DSNCLI is the CICS-DB2 Language Interface module.
DSNCLI is no longer shipped by the DB2® product. DSNCLI is supplied as part of CICS® and is installed in the SDFHLOAD library when you install CICS TS. Note that DSNCLI is an alias of DFHD2LI.
DSNCLI is also installed in the SDFHAUTH APF-authorized library. In this library, DSNCLI is an alias of DFHD2LIX.