IP version 6

IPv6 is a new version of the IP protocol. The current version IPv4 had a limited number of IP addresses (2^32 addresses), and there was a need to connect more hosts. Hence IPv6 allows for a 128-bit address field compared to a 32-bit address field in IPv4. Hence, IPv6 can have 2^128 unique IP addresses. IPv6 also provides some new features and does away with some features of the IPv4 packet such as fragmentation and Header checksum. Figure 13 shows the IPv6 header and shows the various fields of the IPv6 header:

We will not go into the details of IPv6 in this book, but will cover it as and when required during the discussion on design and implementation.