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Also known as IPng (next generation) Developed to alleviate IPv4 address exhaustion A new version of the Internet Protocol Improve upon IP protocol based on operational experience of IPv4 in the Global Internet 128 bit addressing Simplified header makes forwarding algorithms more efficient New extensions and options IPv6 provides a platform for new Internet functionality that will be needed in the immediate future, and provide flexibility for further growth and expansion 2

Larger Address Space Flexible Header Format Improved Options Provision for Protocol Extension Support for Auto-configuration and Renumbering Security Efficient and extensible IP datagram Routing 3

IPv4 32 bits= 4,294,967,296 possible addressable devices IPv6 128 bits: 4 times the size in bits = 3.4 x 1038 possible addressable devices = 340,282,366,920,938,463,463,374,607,431,768,211,456 ∼ 5 x 1028 addresses per person on the planet 4

IPv6 Addressing rules are covered by multiples RFCs Architecture defined by RFC 4291 Address Types are : Unicast : One to One (Global, Unique Local, Link local) Anycast : One to Nearest (Allocated from Unicast) Multicast : One to Many A single interface may be assigned multiple IPv6 addresses of any type (unicast, anycast, multicast). No Broadcast Address. 5

VersionIHLType of ServiceTotal Length IdentificationFlags Fragment Offset Time to LiveProtocolHeader Checksum Source Address Destination Address OptionsPadding VersionTraffic ClassFlow Label Payload Length Next Header Hop Limit Source Address Destination Address IPv4 Header Header IPv6 Header - field’s name kept from IPv4 to IPv6 - fields not kept in IPv6 - Name & position changed in IPv6 - New field in IPv6 Legen d 6

next header = TCP TCP header + data IPv6 header next header = Routing TCP header + dataRouting header next header = TCP IPv6 header next header = Routing fragment of TCP header + data Routing header next header = Fragment Fragment header next header = TCP IPv6 header 7

Routing – Extended routing, like IPv4 loose list of routers to visit Fragmentation – Fragmentation and reassembly Authentication – Integrity and authentication, security Encapsulation – Confidentiality Hop-by-Hop Option – Special options that require hop-by-hop processing Destination Options – Optional information to be examined by the destination node 8

IP v6 DATAGRAM HEADER AND PAYLOAD 9 IP V6 PACKET Each packet is composed of a mandatory base header followed by the payload. The payload consists of two parts optional extension headers and data from an upper layer. The base header occupies 40 bytes, whereas the payload contains upto 65,535 bytes of information.

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