How to Monitor Internet Traffic on a LAN
- 1). Right-click the taskbar.
- 2). Click "Start Task Manager."
- 3). Click "Networking." The Task Manager window that is now open will show you the current traffic on the local area network to which you are connected. You can view how many users are logged onto the LAN, as well as see what percentage of the network's available Internet bandwidth is being used by looking at the Network Utilization column.
Source...