[lug] funky portforwarding ssh tunneling problem

[Hugh Brown]

Does this require that mainframe be capable of accepting ssh connections?

Currently, all I can count on is the mainframe accepting telnet connections
and two linux boxes that I have complete control over.

Hugh


"dan radom"
> 
> It seems my first reply didn't make it to the list for some reason.  What you need to do is...
> 
> ssh -L5000:mainframe:23 user at linuxserver
> 
> What you have says forward localhost (-L) to localhost.  that won't work :)
> 
> Here's what I use...
> 
> ssh -2 -L9110:pop:110 -L 9111:pop:25 -L8080:webproxy:80 -L7326:icb:7326 dradom at ssh.redback.com
> 
> dan
> 
> 
> * Hugh Brown (hugh at vecna.com) wrote:
> > I have an old legacy mainframe that only accepts telnet connections.  I
> > want to secure as much of the traffic to it as I can.  So, I am putting a
> > linux box next to it (on the same subnet) and I am setting up an ssh tunnel
> > to the linux box.  I want to use the linux box to forward that port to the
> > mainframe.
> > 
> > client<----ssh tunnel----->linuxserver<---portforward--->mainframe
> > 
> > I want to be on the client and type `telnet localhost 5000` and have it
> > make it to the mainframe with the data encrypted most of the way.
> > 
> > on client I have done this:
> > 
> > ssh -L 5000:localhost:23 linuxserver
> > 
> > on the linux server I tried allowing access on the telnet port and doing
> > this
> > 
> > ipmasqadm portfw -a -P tcp -L linuxserver 23 -R mainframe 23
> > 
> > but I am having no luck with the linuxserver to mainframe jump.
> > 
> > I am not dead set on using ipchains and ipmasqadm but I do need to be able
> > to encrypt the traffic from client to linuxserver and to be able to 
> > 
> > client% telnet localhost 5000 
> > 
> > and get exactly the same thing as if I had done:
> > 
> > client% telnet mainframe
> > 
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------------------------------------
System Administrator/Unix Consultant
hugh at vecna.com
Vecna Technologies, Inc
6525 Belcrest Rd, Suite 612
Hyattsville MD, 20782
301.864.7253
http://www.vecna.com