Internet Information Services имеют счетчики производительности, которые можно использовать для мониторинга активных подключений через Интернет и FTP ...
http://technet.microsoft.com/en-us/library/cc728306%28WS.10%29.aspx
To monitor active Web and FTP connections in IIS 6.0
1.
Open Administrative Tools, and then click Performance.
2.
Right-click the System Monitor details pane, and then click Add Counters.
3.
Do one of the following:
* To monitor any computer on which the monitoring console is run, click Use local computer counters.
-or-
* To monitor a specific computer, regardless of where the monitoring console is run, click Select counters from computer, and specify a computer name or IP address.
4.
In Performance object, click:
* Web Service to monitor active Web connections.
-or-
* FTP Service to monitor active FTP connections.
5.
Click Select counters from list, and select Current Connections.
6.
Click All instances.
7.
Click Add, and then click Close.