Book excerpt: This book discusses how built-in and third-party networking tools can be used to diagnose network problems and performance issues as well as enhance the security of computer systems. The author covers a variety of networking tools and demonstrates how they can be used to determine ahead of time whether or not existing Internet connectivity can support such activities as voice and video over IP. Coverage of other tools shows readers how to prevent keyboard hacking and negate the operation of unwanted advertisement trackers through checking for and eliminating different types of attack software.