IPv6 header
IPv6 header
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An IPv6 header is simplified in comparison to IPv4, minimizing complexity and making the header easier to process for all devices. Efficiency was one of the focus points with IPv6 from the onset, which is brought to light with the faster processing of IPv6 headers. The following figure displays the format of an IPv6 header:
Figure 38. IPv6 header
The following table defines the fields of an IPv6 header:
Table 13. IPv6 header fields
Field
Description
Length
Version
Specifies if the packet is IPv4 or IPv6
4 Bits
Traffic Class
Similar to an IPv4 Type of Service field and includes support for Differentiated Services Code Point (DSCP) providing congestion control
8 Bits
Flow Label
Provides the ability to track certain traffic flows at the network layer for QoS management
20 Bits
Payload Length
Similar to the IPv4 Length field – Provides length of the data portion
16 Bits
Next Header
Similar to the IPv4 Protocol field – Provides what to expect after the basic header, including options for a TCP or UDP header
8 Bits
Hop Limit
Similar to the IPv4 Time to Live field – Provides the maximum number of hops
8 Bits