Here indicate that some of the main modifications of IPv6 over IPv4. Specialists have an incentive to consult the various links that we propose to obtain a more complete answer.
First, the address length was extended, allowing the existence of more places. An IPv6 address is 128 bits in length while an IPv4 address is 32 bits long. Therefore available with IPv6 addresses 2128 or 340 282 366 920 938 463 463 374 607 431 768 211 456 adressses. This equals about 67 billion billion addresses per square millimeter of the earth’s surface (around 1016 66.7133897 × addresses, to be a little more specific)!
The IP packet has been simplified, while allowing you to add extensions for new features. This speeds up the routing and introduce concepts including QoS, security and mobility at the IP, filling large gaps in IPv4.
Besides better routing efficiency, some changes also allow a better adaptation to the constraints of existing and future networks.
Finally, to facilitate the migration from IPv4 interoperability mechanisms and connections between IPv4 and IPv6 have been introduced.