a.d.stribblehill at durham
Jan 27, 2000, 4:08 AM
Post #7 of 8
The way forwarding works is this:
ssh (client) run on 'smallbox' is asked to connect to 'bigbox'. It
looks at /etc/ssh/ssh_config then at the ~/.ssh/config file
(allowing the latter to override the former's defaults).
It connects to 'bigbox'.
If ssh (client) has X forwarding enabled, it tries to open an
encrypted tunnel from smallbox:0.0 to bigbox:10.0. (If this is
used, it tries :11 etc). This will only work if bigbox allows X
forwarding (it looks in /etc/ssh/sshd_config). Assuming bigbox
lets it have bigbox:10.0, the connection has $DISPLAY set to
If in this new window, you run 'xterm', it makes a connection with
bigbox:10.0 which is tunnelled through to smallbox's display.
Disclaimer: I'm not very familiar with SSH internals so this is
just partially-educated guesswork.
Systems Programmer, IT Service, University of Durham, England