DataTerminology.comNEW
Also known as: IDS
A system that monitors networks or hosts to detect malicious activity or policy violations and generates alerts.
DESCRIPTION
An Intrusion Detection System (IDS) analyzes network packets or host events to identify suspicious behavior, using signatures, heuristics, and anomaly detection. Network-based IDS sensors monitor traffic; host-based IDS monitors system logs, files, and processes. IDSs often integrate with SIEM for correlation and incident response workflows. Key challenges include tuning for false positives and keeping signatures current. IDS complements preventive controls, providing visibility into attempts and breaches.
ALTERNATIVE DEFINITIONS
CISA
Intrusion detection systems (IDS) monitor network traffic for suspicious activity and issue alerts when such activity is discovered.
Focuses on monitoring and alerting on suspicious network activity.
Wikipedia
An intrusion detection system (IDS) is a device or software application that monitors a network or systems for malicious activity or policy violations.
Highlights host and network monitoring scope.
RELATED TERMS
SIEM Network Firewall Endpoint Detection and Response Data Anomaly Detection Signature-Based Detection Host-based Intrusion Detection System Network-based Intrusion Detection System Threat Intelligence MITRE ATT&CK
COMPETING TERMS
KNOWLEDGE AREAS
Data Security Observability & Telemetry Infrastructure
TARGET AUDIENCE
Security Architect Cybersecurity Engineer Chief Information Security Officer IT Auditor DevOps Engineer IT Manager
EXTERNAL SOURCES
- Wikipedia - Intrusion detection system
- NIST - SP 800-94 guide on IDS/IPS
- CISA - Government overview of IDS concepts
- Suricata - Open-source IDS/IPS engine docs
- Snort - Snort IDS rules and docs
TOP QUESTIONS
What is an Intrusion Detection System and how does it work?
An IDS inspects network or host data for signs of attack or policy violations. It uses signatures and anomaly models to alert security teams for investigation.
Category: Basics
What is the difference between NIDS and HIDS in Intrusion Detection Systems?
NIDS monitors network traffic at strategic points; HIDS monitors activity on individual hosts. Many organizations deploy both for defense-in-depth.
Category: Comparison
How does an Intrusion Detection System differ from an Intrusion Prevention System?
IDS detects and alerts; IPS actively blocks in-line. IDS is out-of-band and less disruptive, useful where false positives must be minimized.
Category: Comparison
What are common IDS detection techniques?
Signature matching, anomaly detection, heuristic analysis, and protocol decoding are common. Hybrid systems combine techniques to reduce false positives.
Category: Technique
How should alerts from an Intrusion Detection System be managed?
Integrate with SIEM for correlation, prioritize by severity, and use playbooks for response. Continuous tuning reduces alert fatigue.
Category: Operations
What are typical IDS deployment locations?
Place sensors at network ingress/egress, DMZ, critical segments, and monitor key hosts. Mirror/SPAN ports and TAPs help visibility.
Category: Architecture
What is a common mistake when implementing an Intrusion Detection System?
Failing to tune signatures and baselines leads to excessive false positives. Ignoring encrypted traffic visibility is another oversight.
Category: Mistakes
How often should IDS signatures be updated?
Update continuously or at least daily in active environments. Rapid updates are essential during emerging threat campaigns.
Category: Management
Is an Intrusion Detection System still relevant with modern EDR and XDR?
Yes. IDS provides network-layer visibility that complements endpoint and extended detection. It remains a key SOC sensor.
Category: Relevancy