Logging DSL activity

Prior to my current DSL I had Cable with a linksys router. It was fairly easy to monitor all activity in and out of the router real time to include web sites visited , port probes and scans from the outside. Since I switched to DSL I was given a ZyXel modem which in itself acts like a Bridge and runs a private IP on the other side as opposed to the cable modem. For this reason I cannot monitor traffic coming in to see if Im being probed or being scanned. The ZyXel modem does have an internal IP with a web GUI but nothing to look at traffic real time. Does anyone know of any utility software or any type of tricks to get to what Im looking for?

Thanks