An endpoint device in an IPv6 network is identified by an IPv6 address, which is a 128-bit alphanumeric value. The IPv6 addressing infrastructure replaces the IPv4 addressing infrastructure, which had constraints that IPv6 was created to address.

In this article, we will look more into the IPv6 Address according to the GATE Syllabus for (Computer Science Engineering) CSE. We will read ahead to find out more about it.

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What is an IPv6 Address?

IPv6 addresses are 128-bit alphanumeric values that identify endpoint devices in IPv6 networks. As a result of the IPv6 addressing infrastructure replacing IPv4’s infrastructure, IPv6 has several advantages over IPv4. IPv6 has significantly more address space than IPv4 does.

Data is transmitted to many computers via the internet using the Internet Protocol (IP). There will be at least one IP address assigned to each network interface or computer on the internet, which is used to identify that computer uniquely. An IP address is given to each computer or other device that connects to the internet. Because of this, the IETF developed the new IPv6 standard in response to concerns over the IP address capacity of IPv4.

IPv6 is supported by operating systems (OSes) such as Windows 10, macOS, and Ubuntu. Presently, different address types are used. As of now, devices use IPv6 or IPv4. Since 2008, domain name systems have supported IPv6.

The IPv4 addressing scheme’s possible address shortage has been a problem for a while. The IPv6 standard was developed to allow trillions of additional IP addresses to connect an increasing number of computer devices and an increasing number of objects with embedded connectivity. Over 340 undecillion (340 trillion trillion trillion) IPv6 addresses could potentially exist, according to calculations. Dick Guertin, a docent at the Computer History Museum, claims that the amount enables an IPv6 address for each atom on the planet’s surface and can accommodate more than 100 other planets that are identical.

Format of an IPv6 Address

An IPv6 address is composed of eight groups of 16 bits each, totalling 128 bits in length. Each group is represented by four hexadecimal digits, and colons are used to separate the groups.

A network component and a node component make up an IPv6 address. The first 64 bits of the address, which are used for routing, are the network component. To determine the address of the interface, the node component, which is the later 64 bits, is employed. It is derived from the physical address or MAC address, using the Institute of Electrical and Electronics Engineers (IEEE) EUI-644 format, which uses a 64-bit extended unique identifier.

A block of 48 bits, as well as a block of 16 bits, can be created from the network node. Global network addresses are stored in the upper 48 bits of the section. On an internal network, subnets are created using the lower 16-bit segment, which is managed by network administrators.

The sample address can also be shortened because the addressing system permits the omission of any starting zeros and any zero-only sequences. The condensed version would read as follows:

FE80:CD00:0:CDE:1257:0:211E:729C

Depending on its format, an IPv6 address may have a somewhat different layout. The routing prefix, subnet ID, and interface ID are the three fundamental components that make up an address.

The routing prefix, as well as the subnet ID, stand for the two primary levels, either global or site-specific, at which the address is built. The number of bits that can be separated into the route prefix is normally chosen by Internet Registries ISPs. The first 48 bits of an IPv6 address, which are the leftmost set of integers, are referred to as the site prefix. The following 16 bits are the subnet ID. The site topology is defined by the subnet ID. The interface ID, which is the final 64 bits, can be set either automatically or manually.

Types of IPv6 Addresses

There are several distinct IPv6 address types and formats; however, it’s important to note that IPv6 does not support broadcast addresses. Examples of IPv6 forms are as follows:

  • Global unicast: These addresses have the prefix group “2001:” and can be routed across the internet. Public IPv4 addresses are similar to global unicast addresses.
  • Unicast address: It is employed to pinpoint a certain node’s interface.
  • Anycast address: It is used to distinguish a collection of interfaces on several nodes.
  • Multicast address: A multicast address is used to specify when sending a single packet simultaneously to several locations.
  • Link-local addresses: It is one of the only two internal addresses that do not use internet routing. Internal networks employ link-local addresses, which are self-assigned and begin with the prefix group “fe80:”.
  • Unique local addresses: The other internal address type that is not routed over the internet is this one. Similar to the IPv4 addresses, 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 are unique local addresses.

Benefits of IPv6 Addresses

The benefits of IPv6 addresses include the following:

  • Aggregation of prefixes and smaller routing databases for more effective routing.
  • Reduced packet headers result in easier packet processing.
  • Support for packet flows for multicast.
  • IP addresses can be created by hosts themselves.
  • Does not require network address translation.
  • Greater security and easier implementation of services such as peer-to-peer networks and voice over IP (VoIP).

As for the two families of routing protocols used by IPv6, Interior Gateway Protocol and Exterior Gateway Protocol, they remain the same.

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