IPV6

                 Due to recent concerns over the impending depletion of the current pool of Internet addresses and the desire to provide additional functionality for modern devices, an upgrade of the current version of the Internet Protocol (IP), called IPv4, has been defined. This new version, called IP version 6 (IPv6), resolves unanticipated IPv4 design issues and takes the Internet into the 21st Century. To address these and other concerns, the Internet Engineering Task Force (IETF) has developed a suite of protocols and standards known as IP version 6 (IPv6). This new version, previously called IP-The Next Generation (IPng), incorporates the concepts of many proposed methods for updating the IPv4 protocol. The design of IPv6 is intentionally targeted for minimal impact on upper and lower layer protocols by avoiding the random addition of new features.


IPv6 (Internet Protocol version 6) is a set of specifications from the Internet Engineering Task Force (IETF) that's essentially an upgrade of IP version 4 (IPv4).

 

IPv6 is the next generation protocol for Internet networking. IPv6 expands on the current Internet Protocol standard known as IPv4. Compared to IPv4, IPv6 offers better addressing, security and other features to support large worldwide networks.


In IPv6, IP addresses change from the current 32-bit standard and dotted decimal notation to a new 128-bit address system. IPv6 addresses remain backward compatible with IPv4 addresses. For example, the IPv4 address "192.168.100.32" may appear in IPv6 notation as "0000:0000:0000:0000:0000:0000:C0A8:6420" or "::C0A8:6420".


The most obvious benefit of IPv6 is the exponentially greater number of IP addresses it can support compared to IPv4. Many countries outside the U.S. suffer from a shortage of IP addresses today. Because IPv6 and IPv4 protocols coexist, those locales with an address shortage can easily deploy new IPv6 networks that work with the rest of the Internet. Experts believe it will take many more years before all networks fully change over to IPv6.


Other benefits of IPv6 are less obvious but equally important. The internals of the IPv6 protocol have been designed with scalability and extensibility in mind. This will allow many different kinds of devices besides PCs, like cell phones and home appliances, to more easily join the Internet in future.


 IPv6 uses 128-bit addresses, so the new address space supports 2128undecillion or (approximately 340 3.4×1038) addresses. This expansion allows for many more devices and users on the internet as well as extra flexibility in allocating addresses and efficiency for routing traffic. It also eliminates the primary need for network address translation (NAT), which gained widespread deployment as an effort to alleviate IPv4 address exhaustion. IPv6 also implements additional features not present in IPv4. It simplifies aspects of address assignment (stateless address autoconfiguration), network renumbering and router announcements when changing Internet connectivity providers. The IPv6 subnet size has been standardized by fixing the size of the host identifier portion of an address to 64 bits to facilitate an automatic mechanism for forming the host identifier from link layer media addressing information (MAC address). Network security is also integrated into the design of the IPv6 architecture, and the IPv6 specification mandates support for IPsec as a fundamental interoperability requirement.