Field | Size in bits |
---|---|
Ver—Internet Protocol version number, with a value of 6 | 4 |
DS byte—Traffic class field, similar to Type of Service in IPv4 | 8 |
Flow label—identifies traffic flow for additional Quality of Service (QoS) | 20 |
Payload Length—Unsigned integer, the length of the IPv6 payload | 16 |
Next header selector—identifies the next header | 8 |
Hop limit unsigned integer—decrements by 1 each time a node forwards the packet (nodes discard packets with hop limit values of 0) | 8 |
Source address | 128 |
Destination address | 128 |
The following figure illustrates the basic IPv6 header, without extension headers.