Subject: Re: dial-up over regular ethernet IP (xs4)
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Eric Haszlakiewicz <erh@nimenees.com>
List: tech-net
Date: 06/05/2002 19:23:15
On Wed, Jun 05, 2002 at 04:04:49PM -0400, der Mouse wrote:
> > this may be a slightly odd question, but I figured it might best be
> > asked here.  I'd like to establish a PPP-like session over a regular
> > ethernet IP connection.
> 
> Given your description, I'd say the thing to do is to use PPP over a
> pseudo-tty, with the pty backed by a program that opens a telnet (or
> similar) connection to the remote system.  (I've heard that such
> programs exist but have never seen one personally.)
	I believe pkgsrc/security/ssh-ip-tunnel will do this, or at least 
should easily be adapted to work if you only have telnet.

> If you don't control the PPP server, what you propose is approximately
> impossible to set up; if you do, you don't need to bother with PPP, you
> can just encapsulate and tunnel.  (Depending on the reasons behind the
> on-campus requirement, you may need to encrypt to satisfy the security
> needs the requirement is there to address.  POTS dialup is
> significantly harder to tap than random network connections.)
	Well, all you really need is any on-campus machine that you can log into.
If you've got that, then you can run a tunneling daemon of some sort to handle
connections from your machine.  I'm not sure, but it sounds like
pkgsrc/net/vtun might do what's needed. (i.e. i only saw the DESCR file)
	Assuming that only one-way connections are needed, it's entirely possible
to implement w/o any kernel support.

eric