Free CCNA | Subnetting (Part 2) | Day 14 | CCNA 200-301 Complete Course

TL;DR

This video provides a step-by-step guide on how to subnet Class C and Class B networks, with examples and practice questions.

Transcript

Welcome to Jeremy’s IT Lab. This is a free, complete course for the CCNA. If you like these videos, please subscribe to follow along with the series. Also, please like and leave a comment, and share the video to help spread this free series of videos. Thanks for your help. In this video, we’ll continue to learn about subnetting. Last video I introd... Read More

Key Insights

• 💻 Subnetting is an important topic in CCNA and can be applied to Class C, Class B, and Class A networks. It involves dividing a network into smaller subnets to accommodate different numbers of hosts.
• 💡 When subnetting a Class C network, finding the broadcast address of one subnet can help determine the network address of the next subnet. This can be done by setting all the bits in the host portion to 1.
• 💡 The process of subnetting is the same for Class B networks as it is for Class C networks. However, with Class B networks, there are more host bits and therefore more possible subnets that can be created.
• 💡 To determine the subnet a host belongs to, convert the host's IP address to binary, change all the host bits to 0, and then convert it back to dotted decimal.
• 📊 For Class C networks, here are some available subnet sizes: /25 allows for 2 subnets with 126 hosts each, /26 allows for 4 subnets with 62 hosts each, and /27 allows for 8 subnets with 30 hosts each.
• 📊 For Class B networks, the number of available subnets and host addresses follows a similar pattern as Class C networks. Borrowing additional bits doubles the number of subnets, while adding additional host bits doubles the number of host addresses (subtracting 2 for the network and broadcast addresses).
• ✅ In the quiz, participants are tested on their ability to subnet Class B and Class C networks, identify network and broadcast addresses, and determine the subnet a host belongs to. The answers and explanations will be provided in the next video.
• ❗️ It is important to note that while these calculations can help determine appropriate subnet sizes, they may not always align exactly with the required number of subnets or hosts.

Questions & Answers

Q: What is the difference between subnetting Class C and Class B networks?

The main difference between subnetting Class C and Class B networks is the number of host bits and the range of possible subnets. Class C networks have fewer host bits and a smaller range of subnets compared to Class B networks.

Q: How can you determine the network and broadcast addresses of a subnet?

To determine the network address of a subnet, you need to change all the host bits to 0 in the subnet's IP address. The broadcast address can be found by changing all the host bits to 1.

Q: How many subnets can be created with a /18 prefix length in a Class B network?

With a /18 prefix length in a Class B network, 4 subnets can be created.

Q: How many host addresses are available in each subnet with a /25 prefix length in a Class B network?

With a /25 prefix length in a Class B network, there are 126 host addresses available in each subnet (2^7 - 2).

Q: Can you use a /31 prefix length in a subnet?

Yes, a /31 prefix length can be used for point-to-point connections, where only two host addresses are required.

Summary & Key Takeaways

• The video introduces the concept of subnetting and why it is necessary.

• It provides clear steps and examples for solving subnetting problems in Class C and Class B networks.

• The video also covers how to determine the network and broadcast addresses of subnets.