There is a need for IPv6 and IPv4 to coexist as some of the older devices might not even know how to communicate in IPv6. One example is IPv4-mapped address space.
IPv6 specifications have set aside a number of addresses that can be directly correlated to an IPv4 address. Any IPv6 address begins with 80 zeros and is then followed by 16 ones, is understood to be part of the IPv4-mapped address space.
Servers take incoming IPv6 traffic and encapsulate it within traditional IPv4 datagram
Companies that provide IPv6 tunneling endpoints for you, so you don’t have to introduce additional equipment to your network.