IP version 6 (IPv6) is a new version of the Internet Protocol,designed as the successor to IP version 4 (IPv4) . Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4.
The changes from IPv4 to IPv6 fall primarily into the following categories:
- Expanded Addressing Capabilities
IPv6 increases the IP address size from 32 bits to 128 bits, to support more levels of addressing hierarchy, a much greater number of addressable nodes, and simpler auto-configuration of addresses. The scalability of multicast routing is improved by adding a “scope” field to multicast addresses. And a new type of address called an “anycast address” is defined, used to send a packet to any one of a group of nodes.
- Header Format Simplification
Some IPv4 header fields have been dropped or made optional, to reduce the common-case processing cost of packet handling and to limit the bandwidth cost of the IPv6 header.
- Improved Support for Extensions and Options
Changes in the way IP header options are encoded allows for more efficient forwarding, less stringent limits on the length of options, and greater flexibility for introducing new options in the future.
- Flow Labeling Capability
A new capability is added to enable the labeling of packets belonging to particular traffic “flows” for which the sender requests special handling, such as non-default quality of service or “real-time” service.
- Authentication and Privacy Capabilities
Extensions to support authentication, data integrity, and (optional) data confidentiality are specified for IPv6
IPv6 provides other technical benefits in addition to a larger addressing space. In particular, it permits hierarchical address allocation methods that facilitate route aggregation across the Internet, and thus limit the expansion of routing tables. The use of multicast addressing is expanded and simplified, and provides additional optimization for the delivery of services. Device mobility, security, and configuration aspects have been considered in the design of the protocol.