SSH tunneling (port forwarding) in Linux CLI - Mini Project: Build & Apply

SSH Tunneling (Port Forwarding)

📖 Scenario: You work in a company where you need to securely access a database server that is only accessible from the company network. You want to use SSH tunneling (port forwarding) to connect to the database from your local machine.

🎯 Goal: Learn how to create a local SSH tunnel that forwards a local port to a remote database server port through an SSH server.

📋 What You'll Learn

Create a variable with the SSH server address

Create a variable with the remote database port

Write the SSH command to create a local port forwarding tunnel

Display the SSH command output or confirmation

💡 Why This Matters

🌍 Real World

SSH tunneling is used to securely access remote services like databases or web servers that are behind firewalls or private networks.

💼 Career

Many IT and DevOps roles require setting up SSH tunnels to securely connect to remote resources without exposing them publicly.

1

Set SSH server address

Create a variable called ssh_server and set it to [e-mail] which is the SSH server address.

Linux CLI

# Create a variable called ssh_server and set it to '[e-mail]'
# Your code here

Need a hint?

Use single quotes to assign the string value to the variable.

2

Set remote database port

Create a variable called remote_db_port and set it to 5432, which is the port number of the remote database server.

Linux CLI

ssh_server='[e-mail]'
# Create a variable called remote_db_port and set it to 5432
# Your code here

Need a hint?

Assign the port number as an integer without quotes.

3

Write SSH local port forwarding command

Create a variable called ssh_command that stores the SSH command string to forward local port 6543 to the remote database port 5432 on localhost through the SSH server stored in ssh_server. Use the syntax: ssh -L 6543:localhost:5432 [e-mail].

Linux CLI

ssh_server='[e-mail]'
remote_db_port=5432
# Create ssh_command variable with the SSH local port forwarding command
# Your code here

Need a hint?

Use double quotes and variable substitution with ${variable} inside the string.

4

Display the SSH command

Write a command to print the value of the ssh_command variable to show the full SSH tunneling command.

Linux CLI

ssh_server='[e-mail]'
remote_db_port=5432
ssh_command="ssh -L 6543:localhost:${remote_db_port} ${ssh_server}"
# Echo the ssh_command variable
# Your code here

Need a hint?

Use echo "$ssh_command" to display the command.