REM Edit the D:\oracle\product\12.2.0\dbhome_1\network\admin\sqlnet.ora 
## For Windows ONLY, to connect internal:
SQLNET.AUTHENTICATION_SERVICES = (NTS)
## Std for all environments:
NAMES.DEFAULT_DOMAIN = {enter domain}
##
## following 2 lines required for all 12.2 homes for client backward compatibility:
SQLNET.ALLOWED_LOGON_VERSION_SERVER=8
SQLNET.ALLOWED_LOGON_VERSION_CLIENT=8
##
## following 2 lines required after upgrade from 12.1 to 12.2, so all 12.2 home should have this for now Doc ID 2373121.1:
SQLNET.CRYPTO_CHECKSUM_SERVER=rejected
SQLNET.ENCRYPTION_SERVER=rejected
##