DSNT519I TO SPECIFY A DRDA PORT OR A SECURE PORT (OR BOTH) YOU MUST ALSO SPECIFY A RESYNC PORT.

Explanation
 You entered a value for DRDA PORT
or SECURE PORT but not for RESYNC PORT, or, you entered a value for
RESYNC PORT but did not enter a value for either DRDA PORT or SECURE PORT. 

 When DRDA PORT, SECURE
PORT, or both contain a non-blank, RESYNC PORT must also contain a
non-blank.
  This message is issued by the following panel:
DSNTIP5

System action
  The panel is redisplayed and the cursor is placed
on the field in error.

User response
  Enter values for DRDA PORT, SECURE PORT, or both,
in conjunction with a value for RESYNC PORT. Or, remove all of the
values from all of the port fields.