License & Deployment Mix: 25 tools – 12 OSS, 0 SaaS. (OSS and SaaS counts can overlap when an open-source tool also offers a vendor-hosted edition.)

What Is IDS / IPS?

Intrusion Detection Systems (IDS) monitor network traffic and system activity for malicious behavior, policy violations, and known attack signatures. IDS operates passively – it observes, analyzes, and alerts but does not block traffic. When an IDS detects suspicious activity, it generates alerts for security analysts to investigate.

Intrusion Prevention Systems (IPS) extend IDS by adding inline enforcement – the ability to drop, reject, or modify malicious traffic in real time before it reaches its target. IPS sits in the network path (inline mode) and makes automated blocking decisions based on rules, signatures, and behavioral analysis.

Together, IDS/IPS forms a critical layer of network and host security that detects and (optionally) blocks attacks as they traverse the network or target individual hosts. IDS/IPS complements firewalls (which enforce access control policies) by performing deep packet inspection – analyzing packet payloads, protocol behavior, and traffic patterns to identify threats that firewall rules alone cannot catch.

Enterprise IDS/IPS platforms provide:

• Signature-based detection – matching network traffic against databases of known attack patterns (Emerging Threats, Snort rules, ET Pro rulesets); fast and accurate for known threats; low false positive rate when rules are well-tuned
• Anomaly-based detection – establishing baselines of normal network behavior and alerting on deviations; detects zero-day attacks and novel threats that signatures miss; higher false positive rate requires tuning
• Protocol analysis – deep inspection of application-layer protocols (HTTP, DNS, TLS, SMB, SSH) to detect protocol violations, tunneling, and evasion techniques
• Network traffic analysis – flow metadata extraction, connection tracking, file carving, and session reconstruction for forensic analysis and threat hunting
• Automated prevention – inline blocking of malicious traffic (IPS mode); TCP reset injection, packet dropping, and connection termination; rate limiting and traffic shaping for DDoS mitigation
• Threat intelligence integration – consuming external threat feeds (STIX/TAXII, MISP, abuse.ch) to enrich detection with current indicators of compromise (IoCs) and malicious IP/domain lists
• File extraction and analysis – extracting files from network streams for malware scanning (Yara rules, sandbox analysis); detecting malicious payloads in HTTP downloads, email attachments, and SMB file transfers
• Encrypted traffic inspection – TLS/SSL decryption for inline inspection (IPS mode); JA3/JA4 fingerprinting for detecting malicious TLS clients without decryption; certificate analysis for detecting C2 infrastructure
• Logging and alerting – structured alert output (EVE JSON, Unified2, syslog, CEF) for SIEM integration; network metadata logs for forensic analysis; PCAP capture for deep-dive investigation

IDS/IPS is foundational to network security. Without IDS, organizations have no visibility into malicious traffic traversing their networks. Without IPS, detected attacks must be manually blocked – too slow for fast-moving threats like worms, exploit attempts, and automated attack tools. Together, they provide the detection and enforcement layer between the firewall perimeter and endpoint security (EDR/XDR).

The information on these pages was researched by a combination of human review and large language models. To suggest an addition or correction, please contact us. Prepared by Rhodium Systems Inc., author of the ResorsIT platform — a unified IT operations management platform for IT teams and MSPs that integrates a curated suite of open-source, commercial, and SaaS applications into a single system with shared identity, single sign-on, access control, and a common audit trail. Use this catalogue only as a starting point for your own research, and review any tool carefully against your own requirements before relying on it. Catalogue data version 2026.197.

Comparison

This evaluation covers the full IDS/IPS landscape.

