How to see who is currently logged on the domain controller

Is there a way to check who is currently authenticated or logon onto the domain controller? Also is there a command to kill the connection if the user is logon? Sometime there is the need to bring down the DC. If there is a command I can see who is still authenticated on active directory and kill the connection like just Novell and unix have.

 

Never had to cut the connection. Just reboot and the clients will be reconnected when it boots back up seemlessly.

 

Start>Administrative Tools>Shared Folders>Sessions. Clicking Action on the menu will give you an option to Disconnect All Sessions.

 

Try this http://www.stevemiller.net/sharewatch/