Linux – Daily Mysteries

Linux ssh Command Mysteries

Useful usages of linux ssh command :

with `allow agent forwarding` option
```
ssh -A root@www.theserveryouneed.com
```

Creating a tunnel using ssh

If you want to forward a port to your computer from another, and you can create a ssh connection to the computer, then creating the actual tunnel is very simple.

This exemple forwards the port 7000 from that computer to a port on our computer. In this case the local port in 5000

ssh -N -p 22 user@www.server.com -L 5000/localhost/7000

How to generate an openssh-key from a key generated by putty? (on Debian)

This was the problem that I faced these days; and the answer to it is very simple

First thing you have to do is to install putty tools in linux :

$app-get install putty-tools

Then, just generate the new private key, using puttygen program

$puttygen putty-generated-key.ppk -O private-openssh -o openssh-key-name

You see, everything is very simple.

Also, if you want to generate the public key, you can use the following command:

puttygen ‐L putty-generated-key.ppk >> authorized-key-location/public-key.pub

SSH Keys

Some useful commands in “linux” to generate a public key from a private one.

ssh-keygen -f ~/id_rsa -y > ~/id_rsa.pub

if you receive some warnings regarding users permissions about the private key file, the easiest way is to run the following command

chmod 700 id_rsa

How to synchronize two folders in linux

this days I’ve discover a very good command in linux : rsync

rsync -avHP  --numeric-ids --delete null/images/  /var/lib/jetty6/webapps/ro/images/