1. Master Subnetting – Section 3

2. What is Classful Subnetting
Subnet = Sub Divided Networks
Subnetting is the process of dividing a single network into multiple, equal length networks
Subnetting minimizes wasted address spaces
The term Classful address or subnet references that the address is now made up of three parts:
Network
Subnet
Host

3. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Knowing Binary Subnets & Prefix’s
Default Subnet mask differentiate the IP address into two parts
Network (Prefix)
Host

4. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Knowing Binary
Subnets & Prefix’s
Subnet mask subdivides the IP address into three parts when we discuss subnetting addresses
Network (Prefix)
Subnet (Prefix)
Host
The Prefix identifies the address that resides in the same subnet
The Host identifies the hosts belonging to that subnet
PREFIX : EQUAL IN ALL ADDRESSES IN THE SAME SUBNET HOST : DIFFERENT IN ALL ADDRESSES IN THE SAME SUBNET

5. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Knowing Binary Subnets
Define the size of the prefix (combine network and subnet) part of the addresses in a subnet
Define the size of the host part in the subnet
Can be used to calculate the number of hosts in a subnet
Can be used to calculate the number of subnets in the entire network
Can be used in binary calculations for subnet ID and Broadcast ID
When we talk about subnetting – we are simply changing 0’s from host, and turning them into 1’s for network/subnet

6. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Knowing Binary Binary Mask Logic
Logic
translates to 255 decimal
translates to 192 decimal
translates to 0 decimal
Decimal Mask
translates to 255 decimal
translates to 240 decimal
translates to 255 decimal
translates to 248 decimal
translates to 0 decimal

7. Knowing Binary
128 | 64 | 32 | 16 | 8 | 4 | 2 | 1

8. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Calculating Subnets
Calculate Existing Subnet Addresses:
P = Prefix | N = Network | S = Subnet | H = Host
STEPS:
Convert the mask to prefix format (P)
Determine (N) based on class
Calculate S = P – N
Calculate H = 32 – P
Calculate hosts/subnet: 2^H – 2
Calculate number of subnets: 2^S
BOOK EXAMPLES:

9. 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 Calculating Subnets
Calculate Existing Subnet Addresses:
P = Prefix | N = Network | S = Subnet | H = Host
STEPS:
Convert the mask to prefix format (P)
Determine (N) based on class
Calculate S = P – N
Calculate H = 32 – P
Calculate hosts/subnet: 2^H – 2
Calculate number of subnets: 2^S
BOOK EXAMPLES: