Jeremy's IT Lab - CCNA Lecture 8: IPv4 Addresses Part 2

Introduction

• This lecture is part of a free complete course for the CCNA.
• Focuses on IPv4 addresses, specifically calculating maximum hosts, network and broadcast addresses, and configuring Cisco devices.

IPv4 Address Classes

• Class A:
  • Usable range 1-126 (0 and 127 are reserved).
  • Network number bit field size is 8. Host portion is 24 bits.
• Class B:
  • Network number bit field size is 16. Host portion is 16 bits.
• Class C:
  • Network number bit field size is 24. Host portion is 8 bits.

Calculating Maximum Number of Usable Addresses

• Formula: 2^N - 2 (N = number of host bits).
• Example Calculations:
  • Class C (192.168.1.0/24): Maximum hosts = 256 - 2 = 254.
  • Class B (172.16.0.0/16): Maximum hosts = 65,536 - 2 = 65,534.
  • Class A (10.0.0.0/8): Maximum hosts = 16,777,216 - 2 = 16,777,214.

Finding First and Last Usable Addresses

• Class C Example (192.168.1.0/24):
  • First usable: 192.168.1.1
  • Last usable: 192.168.1.254
• Class B Example (172.16.0.0/16):
  • First usable: 172.16.0.1
  • Last usable: 172.16.255.254
• Class A Example (10.0.0.0/8):
  • First usable: 10.0.0.1
  • Last usable: 10.255.255.254

Configuring IP Addresses on Cisco Devices

• Network Setup:
  • Class A: 10.0.0.0/8
  • Class B: 172.16.0.0/16
  • Class C: 192.168.0.0/24
• Command Line Interface (CLI) Commands:
  • show ip interface brief: Displays IP addresses and status of interfaces.
  • configure terminal or conf t: Enter global config mode.
  • Interface configuration: Use interface gigabitethernet commands.
  • Assign IP address with ip address [IP] [subnet mask].
  • Enable interface with no shutdown.

Additional CLI Commands

• show interfaces: Displays detailed Layer 1 and 2 information.
• show interfaces description: Shows interface statuses and optional descriptions.

Quiz Recap

• Various IP addresses are given, and students calculate:
  • Network address
  • Maximum number of hosts
  • Broadcast address
  • First and last usable addresses

Resources and Tips

• Download Anki flashcards for practice.
• Try out the practice lab using Packet Tracer.
• Engage with the community by subscribing, commenting, and sharing videos.

Conclusion

• This lecture focused on deepening understanding of IPv4 addresses and practical configuration on Cisco devices.
• Further practice materials are provided for better retention and application of the knowledge gained.