Cisco CCNA Security Introduction to Network Security
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Part 1 of 3 in the Cisco CCNA Security (640-554) series will teach you how to identify, lockdown, and secure vulnerabilities in a small to medium enterprise branch network.
PS : If You got an error while extracting while others are working try diferent directory path in your PC. Somtimes if you got a long directory path while extracting it will giv you an error. To solve this issue , as an example just paste the tgz file in C drive and extract (just inside the C drive not with in any other folder). Hope your Understand