Jeremy’s IT Lab - CCNA Course: Subnetting Series (Final Video)

Introduction

• Course Overview: Complete CCNA course, free on Jeremy’s IT Lab.
• Video Focus: Final video on subnetting - crucial topic for CCNA.

Video Content

1. Review of Last Video's Quiz
2. Practice Questions with Class A Addresses
3. VLSM (Variable-Length Subnet Masks)
4. Additional Subnetting Resources

Quiz Review

Question 1

• Given Network: 172.30.0.0/16
• Requirement: 100 subnets, at least 500 hosts per subnet.
• Solution:
  • Borrow 7 bits → 128 subnets
  • Use /23 prefix length → 510 usable host addresses
  • Answer: /23 or 255.255.254.0

Question 2

• Host: 172.21.111.201/20
• Solution:
  • Convert to binary, change host bits to 0.
  • Answer: Subnet 172.21.96.0/20

Question 3

• Network: 192.168.91.78/26
• Solution:
  • Change host bits to 1 for broadcast address.
  • Answer: 192.168.91.127

Question 4

• Network: 172.16.0.0/16 divided into 4 equal subnets.
• Solution:
  • Borrow 2 bits → /18 prefix length
  • Answer: Second subnet network: 172.16.64.0, broadcast: 172.16.127.255

Question 5

• Network: 172.30.0.0/16 into subnets with 1000 hosts each.
• Solution:
  • Need 10 host bits → 6 bits for subnets
  • Answer: 64 subnets

Subnetting Class A Networks

• Example: 10.0.0.0/8 network for 2000 subnets

  • Solution:
    • Borrow 11 bits → Use /19 prefix
    • Hosts per Subnet: 8190 hosts

• Exercise: PC1 with IP 10.217.182.223/11

  • Find: Network, Broadcast, First and Last Usable, Host Addresses
  • Solution:
    • Network Address: 10.192.0.0
    • Broadcast Address: 10.223.255.255
    • First Usable: 10.192.0.1
    • Last Usable: Derived from Broadcast
    • Host Addresses: 2,097,150

VLSM (Variable-Length Subnet Masks)

• Comparison: VLSM vs. FLSM (Fixed-Length Subnet Masks)
• Advantage: Efficient use of IP address space
• Process:
  1. Assign largest subnet first
  2. Continue in descending order of size

Example Scenario

• Network: 192.168.1.0/24 divided into 5 subnets
• Subnets:
  • Tokyo LAN A: 110 hosts, /25 prefix
  • Toronto LAN B: 45 hosts, /26 prefix
  • Toronto LAN A: 29 hosts, /27 prefix
  • Tokyo LAN B: 8 hosts, /28 prefix
  • Point-to-Point: 2 hosts, /30 prefix

Practice and Resources

• Websites for Practice:
  • subnettingquestions.com
  • subnetting.org
  • subnettingpractice.com
• Homework: Practice one question daily from each site for a week.

Conclusion

• Thank Yous: Shoutouts to channel members.
• Call to Action: Like, subscribe, comment, share, and tips via links.

This summary captures the essential points from the subnetting lecture in Jeremy’s IT Lab series, aiding in the understanding and review of subnetting concepts including class A network addressing and VLSM.