Understanding IDS for Linux

Do you feel your network is safe? Do you really know what is happening on your network right now? Once upon a time, there were network administrators who thought that the solution to their security was a simple firewall. In the past few years, we have verified that this is not true anymore.

The need for some element that could alert and inform administrators about something strange in near real time resulted in intrusion detection systems (IDSes). In this article we discuss the types and models of IDSes: the host-based intrusion detection system (HBIDS), the network intrusion detection system (NIDS) and the new concept of hybrid-IDS.

How to analyze the data generated and how to create signatures (the patterns that identify the attacks) also are discussed, as well as some examples of IDSes for Linux, like the open-source NIDS Snort.