I stumbled across this tool when I needed to redirect some outside traffic
to an inside machine (firewall of course realized with IP Masquerading...)

I took one machine that was visible from the outside and redirected
traffic coming from the outside to the inside host while keeping the
ability to connect to that server from the inside.

The following /etc/hosts.allow did the trick:

in.telnetd:     .school.edu
# Dont touch the above statement enables regular on campus telnet access
# to host.
#
# Add to lalug.org whatever hosts need access to the insidehost
in.telnetd:     lalug.org : twist /usr/sbin/redir --inetd --chost=insidehost -cport=23

The first line allows regular access from our school. The second
allows special access from that outside host to the inside machine.

Christoph Lameter, <clameter@debian.org>
