The deployment of IPv6 in an IPv4 world and transition strategies
Introduction The IP protocol and its current version, IP version 4, is the most widely used protocol in computer networks at present. The big change that happened to the character of the Internet, from a rather academic network with low demands on resources to a commercial network with a variety of intensive applications running over it -considering also the integration of other communication services on it, e.g. VoIPshowed the weakness of the fourth version to support the new networking
... tions. The reasons that led the Internet community to adopt the development of a new IP version are summarized below: Lack of addresses. The address space of IPv4 is 232. This space is decreasing because of the sub netting procedure and the dedicated areas in the IP space for several operations like private networks and multicasting. The IP space that has been left is running out. There are new demands for IPs, while new devices tend to connect to the IP networks, such as home devices and mobile phones. Performance-manageability. The lack of hierarchy levels in IP addresses results in the existence of too many hard-to-manage routing entries to the routers. Also, several applications demand quality of service (QoS) support from IPv4 and this shortcoming is overtaken by the use of protocols in higher levels with uncertain results. Security.Considering the wide spread of the Internet and its use for several transactions, like financial ones, security is an issue that has to be supported by the IP protocol, which must be able to provide reliable and efficient security mechanisms. Automatic address assignment. The configuration procedure in IPv4 hosts is complex and requires human interference. Users would prefer a procedure of the type "plug and play". When a computer is plugged to the IP network, the connection parameters may be configured automatically without human interference. This capability is suitable enough for mobile users. Abstract It is stated that the new version of the IP protocol, IPv6, is the answer to the majority of the problems that were raised during the enormous expansion of the Internet and its transformation to a global communication platform with commercial scope. At the same time it is also stated that IPv6 dominance will not be easy and there will be a period when the two versions of the protocol will co-exist. In this paper we describe some of the main transition mechanisms that can be deployed in order to facilitate the transition process to the new version of the IP protocol. Furthermore, the presented mechanisms are discussed regarding their usability, usefulness and manageability. Describes the way some of these mechanisms were applied to the Greek Research & Technology Network (GRNET).