This is a network simulator created by Cisco. It is essential. You can build virtual networks, configure routers and switches, and troubleshoot scenarios without buying physical hardware.

The following resources are widely considered the gold standard for self-study:

The consensus among the networking community is that is currently the best free course for the Cisco CCNA (200-301). It is widely praised for being a complete, high-quality, and structured curriculum that includes not only video lectures but also essential study tools like Anki flashcards and Packet Tracer labs .

Professor Messer's YouTube channel offers a comprehensive CCNA course with over 100 video lectures. The course covers all aspects of the CCNA curriculum, including networking fundamentals, routing, switching, and troubleshooting. The videos are well-produced, engaging, and easy to follow.

The Best Free Cisco CCNA Courses to Jumpstart Your Networking Career (2026)