Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
netcat - Netcat is a featured networking utility which reads and writes data across network connections...
TcpView For Linux - TcpView For Linux. Touch screen friendly design graphical network connections viewer for Linux.
tcpdump - tcpdump is a common packet analyzer that runs under the command line.
NetStat Agent - At whatever point you open a site association through your program or download documents, you are opening TCP/UDP connions.