Figure 2: IPv6 header Format (RFC 1883, IPv6 Specification, December 1995)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Version | Prio. | Flow Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| + Payload Length | Next Header | Hop Limit +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| + + | | + Source Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| + + | | + Destination Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Version: 4-bit Internet Protocol version number = 6. Prio.: 4-bit priority value. Flow Label: 24-bit flow label. Payload Length: 16-bit unsigned integer. Length of payload (i.e., the rest of the packet following the IPv6 header, in octets). If zero, indicates that the payload length is carried in a Jumbo Payload hop-by-hop option. Next Header: 8-bit selector. Identifies the type of header immediately following the IPv6 header. Uses the same values as the IPv4 Protocol field. Hop Limit: 8-bit unsigned integer. Decremented by 1 by each node that forwards the packet. The packet is discarded if Hop Limit is decremented to zero. Source Address: 128-bit address of the originator of the packet. Destination Address: 128-bit address of the intended recipient of the packet (possibly not the ultimate recipient, if a Routing header is present).
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