IPv4 and IPv6 networks are not interoperable and the number of devices that use IPv4 number is still great. Some of these devices do not support IPv6 at all, so the migration process is necessary since IPv4 and IPv6 will likely coexist for some time.
Many transition mechanisms have been proposes. We will introduce the main ones and describe them in the next sections:
1. IPv4/IPv6 Dual Stacks
NOTE – some methods of the IPv4-IPV6 transition have been deprecated, but they are still mentioned in the older books. Some of these methods are NAT-PT and NAPT-PT.