Understanding Network Intrusion Detection Systems
A Network Intrusion Detection System (NIDS) is a bit like the early warning alarm sirens that we see and hear in prison escape movies. These are triggered by a predefined event (such as an attempted break in/out) that is identified by a rule set enabled by the administrator/investigator. Just like a burglar alarm in a house, the NIDS is designed to detect an intruder and issue an alert to an authorized person.
Normally, a NIDS is able to detect intrusions in the network segment that it is monitoring. The key to its effective functioning is the correct placement of the NIDS device to enable it to monitor all network traffic entering and leaving the system. One way to do this is by placing it on the network and passing mirrored traffic through it. This is done to ensure that all the network traffic passes through the NIDS device.
The NIDS will monitor all inbound and outbound traffic and identify attempted intrusions by detecting anomalous...
