Security Basics: Know What's on Your Network

This post is one in a series of blog posts on the fundamentals of an information security program. You can see the complete list of posts in this series here . The most basic of basic security principles is that you must know what you are defending in order to defend it. It sounds obvious at first blush, but it is an oft-neglected step in securing your network, your systems, and your information. Getting a handle on what devices are present on your network is essential to a proper security program. One of the notes in the Office of Personnel Management (OPM) Inspector General's report on their systems security in November 2014 (just before they suffered a massive breach) was that the office did not "maintain a comprehensive inventory of servers, databases, and network devices." 1 This shortcoming clearly underlies many of the other shortcomings there, including the failure to conduct comprehensive vulnerability scans -- you can't be sure if you're scanning...