You can achieve CCNA certification in two ways:
The CCNA 640-802 exam includes the same topics covered by the ICNDv1 640-822 and ICNDv2 640-816 exams . Cisco developed the second approach particularly for individuals who are just beginning their journey into networking, especially for people taking the CCNA curriculum at a Cisco Network Academy. The two-test approach is better suited for this environment since it takes a year to two to go through Cisco’s CCNA curriculum at the Network Academies. With this approach, you take the ICNDv1 640-822 exam halfway through the curriculum and the ICNDv2 640-816 exam at the end of the curriculum.
Another advantage of taking and passing the ICNDv1 exam is that you have achieved Cisco’s newest entry-level certification: CCENT (Cisco Certified Entry Networking Technician). In August 2007, Cisco introduced this certification based on customer and employer demand for a lower level certification demonstrating basic networking and hand-on skills with IOS devices such as routers and switches. If you already have networking experience, especially if that experience includes configuring Cisco devices, you are better off taking the single CCNA 640-802 exam. The main advantage of this approach is that you have to pay for only one exam.