Trusted TCP connections

z/OS® TCP/IP stacks within a sysplex or a subplex communicate using the cross-system coupling facility (XCF). You can use XCF to exchange security information between application endpoints, which creates a trusted TCP connection. For more information about TCP/IP in a sysplex, see z/OS Communications Server: IP Configuration Guide.

An application end point can retrieve either or both of the following kinds of information for a partner end point:

• Sysplex-specific connection routing information

  An application can retrieve connection routing information by invoking the SO_CLUSTERCONNTYPE socket option or the SIOCGPARTNERINFO ioctl call. For more information, see Sysplex-specific connection routing information.

• Partner security credentials

  An application can retrieve partner security credentials by invoking the SIOCGPARTNERINFO ioctl call, optionally preceded by the SIOCSPARTNERINFO ioctl call. Partner security credentials can include the partner user ID, partner user security token (UTOKEN), or both. For more information, see Partner security credentials.