Remote access with SSH in Raspberry Pi - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does SSH stand for and what is its main purpose?

SSH stands for Secure Shell. It is used to securely connect to another computer over a network, allowing you to control it remotely.

beginner

Which command do you use on your computer to connect to a Raspberry Pi via SSH?

You use the command ssh username@ip_address, where username is the Raspberry Pi user and ip_address is its network address.

beginner

Why is it important to change the default password on your Raspberry Pi before using SSH?

Changing the default password helps protect your Raspberry Pi from unauthorized access, since SSH allows remote control and the default password is widely known.

intermediate

What is the role of the SSH key pair in remote access?

An SSH key pair consists of a private key (kept secret) and a public key (shared with the Raspberry Pi). It allows secure login without typing a password each time.

beginner

How can you find the IP address of your Raspberry Pi on your local network?

You can use the command hostname -I on the Raspberry Pi or check your router's connected devices list to find its IP address.

What is the default port number used by SSH?

A 22

B 80

C 443

D 21

SSH uses port 22 by default to establish secure connections.

Which of these commands initiates an SSH connection to a Raspberry Pi with IP 192.168.1.10 and username 'pi'?

A ssh 192.168.1.10 pi

B connect pi 192.168.1.10

C ssh pi@192.168.1.10

D remote pi@192.168.1.10

The correct syntax is ssh username@ip_address.

Why should you avoid using the default 'pi' user password when using SSH?

A It is slow to type

B It causes connection errors

C It disables SSH

D It is well-known and can be a security risk

Default passwords are widely known and can let attackers access your Raspberry Pi.

What does the command ssh-keygen do?

A Connects to a remote SSH server

B Generates a new SSH key pair

C Changes the SSH port

D Lists connected SSH clients

ssh-keygen creates a new pair of SSH keys for secure login.

If you cannot connect to your Raspberry Pi via SSH, what is a common first step to troubleshoot?

A Check if SSH is enabled on the Raspberry Pi

B Restart your computer

C Change your computer's IP address

D Unplug the Raspberry Pi

SSH must be enabled on the Raspberry Pi to accept remote connections.

Explain how you would securely connect to a Raspberry Pi using SSH from your computer.

Think about the command you type and what needs to be set up on the Raspberry Pi.

Describe the benefits of using SSH key pairs instead of passwords for remote access.

Consider how keys improve safety and convenience.

Practice

1. What is the main purpose of using SSH with a Raspberry Pi?

easy

A. To securely access and control the Raspberry Pi remotely

B. To install new hardware on the Raspberry Pi

C. To increase the Raspberry Pi's screen brightness

D. To connect a keyboard directly to the Raspberry Pi

Solution

1. Step 1: Understand SSH functionality

   SSH (Secure Shell) is a protocol used to access devices remotely and securely over a network.

2. Step 2: Identify SSH use with Raspberry Pi

   Using SSH with a Raspberry Pi allows you to control it from another computer without needing a monitor or keyboard attached.

3. Final Answer:

   To securely access and control the Raspberry Pi remotely -> Option A

4. Quick Check:

   SSH = Secure remote control [OK]

Hint: SSH is for secure remote control of devices [OK]

Common Mistakes:

• Confusing SSH with hardware installation
• Thinking SSH changes screen settings
• Assuming SSH requires physical keyboard connection

2. Which of the following is the correct syntax to connect to a Raspberry Pi using SSH?

easy

A. connect username@ip_address

B. ssh ip_address@username

C. ssh username@ip_address

D. ssh -connect username ip_address

Solution

1. Step 1: Recall SSH command format

   The standard SSH command to connect is ssh username@ip_address, where username is the Pi's user and ip_address is its network address.

2. Step 2: Check each option

   Only ssh username@ip_address matches the correct syntax exactly. The other options use incorrect commands or order.

3. Final Answer:

   ssh username@ip_address -> Option C

4. Quick Check:

   SSH command = ssh username@ip_address [OK]

Hint: SSH command always uses ssh username@ip_address [OK]

Common Mistakes:

• Swapping username and IP address order
• Using wrong command like 'connect'
• Adding extra flags incorrectly

3. What will happen if you run the command ssh pi@192.168.1.10 on your computer, assuming SSH is enabled on the Raspberry Pi at that IP?

medium

A. The Raspberry Pi will reboot automatically

B. You will connect to the Raspberry Pi's command line remotely

C. You will see the Raspberry Pi's desktop GUI on your computer

D. The command will fail because SSH does not use IP addresses

Solution

1. Step 1: Understand SSH connection effect

   Running ssh pi@192.168.1.10 tries to open a secure shell session to the Raspberry Pi user 'pi' at that IP address.

2. Step 2: Identify expected result

   If SSH is enabled and the IP is correct, you get a command line prompt to control the Pi remotely. It does not reboot or show GUI.

3. Final Answer:

   You will connect to the Raspberry Pi's command line remotely -> Option B

4. Quick Check:

   SSH command opens remote terminal [OK]

Hint: SSH opens remote terminal, not GUI or reboot [OK]

Common Mistakes:

• Expecting graphical desktop via SSH
• Thinking SSH reboots the device
• Believing SSH cannot use IP addresses

4. You try to connect to your Raspberry Pi with ssh pi@192.168.1.10 but get the error: Connection refused. What is the most likely cause?

medium

A. You typed the username incorrectly

B. The Raspberry Pi is out of power

C. The IP address is for a different device

D. SSH is not enabled on the Raspberry Pi

Solution

1. Step 1: Understand 'Connection refused' error

   This error means the Raspberry Pi is reachable but not accepting SSH connections, often because SSH is disabled.

2. Step 2: Evaluate other options

   If the Pi was off, you'd get no response. Wrong username usually prompts for password or denies access, not connection refused. Wrong IP would cause timeout, not refusal.

3. Final Answer:

   SSH is not enabled on the Raspberry Pi -> Option D

4. Quick Check:

   Connection refused = SSH disabled [OK]

Hint: Connection refused means SSH service is off on Pi [OK]

Common Mistakes:

• Assuming power off causes connection refused
• Confusing username errors with connection refusal
• Thinking wrong IP causes refusal instead of timeout

5. You want to securely connect to your Raspberry Pi from outside your home network using SSH. Which step is essential to make this work?

hard

A. Set up port forwarding on your home router to the Pi's IP and port 22

B. Change the Raspberry Pi's username to 'admin'

C. Disable the Raspberry Pi's firewall

D. Connect the Raspberry Pi directly to the internet without a router

Solution

1. Step 1: Understand remote SSH access outside local network

   To access the Pi from outside your home, your router must forward incoming SSH requests (port 22) to the Pi's local IP address.

2. Step 2: Evaluate options for secure remote access

   Changing username or disabling firewall reduces security. Connecting Pi directly to internet is unsafe and usually not possible.

3. Final Answer:

   Set up port forwarding on your home router to the Pi's IP and port 22 -> Option A

4. Quick Check:

   Port forwarding enables external SSH access [OK]

Hint: Port forward router port 22 to Pi for external SSH [OK]

Common Mistakes:

• Thinking username change improves remote access
• Disabling firewall instead of configuring it
• Connecting Pi without router is unsafe and impractical