How can I make a simple ad-hoc port-redirect in Linux?

Question

I would like to make a port on a local Linux machine redirect to another ip address:port. I can currently achieve this with a ssh tunnel and sshing into myself, however I am sure there is more elegant way of doing this.

I am looking for something temporary and non-permanent. AKA easy to undo/remove.

Thanks!

Answer 1

SSH is a good choice, but netcat may also give you what you want.

See the generic tcp proxy section of this page. http://www.stearns.org/doc/nc-intro.v0.9.html

Basically the suggestion is to use a command like this.

mknod backpipe p
nc -l -p 80 0<backpipe | tee -a inflow | nc localhost 81 | tee -a outflow 1>backpipe

If this is something you do regularly, it should be really easy to put it all into a script which accepts arguments.

Answer 2

No, actually, SSH tunneling is probably your best option in general, especially given your "temporary and non-permanent" criteria.

Answer 3

If redirection need once (or some times ocassionally) - ssh best

"There is nothing more permanent than temporary." - proverb

But if temporary must live over many reboots - iptables look better.

But if some manipulations with data (logging for example) required - Netcat can be useful