SUBNETEO DE REDES [CAPITULO V] {Subneteando una red Clase B}

Summary

In this tutorial, Eliéser De León walks viewers through the process of subnetting a Class B IP address. He explains the steps of dividing the IP, including identifying the subnet mask, calculating the required number of subnets, adjusting the mask, and determining usable hosts per subnet. With a practical example, Eliéser demonstrates how to calculate subnets, set the new subnet mask, and determine usable IP addresses. Ideal for network enthusiasts, this video provides a clear and straightforward guide to subnetting a Class B IP address.

Takeaways

• 😀 Understand that the video covers subnetting of a Class B IP address (132.18.0.0/16).
• 😀 The importance of reviewing previous chapters (like Chapter 3) to understand the steps of subnetting is emphasized.
• 😀 The process starts by identifying the given IP and understanding its Class B classification based on the /16 prefix.
• 😀 The first step is to determine the number of required subnets and calculate the appropriate exponent (n) using the formula 2^n ≥ required subnets.
• 😀 For the given example, the formula 2^6 = 64 is used to create at least 50 subnets.
• 😀 After calculating the number of subnets, bits from the host portion of the IP address are borrowed to meet the subnet requirements.
• 😀 The new subnet mask is then calculated by changing the host portion bits and converting it back to decimal format.
• 😀 The number of hosts per subnet is determined using the formula 2^m - 2, where m represents the number of available host bits.
• 😀 The formula for calculating the 'network jump' (or the increment) between subnets is also discussed, which in this case is 4.
• 😀 The process for filling out the subnet table involves calculating the first and last usable IP addresses, along with the broadcast address for each subnet.
• 😀 Although space limitations prevent showing all 50 subnets in the video, a spreadsheet is provided to demonstrate the full range of subnets.

Q & A

What is the purpose of the video tutorial?

The purpose of the video is to teach viewers how to subnet a Class B IP address, specifically splitting it into 50 subnets with a minimum of 1,000 hosts per subnet.

Why is the prefix /16 used in the example?

The prefix /16 means that the first 16 bits of the IP address are used for the network portion, which is typical for Class B addresses. It leaves the remaining 16 bits for hosts.

What is the significance of the formula '2^n' in subnetting?

'2^n' is used to calculate the number of subnets that can be created by borrowing bits from the host portion of the IP address. 'n' is the number of bits borrowed.

How do you calculate the number of subnets needed?

To calculate the number of subnets, you use the formula '2^n ≥ number of subnets'. For example, to create 50 subnets, 2^6 = 64, which is sufficient since 64 is greater than 50.

How do you determine the new subnet mask?

The new subnet mask is determined by borrowing bits from the host portion of the IP address. In this example, borrowing 6 bits from the host part changes the subnet mask from /16 to /22, which corresponds to 255.255.252.0.

What is the formula for calculating the number of hosts per subnet?

The formula for calculating hosts per subnet is '2^m - 2', where 'm' is the number of remaining bits in the host portion. For example, with 10 remaining bits, the number of hosts is 2^10 - 2 = 1,022 hosts per subnet.

How is the subnet increment calculated?

The subnet increment is calculated by subtracting the altered octet value from 256. In this case, with the subnet mask of 255.255.252.0, the increment is 256 - 252 = 4, meaning each subnet will increment by 4 in the third octet.

How do you calculate the usable IPs and broadcast address for each subnet?

The usable IPs for each subnet are the range between the network address and the broadcast address. For example, the first subnet (132.18.0.0/22) has usable IPs from 132.18.0.1 to 132.18.3.254, with the broadcast address being 132.18.3.255.

Why can’t all 50 subnets be shown on the whiteboard during the video?

The instructor mentions that due to space limitations on the whiteboard, only the first 8 subnets are shown. However, viewers are told that all 50 subnets can be seen in an image of the completed table shared at the end.

How can viewers complete the subnetting table if they cannot see all 50 subnets in the video?

Viewers are encouraged to use a spreadsheet program to complete the table for all 50 subnets by following the same steps demonstrated in the video for the first few subnets. The instructor provides the full table at the end for reference.