/aɪ.diː.ɛs/
noun — "the alarm system that spots network threats before they strike."
IDS, short for Intrusion Detection System, is a security tool that monitors network or system activity for suspicious behavior or policy violations. It identifies potential attacks, unauthorized access, and malicious activity, alerting administrators so they can respond quickly.
Technically, IDS can operate in two modes: signature-based, which compares traffic against known threat patterns, and anomaly-based, which detects deviations from normal behavior. It often integrates with firewalls (Firewall), VPNs (VPN), and SIEM systems for comprehensive security monitoring.
Key characteristics of IDS include:
- Detection: identifies intrusions, malware, or suspicious activity.
- Alerts: notifies administrators in real-time or via logs.
- Analysis: can perform signature matching or anomaly detection.
- Integration: works with firewalls, VPNs, and other security tools.
- Non-intrusive: monitors without directly blocking traffic (contrast with IPS).
In practical workflows, IDS devices are deployed at network perimeters or critical internal segments to monitor traffic, detect policy violations, and provide alerts for potential security breaches.
Conceptually, an IDS is like a security camera system for your network: it watches, recognizes suspicious behavior, and raises the alarm before damage occurs.
Intuition anchor: IDS keeps networks aware of threats without actively stopping them.