IP Subnetting

Subnet Mask
* Subnet Mask differentiate the Network and Host portions of an IP address.
* Represented with all 1`s in the network portion and with all0`s in the host portion.
Example of subnet mask
* Class A : N.H.H.H
11111111.00000000.00000000.00000000
Default subnet mask for class A is 255.0.0.0
* Class B : N.N.H.H
11111111.11111111.00000000.00000000
Default subnet mask for class B is 255.255.0.0
* Class C : N.N.N.H
11111111.11111111.11111111.00000000
Default subnet mask for class C is 255.255.255.0

How Subnet Mask Works?
IP Address    :    192.168.1.1
Subnet Mask:    255.255.255.0
ANDING PROCESS:
192.168.1.1    =11000000.10101000.00000001.00000001
255.255.255.0=11111111.11111111.11111111.00000000
---------------------------------------------------------------
192.168.1.0    =11000000.10101000.00000001.00000000
---------------------------------------------------------------
The output of an AND table is 1 if both its input are 1
for all other possible inputs the output is 0.

SUBNETTING
Dividing the large network into small sub network is called subnetting. the main purpose of using subneting is to utilize the IP address, and save the IP address. By converting host bit into network bit is called subneting.
* Creating Multiple independent Network from a Single Network.
* Converting Host Bits into Network Nits.
    i.e. Converting 0`s into 1`s
* It is also know as FLSM (fixed Length Subnet Mask)
* Efficiently utilize the IP address
* Subnetting Can be Performed in two way:
    => FLSM (fixed Length Subnet Mask)
    => VLSM (Variabe Length Subnet Mask)
* Subnetting can be done based on requirement
    => Number of Networks required?
    => Number of Hosts required?
Example of Subnetting :
QUE:1. Requirement of Network is 2?
ANS: 
Class C : N.N.N.H
Class C 192.168.1.0
No. of subnet
     = 2ⁿ-2 > Req. of subnet
     = 2²-2 > 2 (-2 is for First & Subnet Range)
     = 4-2
     = 2 Subnet
No. of Host
     = 2^h-2 (-2 is for Network ID & Broadcast ID)
     = 2⁶-2
     = 64-2
     = 62 Host/Subnet
Customized subnet mask
255.255.255.192
Host Range
192.168.1.64 to 192.168.1.127
192.168.1.128 to 192.168.1.191

QUE:2. Requirement of Host is 40?
ANS: 
Class C : N.N.N.H
Class C 192.168.1.0
No. of Host
     = 2^h-2 > Req. of Host
     = 2⁶-2 > 40 (-2 is for Network ID & Broadcast ID)
     = 64-2
     = 62 Host/Subnet
No. of Subnet
     = 2ⁿ-2 (-2 is for First & Subnet Range)
     = 2²-2
     = 4-2
     = 2 Subnet
Customized subnet mask
255.255.255.192
Host Range
192.168.1.64 to 192.168.1.127
192.168.1.128 to 192.168.1.191