For native IPv4 addresses, the application must create an AF_INET address family socket. For native IPv6 addresses and IPv4-mapped IPv6 addresses, the application must create an AF_INET6 address family socket. See z/OS Communications Server: IPv6 Network and Application Design Guide and the SOCKET command under the APIs that support IPv6 for details.
For details on which TCP/IP APIs and commands support the AF_INET6 (IPv6) address family, see Address family cross reference.