If you getting the ORA-30683 error when attempting to connect database via SQL Developer:
Connecting to the database ORCLDB. Executing PL/SQL: CALL DBMS_DEBUG_JDWP.CONNECT_TCP( '192.168.121.104', '54070' ) ORA-30683: failure establishing connection to debugger ORA-12535: TNS:operation timed out ORA-06512: at "SYS.DBMS_DEBUG_JDWP", line 68 ORA-06512: at line 1 Process exited. Disconnecting from the database ORCLDB.
Execute below command then try to connect again.
GRANT DEBUG CONNECT SESSION TO <USER>; GRANT DEBUG ANY PROCEDURE TO <USER>;
BEGIN DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE( host => '192.168.121.104', lower_port => null, upper_port => null, ace => xs$ace_type( privilege_list => xs$name_list('jdwp'), principal_name => '<USER>', principal_type => xs_acl.ptype_db ) ); END;
select * from dba_network_acl_privileges where principal = '<USER>' and privilege = 'JDWP' order by acl, aclid, privilege;