What is it ?
pbnc runs in userland and acts as a simple TCP port forwarder.
It has a single-threaded design (uses select(), does not
fork). It can handle multiple targets with an unlimited number
of clients (at least in theory), and supports simple IP-based
access control. Since pbnc works on network level, it does not
care about the application protocol. It can tunnel FTP
(control connection), SSH, HTTP and all other protocols using
TCP communication. Application-level SSL/TLS encryption is
also no problem.
I came up with this little script when I needed to forward
ports on a machine without root privileges. If you have root,
use kernel-level bouncing instead (iptables under Linux).