IPv4 Address Classes, Hosts for Classes of IP Addresses And Network IDs and Broadcast Addresses

IPv4 Address Classes

Class D Addresses

•A Class D address begins with binary 1110 in the first 

octet.

•First octet range 224 to 239.

•Class D address can be used to represent a group of 

hosts called a host group, or multicast group.

Class E Addresses

•First octet of an IP address begins with 1111

•First octet range 240 to 255.

•Class E addresses are reserved for experimental 

purposes and should not be used for addressing hosts 

or multicast groups. 

Hosts for Classes of 

IP Addresses

Class A (24 bits for hosts) 224 - 2* = 16,777,214

 maximum hosts

Class B (16 bits for hosts) 216 - 2* = 65,534 

maximum hosts

Class C (8 bits for hosts) 28 - 2* = 254 maximum 

hosts

* Subtracting the network and broadcast reserved 

address

IP Addresses as Decimal 

Numbers

Network IDs and Broadcast 

Addresses

An IP address such as 176.10.0.0 that has all binary 

0s 

in the host bit positions is reserved for the network 

address.

An IP address such as 176.10.255.255 that has all

 binary 1s in the host bit positions is reserved for the

 broadcast address.