Check the network connections settings for your operating system.
The connection to the terminal should be the only active connection. (In normal operation, it is best to have only one active connection.)
To check this:
On a Windows PC, select Start > Control Panel > Network Connections. If you see an open connection other than the terminal connection, right-click on the connection and select Disable.
On a Mac, simply make sure that the wireless and Bluetooth interfaces are disabled.