This chapter includes several hacks that demonstrate some security mechanisms that aren't well-documented elsewhere. I've also provided some new twists on old security favorites. Everyone has heard of sudo, but are you also aware of the security pitfalls it can introduce? You're probably also well-versed in ssh and scp, but you may have yet to harness the usefulness of scponly.
You'll also find several scripts to automate some common security practices. Each provides an excellent view into another administrator's thought processes. Use their examples to fuel your imagination and see what security solutions you can hack for your own network.