Setting Up SSH

To SSH into any Ubuntu computer, including the Raspberry Pi, you must set up the OpenSSH Server.

Steps to Install & Setup:

1. Update the System:
   Run the following commands:

   sudo apt update
   sudo apt upgrade
   

2. Install the OpenSSH Server:
   Run the following command:

   sudo apt install openssh-server
   

3. Configure Firewall Rules for SSH:
   Check the status of UFW: sudo ufw status. If UFW is inactive, enable it with the following command: sudo ufw enable. Next, allow inbound SSH connections to the firewall:

   sudo ufw allow ssh
   

4. Change the Default SSH Port:
   Typically, the default port is 22, but we will be changing it to increase security. First, backup the original SSH config:

   sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
   

   Then, access the config file:

   sudo nano /etc/ssh/sshd_config
   

   Find the line Port 22, change 22 to a number between 1024 and 65535, and remove the #.

5. Configure Firewall Rules for the Custom SSH Port:

   sudo ufw delete allow ssh
   sudo ufw allow <# from step 4>/tcp
   

6. Restart the SSH Service:

   sudo systemctl restart ssh
   

7. Verify the Configuration:

   sudo systemctl status ssh
   

You should now be able to SSH using openssh-server:

ssh -p <# from step 4> <username of account on device>@<ip of device>

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