socat - socat is a relay for bidirectional data transfer between two independent data channels.

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.

PortMapper - Do you need to map a specific TCP or UDP port on your machine to another port on another machine?

tcpdump - tcpdump is a common packet analyzer that runs under the command line.

Simple Port Forwarding - Simple Port Forwarding works with WebPages and not directly with your router.

tcpflow - tcpflow, a TCP Flow Recorder, is a program that captures data transmitted as part of TCP...