LSNRCTL> set trc_level 16 R12DEV NL-00857: wrong number (0 - 1 needed) of arguments to "trc_level"

When one of my friend tried to enable the trace for listener.

he got,
LSNRCTL> set trc_level 16 R12DEV
NL-00857: wrong number (0 - 1 needed) of arguments to "trc_level"


The correct syntax is

LSNRCTL> set current_listener R12DEV
Current Listener is R12DEV

LSNRCTL> set trc_level 16
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=XXX.XXX.XXX)(PORT=1531)))
MIGRATE parameter "trc_level" set to support
The command completed successfully


Hope this helps.