What is SSH ?

What is  SSH?   Secure Shell for Any System

It is a Secure Shell used to execute commands on the Remote system. Normally we use a command prompt or Shell on the local computer. I have a windows 10 machine we can do ping , ipconfig ,tracetr ....etc. the command for daily troubleshooting in my lab from a local pc but I have another system that contains Linux ubuntu. I went and use its shell or command line interface so we have two ways either use RDP and access the terminal or the 2nd way I installed SSH on it(Linux Machine other than my pc) and access it.  

The  SSH has two Components (Both for any machine)

1-SSH Client.

2-SSH Server

SSH Client used for access SSH Server for example my pc what to access Linux machine.

My PC has only SSH Client (SSH is not installed on my pc)

I installed Terminus (as a windows command line terminal)on my windows 10 Machine.

SSH Client  instlled by issue the command  ssh. shown in blow image.

i am also installed SSH server component .(i use OpenSSH software you can diffenent one )

SSH configuration on Ubuntu from scratch

Installed OpenSSH server

sudo apt-get install openssh-server

This SSH  Server is Running ie the server service is running or not . Show Active  by using 

sudo service ssh status  OR sudo systemctl status ssh

sudo nano /etc/ssh/sshd_config     This file used to change port  default port no which is port 22

If ssh is not successful then we type sudo ufw allow ssh

After configuring the SSH client and SSH Server, We can See.