ORA-02082: a loopback database link must have a connection qualifier

SQL> CREATE DATABASE LINK "muthu"
 CONNECT TO APPS
 IDENTIFIED BY <PWD>
 USING '10.2.0.189:1521/orcl';
CREATE DATABASE LINK "muthu"
 CONNECT TO APPS
 IDENTIFIED BY <PWD>
 USING '10.2.0.189:1521/orcl'
*
ERROR at line 1:
ORA-02082: a loopback database link must have a connection qualifier

Solutin :-

a loopback database link needs a trailing qualifier, e.g.
  muthu.kirthi.com - the 'kirthi.com' is the qualifier

 CREATE DATABASE LINK "muthu.kirthi.com"
 CONNECT TO APPS
 IDENTIFIED BY <PWD>
 USING '10.2.0.189:1521/orcl';