Testing for Understanding

To test your understanding of the IPv6 header, answer the following questions. See Appendix D, "Testing for Understanding Answers" to check your answers.

1. Why does the IPv6 header not include a checksum?
2. What is the IPv6 equivalent to the IHL field in the IPv4 header?
3. How does the combination of the Traffic Class and Flow Label fields provide better support for QoS traffic?
4. Which extension headers are fragmentable and why? Which extension headers are not fragmentable and why?
5. Describe a situation that results in an IPv6 packet that contains a Fragment Header in which the Fragment Offset field is set to 0 and the More Fragments flag is not set.
6. Describe how the new upper-layer checksum calculation affects transport layer protocols such as TCP and UDP.
7. If the minimum MTU for IPv6 packets is 1,280 bytes, then how are 1,280-byte packets sent on a link that supports only 512-byte frames?