IPv6

Overview

While IPv4 was tremendously successful in handling virtually every demand placed on it as the Internet grew exponentially, it was limited in several significant ways. As a result, the IETF made the decision in the mid-90's to develop and implement a improved version. It took several years for the engineering and political problems to be resolved, but IPv6 (what happened to IPv5?) is the successor. It has to be able to coexist with previous versions, because the migration to the new system will be evolutionary. Some places are already using it while others are waiting. Over the next decade or so, you will see most of the Internet moving to IPv6. Not surprisingly, much of the slowness is the result of political, not engineering, problems.

What's Important

What is important to learn in this unit is why there was a need for IPv6 and why it was designed the way that it was. Why were certain changes made and what impact will they have on the performance and useability of IP networks.

Preparation

Read section 4.3.5 in the text and the notes.

Knowledge, Comprehension and Problem Solving

Terms

Questions

  1. If the surface area of the earth is 4 x 10^20 square meters. How many addresses per square meter does IPv6 provide? Explain why this number is relatively meaningless in terms of the determining the efficacy of the address space in serving future needs? (think about how addresses are distributed)
  2. What is the relationship between IPv6 flow labels and virtual circuits?
  3. An IPv6 packet has security, routing and hop-by-hop options. What is the format of the packet?

Knowledge, Comprehension and Problem Solving

  1. Will the advent of IPv6 change routing methodologies? In what way?
  2. How will IPv6 flow label field be advantageous?
  3. How significant is the use of source host fragmentation in IPv6? Do you think this is a good idea or not?
  4. Security is often an issue of national boundaries. Should security be included in IPv6 or not?
  5. Is 8-bit hop count reasonable?