Is there any programs (preferably free or open source) that can monitor network activity and display it in real time as connections open/close? Idealy i would want something that i can set to display activity on specifc ports, or from specfic ip ranges and not only display the origin ip and destination port, but also resolve the ip and such too. Are such programs real? or are they just fancy things used in movies to make network stuff seem more exciting when theres a scene about it in a movie?