Thread by @devops_tech

Mastering Subnetting from scratch!

A thread with examples 👇

1/10: Subnetting is the process of dividing a network into smaller subnetworks, called subnets. It allows efficient use of IP addresses and helps manage network resources effectively. #Subnetting101

2/10: To subnet, you need to understand IP addresses, specifically IPv4. An IPv4 address consists of four octets (or bytes), separated by periods. Each octet ranges from 0 to 255. For example, 192.168.0.1 is an IPv4 address. #IPv4Basics

3/10: Subnetting is based on a concept called the subnet mask. The subnet mask determines the network portion and the host portion of an IP address. It is represented using the same format as an IP address, using binary or slash notation. #SubnetMaskBasics

4/10: In binary, the subnet mask consists of 1s for the network portion and 0s for the host portion. For example, a subnet mask of 255.255.255.0 in binary is 11111111.11111111.11111111.00000000, or /24 in slash notation. #BinaryNotation

5/10: To subnet, you borrow bits from the host portion of the IP address and use them to create subnets. The number of borrowed bits determines the number of subnets you can create. #BorrowingBits

6/10: Let's say you have an IP address range 192.168.0.0/24 and you want to create 4 subnets. To do this, you need to borrow 2 bits from the host portion since 2^2 = 4. #Example

7/10: Borrowing 2 bits gives us 6 usable subnets:

192.168.0.0/26, 192.168.0.64/26, 192.168.0.128/26, 192.168.0.192/26, and two more subnets that follow.

The /26 represents the number of network bits. #UsableSubnets

8/10: The subnet mask for the /26 subnets is 255.255.255.192 in decimal or 11111111.11111111.11111111.11000000 in binary. This means we have 6 subnets, each with 62 usable host addresses (2^6 - 2). #SubnetMask

9/10: To determine the network address, you take the original network address and increment it based on the number of subnets. For example, 192.168.0.0 is the first network, then 192.168.0.64, 192.168.0.128, and so on. #NetworkAddresses

10/10: Subnetting allows for efficient allocation of IP addresses and better network management. It's an essential skill for network administrators. Remember, practice makes perfect! #NetworkingSkills #SubnettingMadeEasy

Here's an another example where we create six small networks out of a big /24 network 👇

1/8: Let's explore an example of subnetting a big /24 network into six smaller networks. We have the IP address range 192.168.0.0/24 and we want to create six subnets with equal-sized address ranges. #SubnettingExample

2/8: To create six subnets, we need to borrow 3 bits from the host portion of the IP address. This gives us 14 usable subnets. Each subnet will have 30 usable host addresses. #BorrowingBits

3/8: The subnet mask for the new subnets will be 255.255.255.224 or /27 in slash notation. This means the first two octets (192.168) remain the same, and the last octet will be divided into network and host portions. #SubnetMask

4/8: Let's assign the network addresses for the six subnets. The first subnet will be 192.168.0.0/27, the second will be 192.168.0.32/27, the third will be 192.168.0.64/27, and so on. #NetworkAddresses

5/8: Each subnet has 30 usable host addresses. Remember, we subtract 2 from the total (2^5) to account for the network address and the broadcast address. These addresses cannot be assigned to hosts. #UsableHostAddresses

6/8: So, for example, the first subnet (192.168.0.0/27) will have usable host addresses from 192.168.0.1 to 192.168.0.30. The second subnet will have addresses from 192.168.0.33 to 192.168.0.62, and so on. #UsableHostAddresses

7/8: With six smaller subnets, we can efficiently allocate IP addresses and manage our network resources. Subnetting helps optimize network utilization and facilitates better organization. #EfficientNetworking #SubnettingExample

8/8: Subnetting is a valuable skill for network administrators, enabling effective management of IP addresses and network resources. Practice subnetting to strengthen your networking expertise. #NetworkingSkills #SubnettingMadeEasy

I hope this example demonstrates how to subnet a big /24 network into six smaller networks. If you have any further questions or need more clarification, feel free to ask!

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