What are the types of IPv4 Addresses?

IPv4 supports various types of addressing modes to enable different communication patterns across networks. Understanding these addressing types is crucial for network design and implementation.

Unicast Addressing

A unicast address is assigned to a single network interface located on a specific subnet and facilitates one-to-one communication. This is a unique address worldwide for the identification of a machine on the network.

• Subnet prefix − The network identifier or network address portion of an IP unicast address. All nodes on the corresponding physical or logical subnet must share the same subnet prefix, which must be unique within the entire TCP/IP network.

• Host ID − The host address portion of an IP unicast address that identifies a specific network node to which computers are interfaced.

Multicast Addressing

A multicast address can be used for one or more network interfaces situated on multiple subnets. It enables one-to-many communication, delivering individual packets from one source to many destinations simultaneously. These addresses are elements of Class D addressing design.

Broadcast Addressing

A broadcast address is assigned to all network interfaces located on a subnet and is used for one-to-everyone communication on that subnet. It carries packets from one source to all interfaces on the subnet. Broadcast addresses can be categorized as network broadcast, subnet broadcast, all subnets directed broadcast, and limited broadcast.

IPv4 Address Classes

Internet addresses are classified into multiple classes based on the number of bits used for the network prefix and host ID. This classification determines the number of networks and hosts per network that each class can support.

Address Class Characteristics

• Class A − Uses an 8-bit network number whose first bit is always zero. Reserved for IP unicast addresses with large numbers of hosts. Uses only one octet to define network prefix. Can accommodate 128 networks with up to 16,777,214 hosts each.

• Class B − Facilitates 16 bits for the network address and 16 bits for the host address. The first two bits are continually 10. Used for medium to large-sized networks. Can support 16,384 networks with up to 65,534 hosts per network.

• Class C − Designed for small networks. The first 3 octets determine the network, and the last octet specifies host IDs. Can support up to 2,097,152 networks with up to 254 hosts per network. First three bits are continually set to 110.

• Class D − Defines IP multicast addresses ranging from 224.0.0.0 to 239.255.255.255.

• Class E − These addresses were reserved for experimental and future uses.

Comparison of Address Types

Conclusion

IPv4 addresses are categorized into unicast, multicast, and broadcast types for different communication patterns. The class-based addressing system (A, B, C, D, E) determines network size and host capacity, though modern networks primarily use classless addressing schemes.