Course: Cloud Computing Module: Networking for Cloud Computing Date: 1st July, 2026

Learning Objectives

By the end of this lesson, I was able to:

• Explain CIDR notation
• Convert CIDR prefixes to subnet masks
• Determine subnet increments (Magic Numbers)
• Identify subnet boundaries
• Determine the Network ID
• Determine the Broadcast Address
• Identify the First and Last Valid Host
• Identify the subnet an IP address belongs to
• Solve subnetting problems without using an online calculator

Key Concepts Learned

CIDR Notation

CIDR specifies how many bits belong to the network portion of an IPv4 address.

Example:

192.168.10.0/24
Network Bits = 24
Host Bits = 8
Total Addresses = 256

Note: "Total Addresses" (256) includes the Network ID and Broadcast Address, which cannot be assigned to hosts. Total Usable Hosts = Total Addresses − 2. For a /24, that's 254 usable hosts.

Subnet Mask Reference