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

Welcome to Jeremy’s IT Lab

This video is an introduction to subnetting and the topics that will be covered in the series.

Introduction to Subnetting

• Subnetting is necessary for dividing networks into smaller subnetworks.

• The video series will cover subnetting for class C, class B, and class A networks.

Solving Subnetting Problems

This section provides clear steps for solving subnetting problems.

Steps for Solving Subnetting Problems

• Start with practice questions for class C networks.

• Review the solution to the previous quiz question from the last video.

• Discuss subnetting class B networks and explain that the process is the same as for other classes of addresses but can be more challenging with larger networks.

• Mention that class A networks will be covered in the next video.

Solving Quiz Question from Last Video

This section explains how to solve a specific subnetting problem from the previous video.

Solving Quiz Question: Dividing 192.168.1.0/24 Network into Four Subnets

• Determine that a /26 subnet is appropriate to accommodate 45 hosts per subnet.

• Assign block 192.168.1.0/26 to subnet 1 based on this calculation.

• Use the broadcast address of subnet 1 (192.168.1.63) as a hint to find the network address of subnet 2 (192.168.1.64).

• Repeat this process to find the network addresses and broadcast addresses of subnets 3 and 4.

Using Binary Representation

This section demonstrates how binary representation can help with understanding and calculating subnets.

Using Binary Representation

• Convert IP addresses into binary representation to analyze the network and host portions.

• Borrow bits from the host portion to expand the network portion and create subnets.

• Determine the broadcast address by setting all host bits to 1.

• Find the range of addresses for each subnet based on the network and broadcast addresses.

Subnetting Tricks

This section introduces a subnetting trick that can simplify finding network addresses.

Subnetting Trick: Adding 64

• Use a /26 subnet mask as an example with 6 host bits, allowing for 62 hosts per subnet.

• Add 64 to the last bit of the network portion to find the next subnet's network address.

• Repeat this process to find subsequent network addresses by adding 64 each time.

Dividing a Network into Five Subnets

This section presents another exercise on dividing a given network into five equal-sized subnets.

Dividing a Network into Five Subnets

• Given a /24 network (192.168.255.0/24), divide it into five subnets of equal size.

• The number of hosts per subnet is not specified in this case.

Timestamps are provided for each section, starting from when they appear in the transcript.

Subnetting with Borrowed Bits

In this section, the instructor explains how borrowing bits can be used to create subnets in a network.

Borrowing One Bit

• When one bit is borrowed, the network becomes a /25 network.

• Borrowing one bit allows for the creation of 2 subnets.

• The number of subnets can be calculated using the formula 2^X, where X is the number of borrowed bits.

Borrowing Two Bits

• Borrowing two bits allows for the creation of 4 subnets.

• However, if more than 5 subnets are needed, borrowing two bits is not sufficient.

Borrowing Three Bits

• Borrowing three bits allows for the creation of 8 subnets.

• In this case, there are more subnets than needed (5), but it demonstrates the concept.

Subnetting Example: Finding Network Address

This section provides an example of finding the network address when given an IP address and subnet mask.

• Given an IP address (192.168.5.57) and a /27 subnet mask.

• Convert the IP address to binary and show borrowed bits.

• Change all host bits to 0 to find the network address.

• Convert back to dotted decimal form to get the network address (192.168.5.32).

Subnetting Example: Finding Network Address - Practice

This section provides another example of finding the network address when given an IP address and subnet mask for practice.

• Given an IP address (192.168.29.219) and a /29 subnet mask.

• Convert the IP address to binary and show borrowed bits.

• Change all host bits to 0 to find the network address.

• Convert back to dotted decimal form to get the network address (192.168.29.216).

Subnetting Numbers and Class B Networks

This section discusses subnet sizes for class C networks and introduces subnetting with class B networks.

• Memorize the numbers for subnet sizes in class C networks.

• Each additional borrowed bit doubles the number of subnets.

• For host bits, each bit doubles the number of hosts, but subtract 2 for network and broadcast addresses.

• /31 allows only 2 addresses for point-to-point connections.

• /32 is used for specific host identification in routes and special cases.

Subnetting Class B Networks

This section explains that subnetting class B networks follows the same process as with class C networks.

