BOL

SSH, also known as Secure Shell or Secure Socket Shell, is a network protocol that gives users, particularly system administrators, a secure way to access a computer over an unsecured network. SSH also refers to the suite of utilities that implement the SSH protocol.

Here are the commands used to connect by Secure SHell:

On the server side

sudo apt-get install ssh

sudo apt-get install openssh-server

sudo /etc/init.d/ssh start

sudo nano /etc/ssh/sshd_config

Uncomment port 22
Uncomment HostKey /etc/ssh/ssh_host_rsa_key
Uncomment AuthorizedKeysFile .ssh/authorized_keys .ssh/authorized_keys2
Set pubkey authentication to "yes"

sudo systemctl restart sshd.service # or sudo /etc/init.d/ssh reload

On the client side:
in ~/.ssh

ssh-keygen -t rsa # set passphrase or not
ssh-copy-id -i ~/.ssh/id_rsa user@100.100.10.100

--> write "yes" then password in

ssh user@100.100.10.100

--> write password --> you should be in

--> in /home/user/.ssh/config type:
Host WhateverName
HostName 100.100.10.100
User username
ForwardX11 yes
ForwardAgent yes
IdentityFile ~/.ssh/id_rsa

--> you should now be able to connect with :

ssh WhateverName