(This series of courses are explained by Microsoft OneNote + MindManager / XMIND tools, combined with GNS3, SecureCRT and Wireshark for actual combat projects, abandoning the traditional ppt method of "turning over the book" theory teaching, from theory to practice. All classroom notes, concept explanation, topology analysis, experimental verification, project practice, etc. are available! In addition, this course interprets the grouping of various protocols through packet capturing software, so that you can understand the beauty of the underlying data! This course is suitable for all rookies / novices who are learning computer network and security, junior and senior network and security engineers, and friends who are struggling on the road of CCNA / CCNP / CCIE!)