some problem with tunneling
From: Nikolas Mayr (nikolas_at_pt.fh-koeln.de)
Date: Thu, 21 Aug 2003 23:39:27 +0200 To: email@example.com
let me describe what i experienced in order to find out what went wrong.
the situation: A B are computers. their users are usera and userb. B is
somewhere in the internet, A is behind a firewall/router with ip
masquerading enabled and port mapping disabled. (i have no way to
change the router's configuration). i have access to both computers.
what i wanted to do though was to remote work/configure computer A
using vnc. in order to be able to connect to A i needed a way in there.
so i used the command
ssh -R 12345:127.0.0.1:22 userb@B on computer A to give myself a way to
ssh into A (from B).
i could indeed do that using the command
ssh -p 12345 firstname.lastname@example.org on B
so in odrer to connect vnc to that copmuter i created another tunnel
(after connecting via ssh from B).
while being logged into A through ssh from B using the tunnel i created
before i typed the command
ssh -R 12346:127.0.0.1:5900 userb@B
this also did work.
the vnc server by the way has already been started on machine A.
so the next thing i did is started a vnc client on B and connected to
now i got an error message in the shell. unfortunately i can nether
recall it exactly nor recreate the situation at the moment. so my mind
tells me the error message contained "connection was reset by peer" and
something like tcp nodelay (bad memory, i know).
i have no clue what went wrong.
hopefully you can help me understand that problem.
btw: i know that i could have created a tunnel to port 5900 on machine
A directly. i chose to use the way i did it because i thought i was
able to do basically anything on machine A if i ever get logged into
thanks in advance,