ssh


Data Copy Over SSH 2

Need to transer a whole disk image to another computer over SSH? Just: dd if=/dev/sda | ssh user@host "dd of=/directory/imagefile" or with compression: dd if=/dev/sda | bzip2 |ssh user@host "dd of=/directory/imagefile" or with compression on the receiving side: dd if=/dev/sda | ssh user@host "bzip2 | dd of=/directory/imagefile" This example can be expanded easily as: cat filename |ssh user@host "dd of=/directory/filename" also works quite fine.

SSH Port Forwarding

It is actually really simple and well documented. You have a host You want to connect to, but it is behind a linux (anything that has ssh server running on should do) box. What You need to run is something like this ssh -L 3387:192.168.0.10:3389 -l user -N ssh_box on Your local client machine. 3387 - local port to use 192.168.0.10 - remote server where that service is running You need to connect to 3389 - the TCP port that remote service is running on user - ssh username of course ssh_box - ssh server Your service is behind of.

SSH Keepalive

Isn't it frustrating when You start up a SSH session and it times out. Usually at the worst possible moment. Using screen is good, but it comes to ones mind always after that dreadful timeout. OpenSSH supports a thng called keepalive - a keepalive packet is sent after a predetermined interval of inactivity so SSH sessions should not time out. Keepalive can be set on server side or client side. Client side is usually better because then all possible connections are kept alive. Client side: edit /etc/ssh/ssh_config and enable