Upon completion of this chapter, you will be able to answer the following questions:
• Why do we need for IPv6 addressing?
• How do you represent IPv6 addresses?
Network Address Translation 64 (NAT64)
Kishori meets Rina for lunch again. Kishori is excited to tell Rina all that she has learned about IPv4 addresses. Rina congratulates her and asks her if she has heard about IPv6. IPv6? Kishori has no idea what IPv6 is! Do you? Let me help you out with that. Let’s get started with this module!
This topic will examine the reasons for the migration to IPv6.
You already know that IPv4 is running out of addresses. That is why you need to learn about IPv6.
IPv6 is designed to be the successor to IPv4. IPv6 has a larger 128-bit address space, providing 340 undecillion (i.e., 340 followed by 36 zeroes) possible addresses. However, IPv6 is more than just larger addresses.
When the IETF began its development of a successor to IPv4, it used this opportunity to fix the limitations of IPv4 and include enhancements. One example is Internet Control Message Protocol version 6 (ICMPv6), which includes address resolution and address autoconfiguration not found in ICMP for IPv4 (ICMPv4).
The depletion of IPv4 address space has been the motivating factor for moving to IPv6. As Africa, Asia and other areas of the world become more connected to the internet, there are not enough IPv4 addresses to accommodate this growth. As shown in the figure, four out of the five RIRs have run out of IPv4 addresses.
Figure 10-1 RIR IPv4 Exhaustion Dates
IPv4 has a theoretical maximum of 4.3 billion addresses. Private addresses in combination with Network Address Translation (NAT) have been instrumental in slowing the depletion of IPv4 address space. However, NAT is problematic for many applications, creates latency, and has limitations that severely impede peer-to-peer communications.
With the ever-increasing number of mobile devices, mobile providers have been leading the way with the transition to IPv6. The top two mobile providers in the United States report that over 90% of their traffic is over IPv6.
Most top ISPs and content providers such as YouTube, Facebook, and NetFlix, have also made the transition. Many companies like Microsoft, Facebook, and LinkedIn are transitioning to IPv6-only internally. In 2018, broadband ISP Comcast reported a deployment of over 65% and British Sky Broadcasting over 86%.