To kill everything listening to a port: sudo fuser -k 2121/tcp

Create a hidden file called .bashrc in your home folder and add aliases for different commands as:

alias something='ssh -Y uder@server.com'

So something will always execute the command ssh -Y uder@server.com.

screen -S name
screen -ls
screen -d -r name

Detach screen from another ssh shell: screen -d -r

Keyboard shortcuts:

• ctrl+a d: leaving a screen without terminating
• exit: to terminate a screen

ssh -Y user@10.50.17.66 # login
ssh -N -f -L localhost:8889:localhost:8889 user@address # tunneling

Login to server using private key:

1. Create a private-public ssh key pair.
2. Your private key should be inside the folder ~/.ssh/
3. Change permission of the folder: sudo chmod -R 700 ~/.ssh
4. Then log in: ssh -Y username@server

sudo adduser username
sudo deluser username
sudo addgroup groupname
sudo delgroup groupname
sudo adduser username groupname
getent passwd | cut -d: -f1
getent group

sudo mount -t auto /dev/sdb /media/plato/