Remote access with SSH in Raspberry Pi - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this SSH command?

You run this command on your local machine to connect to a Raspberry Pi with IP 192.168.1.10 as user 'pi'. What will be the output if the connection is successful?

Raspberry Pi

ssh pi@192.168.1.10

A pi@192.168.1.10's password:

B Permission denied, please try again.

C ssh: Could not resolve hostname 192.168.1.10: Name or service not known

D Connection timed out during banner exchange

💡 Hint

Think about what happens right after you run ssh with a correct IP and username.

When you connect successfully, SSH asks for the user's password to authenticate. So you see the prompt for the password.

❓ Predict Output

intermediate

What error occurs when SSH server is not running?

You try to connect to your Raspberry Pi with SSH but the SSH server is not running. What error message will you see?

Raspberry Pi

ssh pi@192.168.1.10

A Connection timed out during banner exchange

B Permission denied (publickey,password).

C ssh: Could not resolve hostname 192.168.1.10: Name or service not known

D ssh: connect to host 192.168.1.10 port 22: Connection refused

💡 Hint

If the server is off or not listening on port 22, the connection is refused.

Connection refused means the server is reachable but no service is listening on the SSH port.

🔧 Debug

advanced

Why does this SSH command fail with 'Permission denied'?

You run this command to connect to your Raspberry Pi but get 'Permission denied' error. What is the most likely cause?

Raspberry Pi

ssh pi@192.168.1.10
# You enter the wrong password multiple times.

A The Raspberry Pi IP address is incorrect.

B You typed the wrong password or the user 'pi' does not have SSH access.

C The SSH server is not running on the Raspberry Pi.

D Your local machine's SSH client is outdated.

💡 Hint

Permission denied usually means authentication failed.

If the password is wrong or the user is not allowed to login via SSH, you get 'Permission denied'.

🧠 Conceptual

advanced

What is the purpose of SSH key pairs in remote access?

Why do we use SSH key pairs instead of passwords for connecting to a Raspberry Pi remotely?

A SSH keys replace the need for an IP address when connecting.

B SSH keys slow down the connection but increase compatibility.

C SSH keys allow passwordless, more secure authentication without sending passwords over the network.

D SSH keys are used only for encrypting files on the Raspberry Pi.

💡 Hint

Think about security and convenience in remote login.

SSH keys provide a secure way to authenticate without sending passwords, making connections safer and easier.

❓ Predict Output

expert

What is the output of this SSH command with port forwarding?

You run this command to forward your local port 8080 to Raspberry Pi's port 80. What will be the output if successful?

Raspberry Pi

ssh -L 8080:localhost:80 pi@192.168.1.10

A pi@192.168.1.10's password:

B Warning: Remote port forwarding failed.

C ssh: connect to host 192.168.1.10 port 22: Connection timed out

D Local forwarding failed: Address already in use

💡 Hint

Port forwarding does not change the initial password prompt.

Even with port forwarding, SSH first asks for the password to authenticate the user.