On Sun, Dec 17, 2000 at 07:29:24PM -0800, opentrax@email.com wrote:

 > > TCP tunnelling.
 > > 
 > How is TCP tunneling useful?

"TCP tunneling" is really not the correct term.  It's actually
called "port forwarding", and could be used like this:

	Assume that int.foo.com is the internal web server at
	Foo, Inc.  It's behind a firewall and is not accessible
	from outside the company's internal network.

	Foo, Inc. also provides a gateway for users on the road
	(conferences, sales calls, etc.) to log into their systems
	back at the office.  Calls this ssh-gate.foo.com.

	A user on the road can use SSH's port forwarding feature
	to access the internal web server via the SSH gateway like
	so:

		laptop% ssh -L8080:int.foo.com:80 ssh-gate.foo.com

	Now on the user's laptop, he can point his web browser to
	http://localhost:8080/ and get the company's internal
	web server.

Needless to say, this is a Very useful feature.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>