IPv6
IPv6 (Internet Protocol Version 6) is the version of internet protocol which supports the 128-bit IP addresses. It has been developed as the next generation protocol to increase the 4 billion IP Addresses available and it will eventually replace the nearly exhausted IPv4, which supports 32-bit address apace.[1] IPv6 has been developed to provide advantages over the current internet protocol. It is expected to solve several network problems by eliminating the need for Network Address Translation (NAT).
Background
In January 1991, the Internet Architecture Board (IAB) recognized the possibility of future problems on the current internet protocol due to the rapid growth of the inter AS routing table and the consumption internet address space. The IAB recommended the need for additional address flexibility. Based of this recommendation, the Internet Engineering Task Force (IETF) Road Group examined the consumption of address space and the exponential growth in inter-domain routing entries and subsequently evaluated several potential next generation IP protocols such as TUBA, SIP, PIP etc.[2]
By September of 1993, the IETF Road Group published RFC 1519 Classless Inter-Domain Routing (CIDR):An Address Assignment and Aggregation Strategy, which outline the outcome of the examination on the consumption of the address space. The Road Group enumerated three possible serious problems which include:[3]
- Exhaustion of the class B network address space.
- Growth of routing tables in Internet routers beyond the ability of current software, hardware, and people to effectively manage.
- Eventual exhaustion of the 32-bit IP address space.
In 1994,
- Easy address-autoconfiguration ("plug and play") and re-configuration
- Easier address management/delegation
- Room for more levels of hierarchy for route aggregation
- Built-in, strong IP-layer encryption and authentication (IPsec)
- Ability to do end-to-end IPsec (because NATs not needed)
- Reduced complexity, e.g., in IP header
- Upgrade in functionalities related to multicast, mobility and QoS
- Improved support for extensions/options