Cisco Certified Network Associate (CCNA) Day 3 - IP Addressing

Introduction

• Trainer: Imran Rafai
• Series: Free training series on YouTube
• Previous Video (Day 2): OSI Reference Model and TCP/IP Model
• Current Topic (Day 3): IP Version 4 (IPv4) Addresses
• Structure:
  • Day 3 (AM) - IP Address and Structures
  • Day 3 (PM) - Subnetting

Understanding IP Addresses

• Concept: IP addresses are not as difficult as they seem once basics are understood.
• Versions:
  • IPv4: Fourth version, widely used, connectionless protocol at Layer 3
  • IPv6: Newer, part of CCNA syllabus, addressed later

IP Address Basics

• Configuration Screens:
  • Windows and Mac users have different configurations
  • Commonly guided by administrators or colleagues
• Structure: Four octets separated by dots
• Key Components:
  • IP Address
  • Subnet Mask
  • Gateway (Router)
• Octet: Group of eight bits
• Binary to Decimal Conversion:
  • Use a table (1, 2, 4, 8, 16, 32, 64, 128)
  • Convert binary octets to decimal for human readability

IP Address Details

• Length: Four octets long (32-bits)
• Range: 0 to 255 per octet
• Invalid Address: If any octet > 255

Network and Host Concepts

• Subnet Mask: Decides network and host parts
  • Transition from 1s to 0s marks separation
• Examples:
  • Network: 192.168.100.0
  • Host: 192.168.100.255
• Analogy: Hotel address as network, room number as host
• Gateway: Must be in the same network for valid configuration

IP Address Classes

• Class A:
  • First Octet: 1-126
  • Subnet Mask: 255.0.0.0
  • Massive network, requires subnetting
• Class B:
  • First Octet: 128-191
  • Subnet Mask: 255.255.0.0
  • More manageable than Class A
• Class C:
  • First Octet: 192-223
  • Subnet Mask: 255.255.255.0
  • Smallest range
• Class D & E:
  • Class D for multicast
  • Class E reserved for experiments

Special Addresses

• Loopback Address: 127.x.x.x for internal testing

Subnetting

• Purpose: Divide large networks into smaller, manageable segments
• Ideal Network Size: Cisco recommends less than 500 hosts per network
• Subnetting Details: To be covered in Day 3 (PM)

Practical IP Address Examples

• Class B Example:
  • First Octet: 172
  • Subnet Mask: 255.255.0.0
  • Valid IP Range: 172.123.0.1 to 172.123.255.254
• Class A Example:
  • First Octet: 100
  • Subnet Mask: 255.0.0.0
  • Valid IP Range: 100.0.0.1 to 100.255.255.254

Testing Knowledge

• Practice Problems:
  • Evaluate IP address and gateway for validity
  • Example scenarios provided for application

Conclusion

• Encouragement: IP addresses are manageable with practice
• Feedback: Questions and comments encouraged in video comment section
• Engagement: Like, share, and subscribe to support the series

Closing

• Acknowledgment: Thank viewers and wish a Happy New Year
• Next Steps: Subnetting to be covered in the next video (Day 3 PM)