IPv6 is an extension of IP with several advanced features:
Larger address space
“Baked in” security
Of these, many capabilities have been backported to IPv4. The primary adoption of IPv6 will be driven by the need for more addresses. Given the growth in Internet use and the emergence of large groups of Internet users in developing countries, this is a significant requirement.
IPv4 addresses are 32 bits long, whereas IPv6 addresses are 128 bits. IPv6 addresses are composed of the following elements (see Figure 8-1):
Figure 8-1. RFC 2374 IPv6 ...