Before using SNC you have to configure the TREX configuration file sapprofile.ini for SNC.
Open the configuration file sapprofile.ini in a text editor.
You will find the configuration file in the following directory of your TREX installation:
On UNIX /usr/sap/<sapsid>/trx<instance_number>/<trex_hostname>
On Windows <disk_drive>:\usr\sap\<SAPSID>\TRX<instance_number>\<trex_hostname>
Set the entry snc/enable/as to the value used in section Configuring SNC on TREX Side
snc/identity/as=p:CN=$<SAPSID>-TRX$<SAPSYSTEM>,O=SAP,C=DE
Switch SNC on by setting the entry snc/enable=1.
Leave unchanged the entry snc/data_protection/use.