This is something basic to know , perhaps there might be an urgent time where the ./netca application is not starting due to some issue with java or something else, but you need yo make some changes on the configuration of a listener or a directory service, what to do then? Ok , simply use the locate command to look for one of the files below, which are managed by ./netca If necessary, modify the Oracle Net configuration files (tnsnames.ora, listener.ora, and sqlnet.ora) found in $TNS_ADMIN (if you specified that variable) or $ORACLE_HOMEhttp://felipecruz.com/admin (typically the primary default location).