To display the TCPIP.DATA information found in the search order, you can use the z/OS® Communications Server resolver trace support. To activate the trace, you can set the RESOLVER_TRACE environment variable before invoking the hostname command. Setting the environment variable to use stdout is recommended. The resolver trace is described in z/OS Communications Server: IP Diagnosis Guide.
See z/OS Communications Server: IP Configuration Reference for detailed information about TCPIP.DATA statements. The z/OS UNIX search order is always used to find the TCPIP.DATA statements for the hostname command. See information about search orders used in the z/OS UNIX environment in z/OS Communications Server: IP Configuration Guide for a description of this search order.