Free CCNA | Subnetting (Part 1) | Day 13 | CCNA 200-301 Complete Course

Introduction

This tutorial introduces subnetting, focusing specifically on Class C networks as part of the CCNA 200-301 course. Understanding subnetting is essential for network management and design, enabling you to efficiently allocate IP addresses within a network.

Step 1: Understand IPv4 Address Classes

• IPv4 Address Classes: Familiarize yourself with the different classes of IPv4 addresses:
  • Class A: 1.0.0.0 to 126.0.0.0
  • Class B: 128.0.0.0 to 191.255.255.255
  • Class C: 192.0.0.0 to 223.255.255.255
• Usage: Class C is commonly used for small networks, providing up to 254 usable addresses.

Step 2: Learn About IPv4 Address Assignment

• Public vs. Private Addresses: Understand the difference between public IP addresses (accessible over the Internet) and private IP addresses (used within local networks).
• Private Address Ranges for Class C:
  • 192.168.0.0 to 192.168.255.255 is reserved for private use.

Step 3: Explore CIDR Notation

• CIDR Definition: Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and IP routing.
• CIDR Notation: Learn how to express network prefixes, for example, a subnet mask of 255.255.255.0 is represented as /24 in CIDR.

Step 4: Calculate Usable Addresses per Subnet

• Subnetting Basics: Know that each subnet has a certain number of usable addresses based on the subnet mask.
• Formula: Use the formula (2^n) - 2, where n is the number of bits available for hosts.
  • Example for a /24 subnet:
    • 2^(32-24) - 2 = 254 usable addresses.

Step 5: Understand Special CIDR Cases

• CIDR /31: This CIDR notation allows for two addresses, primarily used for point-to-point links. Both addresses can be assigned to devices in this scenario.
• CIDR /32: Represents a single host address, often used for routing and management purposes.

Step 6: Apply Subnetting to Scenarios

• Subnetting Scenario: Practice subnetting by dividing a Class C network into smaller subnets.
  • Determine how many subnets and usable addresses you need based on the requirements of your network design.

Step 7: Test Your Knowledge

• Quiz Yourself: After learning the concepts, take a quiz to test your understanding of subnetting and CIDR. This reinforces your knowledge and identifies areas for improvement.

Conclusion

Subnetting is a crucial skill in networking that allows for efficient IP address management. By understanding the classes of IPv4 addresses, CIDR notation, and calculating usable addresses, you can design and manage networks more effectively. Consider practicing subnetting scenarios and utilizing flashcards for review. For additional resources, check out the free CCNA flashcards and labs linked in the video description.