To gain the CCNA certification you can either take two exams or combine them into one single exam.
If you decide to take the split route, the two exams will include:
- 100-101 – Interconnecting Cisco Networking Devices Part 1 (ICND1)
- 200-101 – Interconnecting Cisco Networking Devices Part 2 (ICND2)
If decide you only want to take one test, the exam will include:
- 200-120 – Interconnecting Cisco Networking Devices (Composite)
When studying for these exams, it’s best to prepare the way that works for you. For those who have some experience with networking, self-study is a popular option, and you can do so using any number of available resources.
For most people at the CCNA level, using a product like GNS3 combined with computer-based training is an excellent approach. For the CCNA R&S exams, make sure you understand the fundamentals, IP subnetting, addressing and basic routing, before looking at other topics.
Go through all of the topics in IOS and learn them, configure them and figure out how and why they work. Cisco IOS is generally a well-documented OS. Cisco also has a very active certification support community that can provide specific advice as issues arise.