Commands tagged ssh

dsh - Distributed shell, or dancer?s shell ;-)

you can put your servers into /etc/dsh/machines.list than you don't have to serperate them by commata or group them in different files and only run commands for this groups

dsh -M -c -a -- "apt-get update"

Once it is connected to the remote server by that ssh protocol,the mentioned command will start working on that server.

Stop tormenting the poor animal cat!

Also you should not that you need a private key not protected by a passphrase on middlehost that grants you access to securehost..

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.

copy files to a ssh server with gzip compression

middlehost allows ssh access from where you are but not securehost.

Use nice ssh piping to simulate scp through A => B => C

setting up the shell function if left as an exercise for the reader. ;-)

Agent forwarding should avoid password typing.

Useful to move many files (thousands or millions files) over ssh. Faster than scp because this way you save a lot of tcp connection establishments (syn/ack packets).

If using a fast lan (I have just tested gigabyte ethernet) it is faster to not compress the data so the command would be:

tar -cf - /home/user/test | ssh user@sshServer 'cd /tmp; tar xf -'

This starts a very basic X session, with just a simple xterm. You can use this xterm to launch your preferred distant session.

Try also startkde or fluxbox or xfce4-session.

To switch between your two X servers, use CTRL+ALT+F7 and CTRL+ALT+F8.

Directly attach a remote screen session (saves a useless parent bash process)

Redirects the contents of your clipboard through a pipe, to a remote machine via SSH.

If your firewall or proxy at your location prevents connection to a particular host or port, you can use ssh to tunnel to your home server and do it there instead.

Uses ssh as tunnel tunnel for an other connection.

-f runs ssh in the background -N tell that there is no command to run -L deals with the forwarding aspect where the first number is the local port number, the second is parameter is the name of the server to forward to and the third parameter is the port number on that server. The last part of the command is the usual ssh form consisting of the user name and remote server name

When you have to manage lot of servers, it's boring to type ssh root@myhost for each connection. Now you can type juste "s someting" and you are connected.

You can too add bash_completion script to complet with tab the name of your servers. This will be the next tips from me ;)

Optionally, you can create a new function to do this with a custom command. Edit $HOME/.bashrc and add:

myssh () { ssh $1 | tee sshlog ; }

Save it.

At command prompt:

I used this to confirm an upgrade to an SSH daemon was successful

I find it ugly & sexy at the same time isn't it ?

The SSH server configuration requires:

X11Forwarding yes # this is default in Debian

And it's convenient too:

Compression delayed

The ssh command alone will execute the sudo command remotely, but the password will be visible in the terminal as you type it. The two stty commands disable the terminal from echoing the password back to you, which makes the remote sudo act as it does locally.

Unreachable_host is unavailable from local network, but it's available from reachable_host's network. This command creates a connection to unreachable_host through "hidden" connection to reachable_host.

This command checks for the number of times when someone has tried to login to your server and failed. If there are a lot, then that user is being targeted on your system and you might want to make sure that user either has remote logins disabled, or has a strong password, or both. If your output has an "invalid" line, it is a summary of all logins from users that don't exist on your system.

Takes input from the connected terminal and dumps it to the specified file. Stop writing and close file with control + D or the end of line character. Useful for copying+pasting large blobs of text over SSH to a new machine.