The proper technique for connecting a packet analyzer is dependent on the specific architecture of your network. In some cases you may need to make slight adjustments in your network to enable the analyzer to "see" the traffic you want to monitor. Below are four usual network scenarios showing proper injection procedures:
An external router/firewall with an external interface connected to some kind of Internet connection and an internal interface connected to a hub, mananaged switch, or unmanaged switch.
Or external router/firewall with an external interface connected to some kind of Internet connection and a built-in hub or switch (more likely).
Here's how to inject an analyzer into each of these scenarios:
