Start the APPN route selection trace with the MODIFY TRACE,TYPE=ROUTE command and stop the trace with the MODIFY NOTRACE,TYPE=ROUTE command. The status of the APPN route selection trace and the amount of storage allocated to the trace table can be displayed with the DISPLAY TRACES,TYPE=ROUTE command. For more information about the MODIFY TRACE, the MODIFY NOTRACE, and the DISPLAY TRACES commands, see z/OS Communications Server: SNA Operation.