
112 n Handbook of IPv4 to IPv6 Transition
of the remaining fields is straightforward with a couple of exceptions (e.g., the case
of an IPv6
fragment extension header), which are covered in detail in the RFC. If
there is no IPv6
fragment header, the IPv4 header fields are set as follows:
Version: 4.
Internet Header Length: 5 (no IPv4 options).
Type of Service and Precedence: By default, copied from the IPv6 Traffic
Class (all eight bits).
Total Length: Payload length value from IPv6 header plus the size of the IPv4
header.
Identification: All zero.
Flags: e More Fragments flag is set to zero, the Don’t Fragment flag is set
to one, and the fragment offse ...