Overview Comparison

Open source leaders: Suricata (performance, multi-threaded), Zeek (protocol analysis, metadata), Snort (rule ecosystem, legacy), Security Onion (integrated platform)

Commercial leaders: Palo Alto NGFW (market share), Cisco NGIPS (enterprise), Darktrace (AI), Corelight (Zeek-based NDR)

Cloud-native: AWS Network Firewall (Suricata rules), Google Cloud IDS (Palo Alto engine), Azure Firewall IDPS

Detection Capabilities

Signature leaders: Suricata (largest compatible rule ecosystem – ET Open, ET Pro, Snort rules), Cisco NGIPS (Talos intelligence), Palo Alto (Threat Prevention + WildFire)

Anomaly / ML leaders: Darktrace (self-learning AI, no signatures required), Vectra AI (attack signal intelligence), ExtraHop (70+ protocols with ML)

Protocol analysis leaders: Zeek (deepest protocol parsing – 40+ analyzers), ExtraHop (70+ protocols), Suricata (comprehensive application- layer parsing)

Encrypted traffic leaders: Darktrace (ETA without decryption), Vectra AI (behavioral analysis of encrypted flows), Corelight (JA3/JA4 + ETA), Palo Alto (inline TLS decryption)

Deployment & Architecture

Best inline IPS: Suricata (DPDK for 40+ Gbps), Palo Alto NGFW (enterprise market leader), Cisco NGIPS (Talos intelligence)

Best passive IDS: Zeek (protocol metadata), Security Onion (integrated platform), Corelight (enterprise Zeek)

Best HA/clustering: Security Onion (distributed deployment), Zeek (native cluster architecture), CrowdSec (distributed agents)

Cloud-native: AWS Network Firewall, Google Cloud IDS, Azure Firewall IDPS (fully managed)

Integration Comparison

Best SIEM integration: Suricata (EVE JSON – industry standard), Zeek (richest metadata logs), Security Onion (built-in search), Corelight (enriched Zeek + Suricata)

Best API: CrowdSec (Local + Central REST API), OPNsense (full REST API), Cisco NGIPS (FMC API), Palo Alto (PAN-OS XML API)

OpenSearch/Elasticsearch native: Suricata (EVE JSON), Zeek (JSON output), Security Onion (built-in), Sagan (EVE-compatible)

SSO / OIDC Comparison

OIDC is the preferred SSO protocol. The table notes each tool’s behaviour with Authentik as the IdP.

* = requires extension, plugin, or specific configuration

Best SSO support: Darktrace (OIDC, SAML, SCIM), Vectra AI (OIDC, SAML, SCIM), Corelight (OIDC, SAML, SCIM), cloud services (IAM-integrated)

No SSO: Most OSS IDS tools (Suricata, Snort, Zeek, OSSEC, Fail2Ban, AIDE) are CLI-based; SSO is provided by management platforms (Security Onion, OPNsense) or SIEM consoles

Monitoring Integration

Monitoring-stack integration for IDS/IPS platform health and alert monitoring, using a Telegraf / Fluent Bit / Grafana pipeline.

Best monitoring integration: Suricata (native Telegraf plugin, EVE JSON for Fluent Bit, official Grafana dashboards), CrowdSec (Prometheus metrics, official Grafana dashboard), Security Onion (built-in monitoring)

Easiest log ingestion: Suricata EVE JSON, Zeek JSON, Sagan EVE JSON (all structured JSON directly parseable by Fluent Bit)

Performance & Scale

Highest throughput (OSS): Suricata with DPDK (40+ Gbps), Zeek cluster (40+ Gbps with worker scaling)

Highest throughput (commercial): Palo Alto NGFW (100 Gbps), Corelight (100 Gbps sensors), Darktrace / Vectra (enterprise-scale AI)

Best multi-tenancy: Cloud services (native multi-account/project), CrowdSec (organizations), Security Onion (distributed SOC)

Tools

25 tools.

AIDE

AIDE (Advanced Intrusion Detection Environment) is an open-source file integrity monitoring (FIM) tool that creates a database of file attributes and periodically checks files against this baseline to detect unauthorized modifications.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

AWS Network Firewall

AWS Network Firewall is a managed network firewall and IDS/IPS service that uses Suricata as the underlying detection engine.

