creating a good test environment
 

Hello,
I have installed a test server where I want to test stuff before modifying/installing on the production server.

My question is: how can I make tests without disturbing the network users. For example: I modify samething on samba or sendmail. How can I test without disturbing the users who want to send emails or use shares on the domain at that moment?

If possible have a completely standalone server with seperate clients from the main network.