Flashcards for IPv4 Subnetting Concepts

Class A - Range

10.0.0.0 to 10.255.255.255.

Class B - Range

172.16.0.0 to 172.31.255.255.

Class C - Range

192.168.1.0 to 192.168.1.255.

Subnet Mask - Purpose

Defines the network and host portions of an IP address.

Subnet Mask - Example

255.255.255.0 (first 24 bits are network

Number of Subnets Formula

2^n

Number of Hosts per Subnet Formula

2^m - 2

Why subtract 2 in the hosts formula?

To exclude the network and broadcast addresses.

Class C Network - Example

192.168.1.0/24.

Borrowing 2 Bits - Number of Subnets

2^2 = 4 subnets.

Borrowing 2 Bits - Number of Hosts per Subnet

2^(8-2) - 2 = 62 hosts per subnet.

Network Address

The first address in a subnet (e.g.

Broadcast Address

The last address in a subnet (e.g.

Usable Host Addresses

All addresses between the network and broadcast addresses.