How to Install SSH on Ubuntu: A Step-by-Step Guide

Secure Shell (SSH) is a cryptographic network protocol that allows secure communication between two computers. It is commonly used for remote access to a computer or server. In this guide, we will show you how to install SSH on Ubuntu.

Prerequisites

Before we begin, ensure that you have the following:

A computer running Ubuntu operating system
A user account with sudo privileges

Step 1: Update the System

The first step is to update the system to ensure that all the packages are up to date. Open the terminal and type the following command:

sudo apt update

Step 2: Install SSH

To install SSH, run the following command in the terminal:

sudo apt install openssh-server

This command will install the SSH server on your Ubuntu system.

Step 3: Check the Status of SSH Service

After installing SSH, check the status of the SSH service with the following command:

sudo systemctl status ssh

If the SSH service is running, you will see the following output:

● ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2021-08-02 15:26:48 UTC; 2min 45s ago
       Docs: man:sshd(8)
             man:sshd_config(5)
    Process: 1668 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
   Main PID: 1669 (sshd)
      Tasks: 1 (limit: 2361)
     Memory: 3.9M
     CGroup: /system.slice/ssh.service
             └─1669 /usr/sbin/sshd -D

If the SSH service is not running, you can start it by running the following command:

sudo systemctl start ssh

Step 4: Configure SSH

By default, SSH is configured to allow password authentication. However, it is recommended to use key-based authentication for security reasons. To configure SSH to use key-based authentication, follow these steps:

Create a new SSH key pair on your local machine by running the following command:
```
ssh-keygen
```
Copy the public key to the remote server by running the following command:
```
ssh-copy-id user@server_ip
```
Replace user with the username of the remote server and server_ip with the IP address of the remote server.
Test the SSH connection by running the following command:
```
ssh user@server_ip
```
If the connection is successful, you will be logged in to the remote server.

Conclusion

In this guide, we have shown you how to install and configure SSH on Ubuntu. SSH is a powerful tool that allows you to securely access a remote server. By following the steps in this guide, you can set up SSH on your Ubuntu system and use it to connect to remote servers.