• Class B networks have more host bits and therefore more possible subnets compared to class C networks.

• The process of subnetting remains the same.

• Examples with class B networks will be provided in subsequent sections.

New Section Subnetting a Network

In this section, the speaker explains how to subnet a network by borrowing bits and determining the appropriate prefix length. The process is demonstrated using examples with different numbers of subnets and hosts per subnet.

Subnetting a /16 Network

• To subnet a network, the 2 to the power of X formula is used, where X represents the number of borrowed bits.

• If no bits are borrowed, there is only one large /16 network.

• Borrowing one bit allows for 2 subnets (prefix length /17).

• Borrowing two bits allows for 4 subnets (prefix length /18).

• Borrowing three bits allows for 8 subnets (prefix length /19).

• Borrowing four bits allows for 16 subnets (prefix length /20).

• Borrowing five bits allows for 32 subnets (prefix length /21).

• Borrowing six bits allows for 64 subnets (prefix length /22).

• Borrowing seven bits gives us 128 subnets (prefix length /23), which meets the requirement of creating 80 subnets.

Example Subnetting Questions

Question 1: Dividing a Class B Network into 500 Subnets

• Given network: 172.22.0.0/16

• To create 500 subnets, borrow at least 9 bits (/25 prefix length).

Question 2: Creating Subnets with Equal Number of Hosts

• Given network: 172.18.0.0/16

• Required: Create 250 subnets with an equal number of hosts per subnet.

• Solution: Borrowing 8 bits (/24 prefix length) allows for 256 subnets and 254 hosts per subnet.

Identifying Subnet of a Host

• Given host: 172.25.217.192/21

• Convert the address to binary, change all host bits to 0, and convert back to dotted decimal.

• The subnet is 172.25.216.0/21.

Understanding Subnetting Patterns

• For each borrowed bit, the number of subnets doubles (2, 4, 8, 16, etc.).

• For each host bit, the number of addresses in each subnet doubles but subtracting 2 gives the usable host addresses.

• Memorizing these patterns is not necessary; understanding them helps in calculating subnets when needed.

New Section Subnetting Quiz Questions

The speaker presents five quiz questions related to subnetting concepts discussed in the video.

Question 1: Dividing a Network into Subnets with Specific Requirements

• Given network: 172.30.0.0/16

• Required: Create at least 100 subnets with a minimum of 500 hosts per subnet.

• Pause the video to find the answer.

Question 2: Identifying Subnet of a Host

• Given host: 172.21.111.201/20

• Pause the video to find the answer.

Question 3 and Beyond

The remaining quiz questions are not provided in this transcript.

Please refer to the video for answers and explanations to these quiz questions.

How Many Subnets Can You Make?

In this section, the speaker discusses subnetting a network and determining the number of subnets that can be created.

Determining Number of Subnets

• To determine the number of subnets that can be created from a given network, you need to divide the network into smaller subnets.

• In this example, the speaker divides the 172.30.0.0/16 network into subnets with 1000 hosts each.

• The question is posed: How many subnets are you able to make?

• Pause the video to find the answer.

Practice Lab Coming Soon

The speaker provides information about upcoming practice labs and thanks channel members for their support.

Practice Lab Announcement

• After the next video, a practice lab will be provided where you can subnet a network and assign IP addresses to devices in each subnet.

• Viewers are encouraged to wait for this practice lab opportunity.

Shoutout to Channel Members

• The speaker gives a shoutout to JCNP-level channel members Vance, Mike Yonatan, and Lito for their support.

• Thanks are also extended to all JCNA-level members.

Support Options

The speaker shares different ways viewers can show support for the channel and make donations.

Donation Options

• Viewers have multiple options for making donations:

• Cryptocurrency donations are accepted via links in the video description.

• Patreon donations are accepted via links in the video description.

• BAT (Basic Attention Token) tips can be given through Brave browser, which is described as a fast and sleek browser that pays users to surf the Internet.

Summary

In this video transcript summary:

• The speaker discusses subnetting a network and determining the number of subnets that can be created.

• An upcoming practice lab is announced where viewers can practice subnetting and assigning IP addresses to devices in each subnet.

• Channel members are thanked for their support, and different donation options are provided for viewers who want to show support.