RFC 2549 (IPv4 over IPv6)

RFC 2549 describes a method for sending Internet Protocol version 4 (IPv4) data over Internet Protocol version 6 (IPv6) networks. It essentially allows older IPv4 data packets to be encapsulated within newer IPv6 packets. This is useful during the transition from IPv4 to IPv6, helping ensure that IPv4 services can continue to operate while more modern networks adopt IPv6. This approach enables compatibility between different network technologies during a time when both protocols are in use, allowing smooth communication and data exchange across diverse systems.