Monitoring plugin challenge-response requests – Effects Forum

I recently learned about C/R copy protection and would like to know when a plugin phones home.
Years ago I had a firewall that ask me for authorization every time any application would try to connect to the internet–it was exhausting. Do you know of any lightweight program that just keeps a log or just shows real-time who’s trying to connect? I don’t want a firewall, just a snitch, maybe even something I don’t need to install?