Sub netting concept – Basic calculation

Sub netting concept can shortly represent as follows,
1). Calculate the number of subnets
Example:
192.168.0.1/27
In networking we can identify that there are IP classes as follows,
Class A: 1.0.0.0 -> 127.255.255.255 with a mask of /8 by default
Class B: 128.0.0.0 -> 191.255.255.255 with a mask of /16 by default
Class C: 192.0.0.0 -> 223.255.255.255 with a mask of /24 by default.
So we can identify y that the above IP address 192.168.0.1 is in class C. So by default, we have 24 bits for network part.
Here the /27 means we have 27 bits reserved for the network in the IP address. So here we applied 27 bits for this part. When we 27-23 the answer is 3. That means 3 bits used for subnet.
So here an extension of the default class C subnet mask with 3 bits results in the subnet mask as follows,

Network portion     Host portion

 
11111111.11111111.11111111.11100000
                 2⁷ 2⁶ 2⁵
11100000-> (128 x 1) + (64 x 1) + (32 x 1) + (16 x 0) + (8 x 0) + (4 x 0) + (2 x 0) + (1 x 0) = 224
Subnet mask is 255.255.255.224
Number of subnet will be 6. Because of 3 bits used in the subnet for the 2ⁿ-2 formula we assign 3 to the and subtract 2. Then answer is 6//
Calculate the subnets of the entire SL-Robotics network
192.168.50.x/27 ------------------à
11111111.11111111.11111111.11100000
Number of subnets     = 2⁵-2

    = 8-2

    =6//

 
2). Calculate number of hosts per subnet
Example:
192.168.0.1/27

We get to know that 3 bits used for subnet in this IP address. So in host portion that we can identify its final 0 is 2 ^5. So when we apply 2n-2 formula. It is 2⁵ -2, then the answer is 30.

Network portion     Host portion

 
11111111.11111111.11111111.11100000
                
2⁵
Calculate the number of hosts per subnet of the SL-Robotics network
192.168.50.x/27 ------------------à
11111111.11111111.11111111.11100000
Number of hosts per subnets        =2ⁿ-2

    =2⁵ -2

    =32-2

    =30//

Find default gateway address for each subnet
Example:
Here we take the host position part , then we are taking the values of each as follows,
111 000 000
128     64    32     
So here we are cutoff 1^st and last because there are not in use.

 

 

 

 
So we can identify that the default Gateway Address for each subnet as follows,

192.168.0.32

192.168.0.64

192.168.0.96

192.168.0.128

192.168.0.160

192.168.0.192

 
Identify default gateway address of SL-Robotic each subnet
111 000 000
128     64    32     
So here we are cutoff 1^st and last because there are not in use.

 

 

 

 

 
So the default gateway address for each subet,

192.168.50.32

192.168.50.64

192.168.50.96

192.168.50.128

192.168.50.160

192.168.50.192

Determine the range of each subnet and its loopback address
According to the example the subnetwork rage will be manage as follows,
Example:
Range of each subnet

Subnet1    :    192.168.0.33-192.168.0.62

Subnet2    :    192.168.0.65-192.168.0.94

Subnet3    :    192.168.0.97-192.168.0.126

Subnet4    :    192.168.0.129-192.168.0.158

Subnet5    :    192.168.0.161-192.168.0.190

Subnet6    :    192.168.0.193-192.168.0.222

 
Loopback address

• :192.168.0.63
• :192.168.0.95
• :192.168.0.127
• :192.168.0.159
• :192.168.0.191
• :192.168.0.223

Determine the range of each subnet and its loopback address of SL-Robotics
Range of each subnet

Subnet1    :    192.168.50.33-192.168.50.62

Subnet2    :    192.168.50.65-192.168.50.94

Subnet3    :    192.168.50.97-192.168.50.126

Subnet4    :    192.168.50.129-192.168.50.158

Subnet5    :    192.168.50.161-192.168.50.190

Subnet6    :    192.168.50.193-192.168.50.222

 
Loopback address

1. 192.168.50.63

2. 192.168.50.95

3. 192.168.50.127

4. 192.168.50.159

5. 192.168.50.191

7. 192.168.50.223