Three-way handshake in Computer Networks - Mini Project: Build & Apply

Understanding the TCP Three-Way Handshake

📖 Scenario: You are learning how computers establish a reliable connection over the internet using the TCP protocol. This process is called the three-way handshake. It helps two computers agree to communicate before sending data.

🎯 Goal: Build a simple step-by-step description of the TCP three-way handshake process using a list of messages exchanged between a client and a server.

📋 What You'll Learn

Create a list called handshake_steps with the exact three messages exchanged in order.

Add a variable called current_step to track the handshake progress starting at 0.

Use a loop with variable step to go through each message in handshake_steps.

Add a final message indicating the handshake is complete.

💡 Why This Matters

🌍 Real World

The TCP three-way handshake is how computers start a reliable connection before sending data, like when you open a website or send an email.

💼 Career

Understanding this handshake is important for network engineers, cybersecurity professionals, and software developers working with internet protocols.

1

Create the handshake messages list

Create a list called handshake_steps with these exact strings in order: 'Client sends SYN', 'Server sends SYN-ACK', 'Client sends ACK'.

Computer Networks

# Create the handshake_steps list with the three messages
# Your code here

Need a hint?

Remember to use square brackets [] to create a list and put each message inside quotes.

2

Add a variable to track the current step

Add a variable called current_step and set it to 0 to track which handshake message is next.

Computer Networks

handshake_steps = ['Client sends SYN', 'Server sends SYN-ACK', 'Client sends ACK']
# Create current_step variable and set it to 0
# Your code here

Need a hint?

Just create a variable named current_step and assign it the number 0.

3

Loop through handshake messages

Use a for loop with variable step to go through each message in handshake_steps. Inside the loop, update current_step to step.

Computer Networks

handshake_steps = ['Client sends SYN', 'Server sends SYN-ACK', 'Client sends ACK']
current_step = 0
# Loop through handshake_steps with variable step
# Update current_step to step inside the loop
# Your code here

Need a hint?

Use range(len(handshake_steps)) to get indexes and assign current_step inside the loop.

4

Add final handshake completion message

After the loop, add a variable called final_message and set it to the string 'Handshake complete'.

Computer Networks

handshake_steps = ['Client sends SYN', 'Server sends SYN-ACK', 'Client sends ACK']
current_step = 0
for step in range(len(handshake_steps)):
    current_step = step
# Add final_message variable with 'Handshake complete'
# Your code here

Need a hint?

Just create a variable named final_message and assign the exact string 'Handshake complete'.