IPv4

IP stands for Internet Protocol which is used to deliver datagrams between hosts in a network. Typically, it is a method by which data will be sent from one computer device to another computer device through the internet. IPv4 is the fourth version of the Internet Protocol that was adapted and is now widely used in data communication over different kinds of networks.[1] It is considered as one of the core protocols of standards-based internetworking methods on the internet and it was the first version that was deployed for production during the time of ARPANET. IP stands for a protocol that relies on packet-switched layer networks just like the Ethernet. It provides a logical connection between different network devices by providing identification for each device.

Functionality

IPv4 uses a 32-bit address scheme allowing a total of 2 to the power of 32 addresses or just over 4 billion addresses.[2] This is based on the best-effort model. The model makes sure that there is the avoidance of duplicate delivery. All these aspects are handled by the upper layer of transport. This version of IP is used as the basis of the internet, and it establishes all the rules and regulations for the computer networks that function on the principle of packet exchange. The responsibility of this protocol is to establish connections between computer devices, servers, and mobile devices that are based on IP addresses. In the exchange of information in IPv4, it is carried out by the IP packets. An IP packet is divided into 2 large fields, namely the header and the data field. The data field is used to carry important information while a header contains all the functions of the protocol.

IPv4 functions on the network layer of the TCP or IP protocol stack. Its main task is mainly to transfer the data blocks from the sending host to the destination host, where the senders and the receivers are computers that are uniquely identified by the Internet Protocol addresses. The good thing about the IP address is that it is used as a unique identifier for computing devices that are connected to a local network or the internet. It is typically used for addressing and transmitting data over the network. Without this, the device cannot determine where it is really transmitting data. All devices that are operating over a network, such as computer devices, network printers, telephones, servers and more really need their own network address.

The addresses of IP are somewhat similar to passport data. IPv4 addresses are, most of the time, written in a way with 4 decimal numbers starting from 0 up to 255 and separated by a period.

For example: 172.128.1.2

There is a minimum address and maximum address; the possible minimum address is 0.0.0.0 and the possible maximum address is 255.255.255.255. Without this IP address, a device will not be identified on the network or be capable to exchange information with other devices in the private network or in a public network.

Furthermore, this version of IP works at the network layer of the OSI model and at Internet layer of TCP or IP model. This gives the responsibility of IP to identify the host based upon the logical addresses and route the data between or among them over the underlying network. This IP which has a 3-layer protocol gets the data segments from the 4th layer which is transport and divides it into what is known as the packet. The IP packet encapsulates the data unit that is received from the above layer and it adds its own header information.[3]

Components

The following are the two parts of an IP address, based on the original design of IPv4:

Network identifier

This is a portion of IP address which is used to identify individuals or different devices on a network just like a local area network or the internet. This is design in order to make sure the security of a network and those related resources. This is the most significant octet of the address.

Host identifier

This refers to the name that is declared in the host program.

Addressing Modes

The following are the three different types of addressing modes supported by IPv4:

Unicast addressing mode

This address helps identify a unique node of a network. This simply refers to a single sender and a single receiver though it can be used in both sending and receiving. In this mode, the data will be sent only to one destined host. The destination address field has 32-bit IP address of the destination host. This is the most common form of addressing Internet Protocol.[4]

Broadcast addressing mode

This refers to a network address at which all devices that are connected to a multiple-access communication network are will be enabled to receive diagrams. A message that will be sent to a broadcast address may be received by all network-attached hosts. In this mode, the packet is addressed to all the hosts in a segment of a network. The destination address field has a special broadcast address. When the host will see a packet on the network, it is bound to process it.

Multicast addressing mode

In IPv4, this is defined by the most significant pattern of 1110. This includes the addresses from 224.0.0.0 to 239.255.255.255. This mode is a mix of the previous two modes. With this packet, the destination address contains a special address which starts from 224.x.x.x and can be entertained by more than one host. With the growth of the internet, it is really expected that the number of unused IPv4 addresses will eventually run out because every device like the computers, smartphones, and game consoles or those that connect to the internet will require an address.[5]

History

Current internet protocols incorporated into modern systems make use of more complex and intricate technologies that are based on developments made from the ARPANET’s (Advanced Research and Project Agency Network) NCP (Network Control Program) Protocol. Vinton Cerf and Robert Kahn are known as the forefathers of TCP/IP (Transmission Control Protocol / Internet Protocol).[6] Working with the TCP, IP was introduced as a datagram that did not rely on a connected protocol, but instead contained a header and a payload. The header encoded the source and destination addresses of the data packet while the payload carried the actual data. Cerf and Kahn worked with the US Department of Defense Agency in ping the first major version of the IP that is still currently widely used - IPv4.[7]

More specifically, IPv4 was first deployed in 1983 for the production in the ARPANET. IPv4 is described in IETF publication RFC 791 in 1981 replacing an earlier definition in 1980. However, the US government came to a realization that the IPv4 address presented a limited set of addresses, only around 4 billion possible combinations, for the 7 billion people in the world and started on a newer version that is now being integrated into existing networks - the IPv6.


  1. https://www.techopedia.com/definition/5367/internet-protocol-version-4-ipv4 ↩︎

  2. https://www.webopedia.com/DidYouKnow/Internet/ipv6_ipv4_difference.html ↩︎

  3. https://www.tutorialspoint.com/ipv4/ipv4_quick_guide.htm ↩︎

  4. https://www.techopedia.com/definition/2464/unicast-address ↩︎

  5. https://www.webopedia.com/DidYouKnow/Internet/ipv6_ipv4_difference.html ↩︎

  6. https://www.colocationamerica.com/blog/history-of-ip-address-part-2-tcp-ip ↩︎

  7. https://www.colocationamerica.com/ip-services/ipv4.htm ↩︎