Simulate Restrictive Firewall

Super simplistic and well working with http://www.vakuumverpackt.de/tcptunnel/

Idea: Forward the “opened” TCP port(s) from localhost to the remote host.
Then work against localhost.

Example:

tcptunnel --stay-alive --local-port 556 --remote-port 556 --remote-host 192.168.2.67 --fork

Then connect to 127.0.0.1:556.

Important:

• --stay-alive for not closing after 1st connection.
• --fork to support parallel TCP connections.