CIDR notation in Computer Networks - Mini Project: Build & Apply

Understanding CIDR Notation

📖 Scenario: You are working as a network technician setting up IP addresses for a small office network. You need to understand how to write and interpret IP addresses using CIDR notation to efficiently allocate IP ranges.

🎯 Goal: Build a simple reference guide that shows how to write an IP address with its subnet mask in CIDR notation, and how to identify the network and host parts.

📋 What You'll Learn

Create a dictionary called ip_addresses with three IP addresses as keys and their subnet masks as values.

Add a variable called cidr_suffix that holds the number of bits used for the network part.

Create a new dictionary called cidr_notation that combines each IP address with the cidr_suffix to form CIDR notation strings.

Add a final dictionary entry that explains what CIDR notation means in simple terms.

💡 Why This Matters

🌍 Real World

CIDR notation is used by network engineers and IT professionals to efficiently allocate IP addresses and manage networks.

💼 Career

Understanding CIDR notation is essential for roles in network administration, cybersecurity, and cloud infrastructure management.

1

Create the IP addresses dictionary

Create a dictionary called ip_addresses with these exact entries: '192.168.1.0' with subnet mask '255.255.255.0', '10.0.0.0' with subnet mask '255.0.0.0', and '172.16.0.0' with subnet mask '255.240.0.0'.

Computer Networks

# Create the ip_addresses dictionary with given IPs and subnet masks
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with the IP addresses as keys and subnet masks as values.

2

Add the CIDR suffix variable

Add a variable called cidr_suffix and set it to 24 to represent the number of bits used for the network part in CIDR notation.

Computer Networks

ip_addresses = {
    '192.168.1.0': '255.255.255.0',
    '10.0.0.0': '255.0.0.0',
    '172.16.0.0': '255.240.0.0'
}
# Add the cidr_suffix variable below
# Your code here

Need a hint?

Simply assign the number 24 to the variable cidr_suffix.

3

Create the CIDR notation dictionary

Create a new dictionary called cidr_notation that uses a for loop with variables ip and mask to iterate over ip_addresses.items(). For each IP, combine it with cidr_suffix to form a string like '192.168.1.0/24' and store it as the value in cidr_notation with the IP as the key.

Computer Networks

cidr_notation = {}
for ip, mask in ip_addresses.items():
    cidr_notation[ip] = f"{ip}/{cidr_suffix}"

Need a hint?

Use a for loop to build the new dictionary by combining the IP address and the CIDR suffix with a slash.

4

Add explanation entry to the dictionary

Add a new entry to the cidr_notation dictionary with the key 'explanation' and the value 'CIDR notation shows the IP address followed by a slash and the number of bits for the network part.'

Computer Networks

ip_addresses = {
    '192.168.1.0': '255.255.255.0',
    '10.0.0.0': '255.0.0.0',
    '172.16.0.0': '255.240.0.0'
}
cidr_suffix = 24
cidr_notation = {}
for ip, mask in ip_addresses.items():
    cidr_notation[ip] = f"{ip}/{cidr_suffix}"
# Add the explanation entry below
# Your code here

Need a hint?

Use the dictionary key assignment syntax to add the explanation string.