Dr. Mustafa ElGili Mustafa2017-07-242017-07-2420171858-6228http://hdl.handle.net/123456789/4166IP internet protocol is the set of technical rules or standards which set forth that how computer communicates over a network. Internet protocol version 4 IPV4 has been introduced in 1981. But the growth of internet applications causes space exhausting . Moreover, IPV4 based internet causes problems of IP addressing space depletion and routing overhead[1] . Some temporary solutions were offered, such as NAT (Network Address Translator) or CIDR (Classless InterDomain Routing) , however work began on a new Internet Protocol, namely IPv6[2]. IPv6 is a new version of internet protocol designed as a successor to the current ipv4[1]. The main reason for a new version of the Internet Protocol was to increase the address space; IPv6 was designed with a 128 bit address scheme, enough to label every molecule on the surface of the earth with a unique address [2]. IPv6 - originally known as IPng- has been selected from several proposed alternatives as a suitable successor of the existing Internet Protocol (IPv4) [3]. Most of the existing protocol stacks, systems and applications run on IPv4-based systems. Changes to these systems can have significant impact on existing applications and must therefore be carefully implemented. While a principal design objective of IPv6 was to ease the transition from and coexistence with IPv4, the migration of IPv4-based systems to IPv6 will be a major challenge despite IPv6’s built-in features that are backward-compatible with IPv4[4]. It is envisioned that the transition from IPv4 to universal IPv6 will not happen in the near future