Redhat: Network IPs

Defining a Network

Three IP addresses are needed to define a network:

Network Address	The first Address of the network
Broadcast Address	The last address of the network
Subnet Mask	Defines the difference between two address

The range of IPs that can be used on a network are those between the network and broadcast addresses.

As an example a network defined with:

• Network Address = 192.168.122.0
• Subnet Mask = 255.255.255.0

The Broadcast Address is calculated as a logical or of the Network Address and Subnet:

Network = 11000000.10101000.01111010.00000000
Subnet = 11111111.11111111.11111111.00000000
~Subnet = 00000000.00000000.00000000.11111111
Logical or= 11000000.10101000.01111010.11111111
BroadCast = 192.168.122.255

This is a 24 Bit network as the subnet has 24 bits represented by 1's. It is sometimes shown using a different notation:

192.168.122.0/24