To find NPF.DATA, NPF follows a standard search sequence. It reads each instance of NPF.DATA it can find, in order, until it finds values for all the NPF configuration statements. It uses the first value that it finds for each statement. If an allocation fails, the data set does not exist, or the data set is not available, NPF goes to the next data set in the sequence. The search ends when it finds values for all NPF configuration statements or when all data sets have been checked.

The search order is:

1. The data set pointed to by a DD statement //SYSNPFD.
2. A data set with the name of jobname.NPF.DATA, where jobname is the jobname for the NPF capture point application or the user ID for the TSO session (panels).
3. A data set with the name of SYS1.TCPPARMS(NPFDATA).
4. A data set with the name of hlq.NPF.DATA, where hlq is the value specified by the DATASETPREFIX statement in TCPIP.DATA. If TCPIP.DATA cannot be found or does not contain a DATASETPREFIX statement, then hlq is the system default, TCPIP.