IPv4 – What is IPv4?

What is IP vs IPv4?

IPv4 is a short form of Internet Protocol version 4.  The 4th version of the Internet protocol (IP) is a widely used protocol that facilitates communication over the Internet.  It lays out the rules and constraints for communication over the Internet or within a local network.  Due to IP, we can have connected networks routing with packet forwarding as it specifies the format, the communications, IPv4 addresses, and routes data.

What is IPv4?

IPv4 is the core technology that allows us to connect our devices to the Internet.  When a device connects to the Internet, it is allocated a numerical IP address, like 99.48.227.227.  To transfer data through the web from one device to another, a data packet containing both devices’ IP addresses must be transmitted over the network.

An IPv4 address is expressed by four eight-bit binary numbers separated by a decimal point.  It can represent a distinct 32-bit number in any numbering system; however, IP addresses are most commonly represented in dot-decimal notation.

There are two types of IPv4 addressing:

• Classful

Addresses are classified according to five classes: Class A, B, C, D, and E. The Class A, B, and C addresses are all routable over the Internet.  Class D addresses are reserved for multicasting, and Class E addresses are reserved for experimental use.  Classful addressing is a legacy technology. Classful routing does not send subnet information in routing updates.  This means that all subnets are the same size and must have the same subnet mask.

• Classless

Addresses not artificially grouped based on classes, but rather a system known as Classless Inter-Domain Routing (CIDR) is applied.  Classless routing solutions include subnet information when exchanging routing updates.  This means that networks can be of different sizes to accurately reflect the number of hosts and networks needed without wasting space on unneeded IP addresses.  This system of varying the size of the network and subnet mask is known as Variable Length Subnet Mask (VLSM).  Modern routers use classless routing by default: routers do not think in terms of class when making routing decisions.

It is important to understand that modern network devices almost always use classless addressing because it enables much more efficient IP network address usage.  However, Class A, B, and C addresses encompass the space of Internet routable unicast IP addresses; the terms Class A, B, and C will still be used for easy reference.

Why do we need IPv4?

Whenever communications occur in a public medium, it is imperative to encrypt the data to safeguard privacy.  IPv4 employs security measures for encrypting data in its address packets.  Consequently, IPv4 maintains a higher level of privacy and security.  Also, all the systems can efficiently handle the IPv4 routing available in the IPv4 protocol.  Thus, the IPv4 protocol can be supported by nearly all major systems.

How does IPv4 work?

IPv4 operates on the network layer of the TCP/IP protocol stack.  The protocol’s fundamental purpose is to transfer data blocks from the sending host to the receiving host, where the sending and receiving hosts are both computers with unique IP addresses.

For a host to be able to communicate over the Internet with IPv4, it must be configured either manually or dynamically with:

•         An IP address
•         A subnet mask
•         A default gateway
•         Domain Name System (DNS) server address

DNS provides a mechanism for automating the associations between IP addresses with fully qualified domain names (FQDNs), such as server2.microsoft.com.  It is unreasonable to expect a human to remember the IP address for every website accessed.  If the website address is known, like server2.microsoft.com, DNS automatically converts the fully qualified domain name to an IP address that the computer or router can route the data.

What about enterprise usage of IPv4?

The IPv4 serves best when it comes to flexibility and scalability.  The routing on multiple ports is made more efficient and flexible.  In addition, reputable enterprises utilize IPv4, which facilitates data communications multicast.

Furthermore, IPv4’s primary function is to connect various devices across the extensive network. Along with the connection, identity verification can be performed for each device within the organization.  All of this can be accomplished without Network address translation (NAT).