Sysdig - Sysdig is an open source, system-level exploration that capture system state and activity from a running Linux instance, then save, filter and analyze.
netcat - Netcat is a featured networking utility which reads and writes data across network connections...
lsof - Lsof lists open files for running UNIX processes. It is a
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.
htop - htop - an interactive process viewer for Unix. This is htop, an interactive process viewer for Unix systems. It is a text-mode application (for console or X terminals) and requires ncurses. Latest release: htop 2.
SmartSniff - SmartSniff is a packet sniffer that capture TCP/IP packets and display them as sequence of conversations between clients and servers.