As a cost-conscious organization, which open-source security tools are viable substitutes for commercial products in a small environment?

For a cost-conscious small organization, open-source security tools provide incredible capability without the enterprise price tag. The key is picking tools that offer strong community backing, active maintenance, and manageable administrative overhead so your team doesn't drown in maintenance.

Here is a curated lineup of viable, high-impact open-source substitutes for common commercial security categories:

• SIEM & Log Management (Substitute for Splunk / Datadog): Wazuh or ELK Stack (Elasticsearch, Logstash, Kibana) . Wazuh is an open-source XDR and SIEM platform that handles log analysis, integrity monitoring, intrusion detection, and cloud security posture out of the box with an easier setup than a raw ELK stack.
• Vulnerability Scanning (Substitute for Tenable Nessus / Qualys): OpenVAS (Greenbone Vulnerability Management) . A full-featured vulnerability scanner that regularly updates its network vulnerability tests (NVTs) to catch missing patches and misconfigurations.
• Endpoint Detection & Response - EDR (Substitute for CrowdStrike / SentinelOne): Wazuh Agent or LimaCharlie (free tier/open core components). While true open-source EDR is hard, Wazuh provides robust host-based monitoring, rootkit detection, and active response capabilities.
• Network Monitoring & IDS (Substitute for Darktrace / ExtraHop): Suricata or Zeek . Both are high-performance network intrusion detection and security monitoring engines that give you deep visibility into network traffic anomalies.
• Identity & Access Management - IAM (Substitute for Okta / Ping Identity): Keycloak . An open-source identity and access management solution backed by Red Hat that supports OpenID Connect, OAuth 2.0, and SAML 2.0 protocols for securing applications.
• Secret Management & Vault (Substitute for CyberArk / HashiCorp Vault): Bitwarden Secrets Manager (self-hosted/open-source components) or Infisical . Great for keeping API keys and credentials out of plain text configuration files.

Would you like to explore deployment requirements (hardware/sizing) for one of these tools, or do you have a specific security gap you want to prioritize first?

Yes. For a small environment, open-source security tools can replace a surprising amount of commercial functionality—but the main tradeoff is that you replace license cost with deployment, maintenance, tuning, and expertise.

Practical shortlist

If I were building a small organization's stack

I'd avoid trying to assemble 20 different tools. A cost-conscious baseline could be:

1. Wazuh — central security monitoring, endpoint agents, log collection, file-integrity monitoring, vulnerability detection and response. Wazuh is explicitly free/open source and combines SIEM/XDR capabilities.
2. OpenVAS — scheduled vulnerability scanning of servers and network devices. The scanner supports both authenticated and unauthenticated testing and receives regularly updated vulnerability tests.
3. Suricata — network intrusion detection/prevention where network visibility is important.
4. Nmap — asset discovery and basic network reconnaissance.
5. OWASP ZAP — automated web-application security testing. OWASP maintains a broad catalog of free/open-source DAST tools, including ZAP-related tooling.
6. Trivy + Gitleaks — inexpensive vulnerability and secrets scanning in development/CI.
7. Prowler — cloud configuration/security assessment if you use AWS, Azure, GCP or Kubernetes; OWASP's vulnerability-tool catalog lists it as open source.

The particularly strong substitutions

Wazuh → SIEM/EDR: Probably the most compelling option for a small organization. It provides endpoint agents, centralized logging, detection, file-integrity monitoring, vulnerability detection, configuration assessment and incident-response capabilities in one platform.

OpenVAS → Nessus/Qualys: A very reasonable choice when you mainly need recurring vulnerability assessments rather than a highly polished enterprise vulnerability-management platform. Greenbone describes OpenVAS as a full-featured vulnerability scanner with authenticated and unauthenticated testing and continuously updated tests.

ZAP → Burp Suite Pro/commercial DAST: Particularly attractive if you have one or two web applications and can accept more manual testing. OWASP specifically maintains lists of open-source and free application-security tooling.

