Dead Shaunak,
thank you so much for your assistance i appreciate it so much, i've solved my problem by doing this:
following this source kafka listeners, since producers came from different environment of kafka server i need to edit server.properties and add advertised.listeners. So i added advertised.listeners the same as listeners which is PLAINTEXT://hostname:6667. It still doesnt work. So i change both of hostname into IP as PLAINTEXT://IP:6667. And it finally works.
Once again thank you so much for your assistance.
Regards,
Charles