administrator and at the terminal enter the command

defaults write com.apple.SoftwareUpdate CatalogURL URL

Where URL is the URL of the Software Update server. For example:

http://su.domain_name.com:8088/

So in our case :

defaults write com.apple.SoftwareUpdate CatalogURL http://sus.us.com:8088/