IPv4 Addressing Overview and Classes

IPv4 Addressing Overview

• IPv4 addressing is managed by the Internet Assigned Numbers Authority (IANA).
• Current deployment of IPv4 addresses predominantly uses private IP addresses with Network Address Translation (NAT).

Class A Addresses

• Valid host range: 1.0.0.0 to 126.0.0.0 with a subnet mask of /8.
• Designed for large networks, accommodates a significant number of hosts.

Class B Addresses

• Valid host range: 128.0.0.0 to 191.255.0.0 with a subnet mask of /16.
• Identified by the two high-order bits, which are always set as 1 0.

Class C Addresses

• Valid host range: 192.0.0.0 to 223.255.255.0 with a subnet mask of /24.
• Characterized by the three high-order bits set to 1 1 0, suitable for smaller networks.

Class D Addresses

• Utilized for multicast communications, allowing data to be sent to multiple hosts simultaneously.
• Valid network range: 224.0.0.0 to 239.255.255.255, with four high-order bits set to 1 1 1 0.

Class E Addresses

• Reserved for experimental purposes and future developments.
• Valid network range: 240.0.0.0 to 255.255.255.255.

Private IP Address Ranges

• Class A private range: 10.0.0.0 to 10.255.255.255.
• Class B private range: 172.16.0.0 to 172.31.255.255.
• Class C private range: 192.168.0.0 to 192.168.255.255.