License: Proprietary (proprietary) · Kind: web · Deploy: saas, native · SSO: none

Website

Azure Firewall IDPS

Azure Firewall IDPS is a signature-based intrusion detection and prevention system built into Azure Firewall Premium SKU.

License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none

Website

Cisco Secure IPS / Firepower

Cisco Secure IPS (formerly Firepower NGIPS) is a commercial next-generation intrusion prevention system built on the Snort detection engine and managed through Firepower Management Center (FMC).

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Corelight

Corelight is a commercial network detection and response (NDR) platform built on Zeek, the open- source network analysis framework.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

CrowdSec

CrowdSec is an open-source, crowdsourced intrusion prevention system that analyzes visitor behavior and provides an automated response by leveraging community-driven threat intelligence.

License: MIT (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Darktrace

Darktrace is a commercial network detection and response (NDR) platform that uses unsupervised machine learning to model normal network behavior and detect anomalies indicating cyber threats.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

ExtraHop

ExtraHop is a commercial network detection and response (NDR) platform that analyzes network traffic in real-time using wire data analytics and machine learning.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Fail2Ban

Fail2Ban is an open-source intrusion prevention framework that monitors log files for malicious patterns and automatically bans offending IP addresses by updating firewall rules.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Google Cloud IDS

Google Cloud IDS is a managed intrusion detection service that provides network-based threat detection for Google Cloud workloads.

License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none

Website

Hillstone NIPS

Hillstone Networks NIPS (Network Intrusion Prevention System) is a commercial inline IPS appliance designed for high-performance threat detection and prevention.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Kismet

Kismet is an open-source wireless network detector, sniffer, wardriving tool, and wireless intrusion detection system (WIDS).

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

OPNsense IDS/IPS

OPNsense is an open-source firewall and routing platform based on FreeBSD that includes an integrated IDS/IPS powered by Suricata.

License: BSD-2-Clause (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

OSSEC

OSSEC is an open-source host-based intrusion detection system that provides log analysis, file integrity monitoring (FIM), rootkit detection, real-time alerting, and active response.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Palo Alto Networks NGFW

Palo Alto Networks next-generation firewall (NGFW) provides integrated IDS/IPS as part of its Threat Prevention subscription service.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Sagan

Sagan is an open-source, multi-threaded log analysis engine that uses Snort/Suricata-style rules to detect threats in log data.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Samhain

Samhain is an open-source host-based intrusion detection system providing file integrity monitoring, log file monitoring, rootkit detection, port monitoring, and rogue SUID/SGID detection.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Security Onion

Security Onion is a free, open-source Linux distribution purpose-built for network security monitoring (NSM), intrusion detection, enterprise security monitoring, and log management.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Snort 3

Snort is the original open-source network intrusion detection and prevention system, first released in 1998 by Martin Roesch.

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

Stamus Networks

Stamus Networks provides a commercial network detection and response (NDR) platform built on Suricata.

License: Proprietary (proprietary) · Kind: web · Deploy: native, appliance · SSO: none

Website

Suricata

Suricata is a high-performance, open-source network intrusion detection and prevention system developed by the Open Information Security Foundation (OISF).

License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source

TippingPoint

TippingPoint is a commercial next-generation intrusion prevention system owned by Trend Micro, known for its purpose-built hardware with ASIC- based packet processing for wire-speed inline inspection.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Trellix IPS

Trellix IPS (formerly McAfee Network Security Platform / NSP) is a commercial network intrusion prevention system that provides signature-based and behavioral detection using purpose-built hardware appliances and virtual sensors.

License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none

Website

Vectra AI

Vectra AI is a commercial network detection and response (NDR) platform that uses AI to detect and prioritize real attacks across cloud, data center, and enterprise networks.

License: Proprietary (proprietary) · Kind: web · Deploy: saas, docker, native, appliance · SSO: none

Website

Zeek (formerly Bro)

Zeek is an open-source network analysis framework that passively monitors network traffic to produce detailed protocol logs, detect anomalies, and extract metadata.

License: BSD-3-Clause (OSS) · Kind: web · Deploy: native · SSO: none

Website · Source