Subnetting | What Is A Subnet In Networking?

After learning the IP address and binary calculator, let’s move to subnetting. But, What is Subnet or Subnetting? Subnetting is logically dividing the network by extending the 1’s utilized in Subnet Mask. Subnetting lets you create a number of logical networks that exist inside a single class A, B, or C network. If you don’t subnet, you’re solely ready to make use of one network out of your class A, B, or C network. In other languages, subnetting is one network divided into completely different networks. Subnetting reduces the wastage of IP addresses. It will increase the variety of networks and reduces the variety of hosts. Hence, Subnetting explained.

CIDR: Classless Inter-Domain Routing (CIDR) is mainly the strategy that ISP’s (Internet service providers) use to allocate an address to an organization, a home-a buyer. They provide addresses in certain block sizes. It signifies the current of Network ID bits and it is usually denoted as a ‘/’.

How to search out CIDR values, for class A

/8                11111111.00000000.00000000.00000000                   255.0.0.0

/9                11111111.10000000.00000000.00000000                   255.128.0.0

/10              11111111.11000000.00000000.00000000                   255.192.0.0

/11              11111111.11100000.00000000.00000000                   255.224.0.0

/12              11111111.11110000.00000000.00000000                   255.240.0.0

/13              11111111.11111000.00000000.00000000                   255.248.0.0

/14              11111111.11111100.00000000.00000000                   255.252.0.0

15//             11111111.11111110.00000000.00000000                   255.254.0.0

/16              11111111.11111111.00000000.00000000                   255.255.0.0

For class B

/17              11111111.11111111.10000000.00000000                   255.255.128.0

/18              11111111.11111111.11000000.00000000                   255.255.192.0

/19              11111111.11111111.11100000.00000000                   255.255.224.0

/20              11111111.11111111.11110000.00000000                   255.255.240.0

/21              11111111.11111111.11111000.00000000                   255.255.248.0

/22              11111111.11111111.11111100.00000000                   255.255.252.0

/23              11111111.11111111.11111110.00000000                   255.255.254.0

/24              11111111.11111111.11111111.00000000                   255.255.255.0

For class C

/25              11111111.11111111.11111111.10000000                   255.255.255.128

/26              11111111.11111111.11111111.11000000                   255.255.255.192

/27              11111111.11111111.11111111.11100000                   255.255.255.224

/28              11111111.11111111.11111111.11110000                   255.255.255.240

/29              11111111.11111111.11111111.11111000                   255.255.255.248

/30              11111111.11111111.11111111.11111100                   255.255.255.252

We can’t use a /31 or /32 as a result of now we have not less than 2 host bit for assigning IP addresses to hosts.

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Subnetting Tutorials – What Is A Subnet

  1. How many subnets?
  2. How many valid hosts per subnet?
  3. What are the valid subnets ( block size)?
  4. What is the published address for every subnet?
  5. What are the valid hosts?

You need to be taught this desk:

27      26      25      24      23      22      21      20

128    64      32      16      8        4        2        1

Example of class C: 192.168.10.0/26

Note: change happens in the 4th octet.

Network address = 192.168.10.0

Subnet masks         = 255.255.255.192

We have to unravel all 5 questions mentioned above.

How many subnet:                   2n      n: number of network (on bit i.e. 1)

                                      22 = 4          (192 – 11000000 i.e. solely 2 on bits)

How many hosts per subnet:    2H-2           h: number of Host(off bit i.e.0)

                                                26-2 = 62    (11000000 i.e. 6 off bits)                  

What are the valid subnet:        256-192 = 64 . (we begin at zero and count in our block size, so subnets are 0, 64, 128, and 192.

What is the broadcast address for every subnet: the quantity proper earlier than the worth of the following subnet is all hosts bits turned on and equals the broadcast address. For the zero subnets the following subnet is 64, so the published deal for the zero subnets is 63. In a common broadcast address is the final host of the block, for zero to 64 blocks (i.e. one block) the final host is 63.

What are the valid hosts: there are the numbers between the subnet advert broadcast deal with. The best method to discover hosts is to put in writing our subnet address and the broadcast deal with. This means the valid hosts are apparent.


The subnets (do that first)
064128192

First valid host 
( perform this last)
165129193

Last valid host
62126190254

The broadcast address (do this second)
63127191255

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Example of class B: 172.16.0.0/20

Note: change happens in the 3rd octet.

Network address = 172.16.0.0

Subnet masks = 255.255.240.0

We have to solve all the 5 questions mentioned above.

How many subnets:                   2n      n: a variety of community (on bit i.e. 1)

                                      24 = 16        (240 – 11110000 i.e. solely Four on bits)

How many hosts per subnet:    2H-2           h: number of Hosts(off a bit i.e. 0)

                                                212-2 = 4094         (11110000.00000000 i.e. 12 off bits)                  

What are the valid subnet:        256-240 = 16. (we start at zero and count on our block size, so subnets are 0, 16, 32, 48, and many others. as much as 240. Notice that these are the identical numbers as a category C 240 masks, we simply put them within the third octet and add Zero and 255 within the fourth octet.

What is the broadcast address for every subnet:

What are the valid hosts:


The subnets (do that first)
0.016.032.048.0

First valid host( carry out this final)
0.116.132.148.1
Last valid host15.25431.25447.25463.254

The broadcast address
15.25531.25547.25563.255

Example of class A: 172.16.0.0/16

Note: change happens in the 2nd octet.

Network address = 10.0.0.0

Subnet masks = 255.255.0.0

We have to solve all the 5 questions mentioned above.

How many subnets:                   2n      n: number of networks (on bit i.e. 1)

                                      28 = 256      (255 – 11111111 i.e. all bits are on)

How many hosts per subnet:    2H-2            h: number of Host (off bit i.e.0)

                                                216-2 = 65,534(00000000.00000000 i.e. 12 off bits)              

What are the valid subnet:        256-255 =1. (all within the second octet. The subnets can be 10.0.0.0, 10.1.0.0, 10.3.0.Zero as much as 10.255.0.0

What is the broadcast address for every subnet:

What are the valid hosts:


The subnets (do that first) 

10.0.0.0

10.1.0.0

10.255.0.0 

First valid host

10.0.0.1

10.1.0.1

10.255.0.1 

Last valid host

10.0255.254 

10.1.255.254

10.255.254.255 

The broadcast address

10.0.255.255

10.1.255.255

10.255.255.255

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