X thro ssh

[Saravana Kumar]

STYMA, ROBERT E (ROBERT) wrote:

>> 
>> Hi fellow admins,
>> 
>> I posted to this fedora.desktop and was redirected.
>> 
>> I have a peculiar requirement. We have two offices. People from second
>> office(say #2) want to connect to the server in first
>> office(say #1). They
>> want to run the GUI applications in the office #1 server from
>> office #2.
>> 
>> I tried to do this with VNC server and it works fine. But VNC
>> is goes thro
>> unencrypted(open) connection. Is there a way to do this in a secured
>> way(read that xdmcp is not possible as it uses UDP).
>> 
>> Inside our network(LAN) if connect from one system to other
>> thro ssh and
>> start an gui application that application shows up in the client. This
>> doesn't happen when i connect to server and start gui
>> apps(says display not
>> set). iptables runs in the server. Do i have to open any port
>> for that?
>> 
>> Any help or pointer in this regard is appreciated.
>> 
> You can use port forwarding within SSH to accomplish this
> task with VNC.  In a nutshell, you port forward some port near 5900
> (the vnc port) on the local machine to port 5900 on the machine
> running the vnc server.  This is done in your ~/.ssh/config file.
> For example:
>  LocalForward 5925 192.168.0.5:5900
> 
> You then run:
> vncclient localhost:25
> and it will connect through the secure tunnel to port 5900 on the
> target machine.  In the example 192.168.0.5
> 
> For X, the task is even easier.  Run:
> ssh -X -Y remote_machine.my.domain
> (where remote_machine.my.domain is the other machine)
> and X will be forwarded back to the local machine.
> If this does not work, check the /etc/ssh/sshd_config to
> make sure X11 tunnelling is allowed. (search for X11 in the file).
> 
> Bob Styma
> 
Thanks For the help Bob.

Let me put on what i did from first. 

In the beginning(before posting here) i took two systems(rose & glob) to
test how this works. Both are FC4 systems and the default(X11Forward yes in
sshd_config) is unchanged. I connect from rose to glob thro ssh(ssh
rose.mydomain.com) and say xclock the app shows up in rose. But when i
connect from glob to rose thro ssh(ssh glob.mydomain.com) and say xclock it
wont work. This is annoying. Any idea where i am going wrong. As both are
inside lan there is no firewall in them. i can connect in text mode from
each other.

I am going to try what you said in a short while and post the results here.

Thanks Again,

regds,
SK