IPv4 and IPv6

What is IPv4

IPv4 is an acronym for Internet Protocol Version 4 which denotes the fourth generation of Internet protocol (IPv4). An Internet Protocol (IP) is a unique identifier used to differentiate devices connected to a network. Initially deployed for the purpose of powering the ARPANET in 1983, this version of IP routes most of the internet traffic.

IPv4 is numerically represented by 32-bit numerical values, which are further divided into 4 octets. Each octet has 8 bits and each bit value can be calculated using the position of value bit ‘1’ contained in the octet.

However, the 4.3 billion IP addresses that are supported by IPv4 are almost exhausted, hence the transition to IPv6 has been on roll over the past few years.

The global allocation and management of IPv4 are conducted by the Internet Assigned Numbers Authority (IANA) with help from other entities such as Internet Corporation for Assigned Names and Numbers (ICANN).

IPv4 Packet Structure

Ip exists in the 3rd layer of the OSI model and therefore plays a critical role in dividing segments into packets. The Internet Protocol (IP) encapsulates data units from the initial layers and embeds them into its header information. The encapsulated data is called the IP payload. The IP header has all the information needed for secure packet delivery.

Some information found in the header includes identification, header version, protocol, header checksum, a destination address, and other relevant information.

IPv4 Addressing

IPv4 supports the three addressing types; Unicast, Broadcast, and Multicast. As the name suggests, data in the Unicast mode is sent only to one host. Unlike The Unicast mode, the Multicast supports packet delivery to all hosts existing in a network. The multicast mode is a combination between the Unicast and Broadcast, and packets neither belong to a single host nor all hosts existing in a segment.

IPv4 Key Characteristics

• 32 Bit (4 bytes) destination and Source addresses
• IP header has Checksum
• Utilization of broadcast when forwarding traffic to all nodes in a subnet
• Internet Group Management Protocol (IGMP) is used in the management of subnet group membership
• Options are available in the IP header
• Source hosts and intermediate routers have fragmentation privileges
• Support for integrated and differentiated services in Quality of Service (QoS)

What is IPv6

Developed by the Internet Engineering Task Force (IETF) to combat the fast exhaustion of IPv4 addresses, Internet Protocol Version 6 (IPv6) is the latest version of IP that is used for the identification of networks and devices across the internet. It is also responsible for traffic routing.

Unlike IPv4, IPv6 works by assigning unique IP addresses to devices for the purpose of location and identification. While Ipv4 supports approximately 4.3 billion devices, IPv6 utilizes a 128-bit addressing system that can support up to 2 ^ 128 (340 trillion).

The structure of IPv6 is represented as 8 groups of 4 hexadecimal digits separated by colons. An example of Ipv6 is 1001:cd7::7e2a:250:8454.

IPv6 features

Ipv6 provides end-to-end datagram transition to several networks by using its multicasting capabilities and also supports packet-switched networking. IPv6 eases the transition journey from IPv4 by following the core design principles used in the development of IPv4.

Apart from providing more addresses, IPv6 integrates other functionality such as simplification of address configuration, ease of packet processing, network renumbering, and many other features. It supports Unicast, Multicast, and anycast transmissions.

IPv6 Packets, Addressing, and Security

The IPv6 packet is made up of a header and a payload. The fixed header, occupying 320 bits of the packet, contains critical information such as optical extension type, source and destination address, a hop counter, and classification options. The next header contains interpretation instructions for the following header. Extension headers are responsible for carrying components needed for the special treatment of packets including security, fragmentation, and routing.

IPv6 addresses are made up of 128 bits and use subnetting to increase functionality through efficient address space utilization. For security, IPv6 uses integrated security mechanisms such as packet fragmentation and the utilization of shadow networks.

Why IPv6?

There are many advantages in using IPv6 including:

• Network configuration is simplified through in-built address auto-configuration.
• Support for new features and services such as easy peer-to-peer network creation and maintenance.
• IPv6 offers in-built data integrity, authentication, and confidentiality through the integration of defense mechanisms such as ICMPv6.
• IPv6 Offers efficient packet processing capabilities.
• Directed data flows through the use of multicast as opposed to broadcast addressing.