In the early 1990s, the Internet Engineering Task Force (IETF) grew concerned about the issues with IPv4 and began to look for a replacement. Internet Protocol version 6 is the most recent version of the Internet Protocol, the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet.
What is IPv6 – Introducing IPv6
This activity led to the development of IP version 6 (IPv6). IPv6 overcomes the limitations of IPv4 and is a powerful enhancement with features that better suit current and foreseeable network demands. IPv6 was necessitated by the phenomenal increase in devices accessing the Internet. Because of this increase, the Internet is running out of IPv4 addresses. The solution is for IPv6 to accommodate this increased demand by providing a larger address space.
Improvements that IPv6 provides include:
Increased address space – IPv6 addresses are based on 128-bit hierarchical addressing as opposed to IPv4 with 32 bits.
Improved packet handling – The IPv6 header has been simplified with fewer fields.
Eliminates the need for NAT – With such a large number of public IPv6 addresses, NAT between a private IPv4 address and a public IPv4 is not needed. This avoids some of the NAT-induced application problems experienced by applications requiring end-to-end connectivity.
The 32-bit IPv4 address space provides approximately 4,294,967,296 unique addresses. In IPv4, Host (A) records are used to map an IP address to a host name. DNS is stillused in IPv6, but Host (A) records are not used by IPv6 addresses. Instead, IPv6uses AAAA resource records, which are sometimes referred to as Quad A records. The domain ip6.arpa is used for reverse hostname resolution. IPv6 address space provides 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses, which is roughly equivalent to every grain of sand on Earth.