Network security is the keystone of IT security, and an important component of the Microsoft Technology Associate (MTA) Security Fundamentals exam (98-367). In this installment of Foundations of IT Security, series creator Lisa Bock will cover one of the main topics of the exam: securing an organization's network to keep interconnected systems and data safe. The course introduces security devices such as firewalls and packet inspectors, network isolation, and common security protocols. She also provides an overview of how to protect clients with antivirus software, encrypt offline files, and implement software restriction policies. Finally, she looks at the often-overlooked topics of mobile device and physical security, which includes securing a building's perimeter and the hardware within.