Where I'd not automatically replace the commercial product

The biggest mistake is assuming "open source = equivalent."

Commercial products often buy you:

• 24/7 vendor support
• managed detection and response
• polished dashboards and reporting
• automatic rule/content updates
• integration with identity, ticketing and cloud platforms
• behavioral/AI detection
• incident-response automation
• compliance reporting
• someone else operating the infrastructure

For a 5–50 person organization with a capable IT/security administrator, open source can be extremely cost-effective. For a small organization with no security expertise, a managed commercial service may actually have a lower total cost despite the license fee.

A sensible cost-conscious architecture

I'd prioritize coverage over tool count:

Endpoints → Wazuh → centralized alerts Network → Suricata → Wazuh/Security Onion Infrastructure → OpenVAS Applications → ZAP + Trivy + Gitleaks Cloud → Prowler Investigation → Velociraptor/osquery

That gives a small team coverage across endpoint, network, vulnerability, application, cloud and incident-response domains without buying a separate commercial platform for each.

The important caveat is that "free software" doesn't mean zero cost: storage, VMs, backups, updates, rule tuning and administrator time become your responsibility. Current comparisons similarly identify operational effort and support as the major tradeoff for open-source security stacks.

If you tell me roughly how many endpoints, servers, network devices, and cloud workloads you have, I can narrow this down to a minimal 3–5-tool stack and map each one directly against products such as Microsoft Defender, CrowdStrike, Sentinel, Nessus, Qualys, and Splunk.

Yes. For a small environment, open-source security tools can replace a surprising amount of commercial functionality—but the trade-off is usually staff time and operational complexity rather than license cost.

Practical open-source substitutes

My shortlist for a small organization

1. Wazuh — the best "one platform" choice. Wazuh combines SIEM and XDR functions with endpoint agents, vulnerability detection, configuration assessment, file-integrity monitoring, log analysis and automated response. It is genuinely free/open source, rather than merely a free trial.

That makes it particularly compelling if you currently pay for several products such as endpoint monitoring + SIEM + vulnerability visibility. The catch is that someone still has to deploy it, tune detections, investigate alerts and maintain the infrastructure.

2. Suricata — excellent replacement for a standalone IDS/IPS. Suricata is a high-performance network IDS/IPS and network-security-monitoring engine, licensed GPLv2 and maintained by the nonprofit Open Information Security Foundation.

It's especially useful when paired with an open-source firewall such as OPNsense rather than deployed as an isolated project.

3. Greenbone Community Edition — good vulnerability-scanning substitute. The Greenbone Community Edition is the open-source successor/framework around OpenVAS and provides vulnerability scanning and management capabilities.

For a small internal network, this can be a reasonable alternative to paying for a full commercial vulnerability-management platform. Be aware that the community edition and commercial Greenbone offerings differ in feeds and features.

4. Zeek — choose it when visibility matters more than simplicity. Zeek is superb for understanding what's happening on your network, but it isn't a drop-in "install it and forget it" IDS. It tends to make more sense when you have someone comfortable analyzing network telemetry.

5. CrowdSec — inexpensive defense-in-depth. CrowdSec is particularly interesting for internet-facing services: it can analyze behavior and coordinate blocking decisions. I'd view it as a complement to Wazuh/firewall controls rather than a replacement for an endpoint security platform.

A sensible low-cost stack

For, say, 10–100 endpoints and a modest number of servers, I'd lean toward:

Firewall: OPNsense/pfSense ↓ Network detection: Suricata ↓ Endpoint + SIEM: Wazuh ↓ Vulnerability scanning: Greenbone Community Edition ↓ Optional internet-facing protection: CrowdSec

That gives you coverage across firewalling → network detection → endpoint telemetry → centralized security monitoring → vulnerability management without paying per-endpoint SIEM/EDR licensing.

The important caveat is that "free software" doesn't mean free security operations. Commercial products often bundle threat intelligence, managed detection, automatic tuning, support, cloud infrastructure and analysts. Wazuh, for example, can be self-hosted or deployed in a managed cloud offering; its self-hosted architecture requires you to operate the server, indexer and dashboard yourself.

