What is the IPv6 header format?

A. Below is the specification for the header format of IPv6:

Version - 4-bit Internet Protocol version number.

Traffic Class - 8-bit traffic class field

Flow Label - 20-bit flow label

Payload Length -16-bit unsigned integer. Length of the IPv6 payload,i.e., the rest of the packet following this IPv6 header, in octets. (Note thatany present are considered part of the payload, i.e., included in the lengthcount.)

Next Header - 8-bit selector. Identifies the type of header immediatelyfollowing the IPv6 header. Uses the same values as the IPv4 Protocol field[RFC-1700 et seq.].

Hop Limit - 8-bit unsigned integer. Decremented by 1 by each node thatforwards the packet. The packet is discarded if Hop Limit is decremented tozero.

Source Address - 128-bit address of the originator of the packet.

Destination Address - 128-bit address of the intended recipient of thepacket (possibly not the ultimate recipient, if a Routing header ispresent).

Notice that the IPv6 header has far less fields than the IPv4 header andIPv6 introduces a number of extension headers as defined in RFC2460.