Learn and Prepare Cisco CCNA Course Exam 200-120. Basics of Networking Cisco, CCNA. 200-125 ccna. You can learn the basics general networking concepts through this app and you can prepare the Cisco CCNA Exam 200-120 or 200-125 easily. Contents of the Cisco CCNA Course/Exam. Duction. Computer network explained. OSI reference model. TCP/IP reference model. Data encapsulation.