You need to be connected to a switchport that gives you ALL the network traffic or at least the traffic on your outbound connection. Otherwise you are only going to be able to capture the traffic that your switchport assigns to you/your computer.
You will have to consult your switch's documentation on how to accomplish this, some manufacturers use different terms like mirror, monitor, tap, and some may accomplish slightly different functionality.
-Kevin
/*“ I am looking for a lot of men who have an infinite capacity to not know what can't be done. ” -- Henry Ford */
