Intrusion Detection Systems and Intrusion Protection Systems on AWS come up when discussion security when moving to AWS. Here is short introduction to Oracle technologist that may not deal with IDS and IPS in their current on premise environment.
A host-based intrusion detection system (HIDS) is an intrusion detection system that monitors and analyzes the internals of a computing system, and in some cases the network packets on its network interfaces (just like an NIDS). A host-based IDS monitors all or parts of the dynamic behavior and the state of a computer system. HIDS was first designed for the mainframe. HIDS uses sensors (agents) located on each host. These host-based agents, which are sometimes referred to as sensors (or agents), would typically be installed on a machine that is deemed to be susceptible to possible attacks. The term “host” refers to an individual computer/virtual host. This means that separate sensor would be needed for every machine/virtual host. Sensors/agents work by collecting data about events taking place on the system being monitored. This data is recorded by operating system in audit trails. Therefore, HIDS is very log intensive.
Network-based intrusion detection systems offer a different approach. NIDS collects information from the network itself rather than from each separate host. They operate essentially based on a “wiretapping concept" (network taps). Information is collected from the network traffic stream, as data travels on the network. The intrusion detection system checks for attacks or irregular behavior by inspecting the contents and header information of all the packets moving across the network. The network sensors come equipped with “attack signatures” that are rules on what will constitute an attack, and most network-based systems allow advanced users to define their own signatures. this method is also known as packet sniffing, and allows the sensor to identify hostile traffic.