Technology Insights

Daemon In Linux To Open A TCP Port That Listens On Every IP And Logs TCP Connections

Yesterday a colleague at my company was doing some testing with a potential partner and they needed to open a TCP port on one of our development servers so an application could bind to that port. At first I wasn’t sure how I should do this since the port didn’t need to do anything but listen for incoming connections and the remote application would simply connect to that port. To get something up immediately for them I simply had our web server listen on the requested port which worked however I did not want the web server running on this port for long so I needed to come up with another solution to simply open the port, listen for connections, and possibly log those connections so we could troubleshoot if necessary. I ended up finding an application called tcpsnoop which I explain how to compile and use below.