If you're extremely cost-conscious, I'd start with Wazuh + your existing firewall, then add Greenbone and Suricata only where there's a demonstrated gap. That avoids building a six-tool security stack that becomes a full-time job.

For a cost-conscious small organization, open-source security tools provide robust, enterprise-grade capabilities without the steep licensing fees. Here is a curated list of viable open-source substitutes categorized by security domain:

• Vulnerability Assessment and Scanning: OpenVAS (Greenbone) serves as a powerful substitute for commercial vulnerability scanners like Tenable Nessus or Qualys, offering comprehensive network vulnerability testing and compliance auditing.
• Security Information and Event Management (SIEM): Wazuh or Elastic SIEM (ELK Stack) act as strong alternatives to commercial SIEMs like Splunk or Datadog, providing log analysis, integrity monitoring, and threat detection.
• Endpoint Detection and Response (EDR): Wazuh (which includes robust endpoint monitoring capabilities) or LimaCharlie (which offers a generous free tier and open-source underpinnings) can substitute for heavy commercial EDR agents like CrowdStrike or SentinelOne.
• Network Intrusion Detection/Prevention (NIDS): Suricata or Snort replace expensive commercial firewalls/IDS appliances by providing real-time traffic analysis and packet logging.
• Identity and Access Management (IAM) / Single Sign-On (SSO): Keycloak is an open-source alternative to Okta or Microsoft Entra ID, handling user federation, identity brokering, and fine-grained authorization.
• Web Application Firewall (WAF): ModSecurity paired with an Nginx or Apache reverse proxy provides robust application-layer protection, substituting for cloud WAF solutions like Cloudflare Enterprise or Imperva.
• Penetration Testing and Scanning: OWASP ZAP (Zed Attack Proxy) substitutes for commercial application scanners like Burp Suite Professional, automating vulnerability finding in web applications during development.

To help narrow down what fits your infrastructure best, let me know:

• What is your primary environment (cloud-heavy like AWS/Azure, on-premise, or hybrid)?
• Do you have dedicated IT/security staff to manage these tools, or do you need options focused on ease of maintenance?

Open-source security tools can fully replace expensive commercial software in small environments, cutting licensing costs while maintaining strong defense layers. Smaller networks benefit from open-source because they have less data traffic, making deployment and management highly manageable without premium enterprise infrastructure.

🛡️ Firewall & Network Security

• OPNsense : A powerful routing and firewall platform that serves as an excellent substitute for commercial appliances like Fortinet FortiGate or SonicWall. It features a modern, user-friendly web interface, weekly security updates, and built-in support for two-factor authentication.
• pfSense Community Edition : A highly reliable, long-standing firewall option that directly replaces mid-tier commercial hardware firewalls. It provides robust packet filtering, virtual private networking (VPN) capabilities, and extensive documentation for small IT teams.

🔎 Network Monitoring & Intrusion Detection

• Zeek : A powerful network analysis framework that replaces commercial Network Detection and Response (NDR) platforms. It translates raw packets into structured, searchable logs focused on behavioral analysis rather than just static signatures.
• Suricata : A high-performance Intrusion Detection System (IDS) and Intrusion Prevention System (IPS) that acts as a viable alternative to Cisco Firepower. It scans network traffic in real-time to automatically log and block known malicious threats.

💻 Endpoint Detection & Response (EDR)

• Wazuh : A comprehensive security monitoring platform that effectively replaces commercial EDRs and SIEMs like Splunk or CrowdStrike Falcon. It monitors endpoint behavior, detects vulnerabilities, checks for compliance, and triggers automated responses to threats.
• Velociraptor : An advanced endpoint monitoring and digital forensics tool that substitutes for expensive incident response software. It allows small teams to precisely query and hunt for malicious activity across all company laptops and servers simultaneously.

📊 Vulnerability Management

• Greenbone Community Edition : An open-source vulnerability scanner built on the OpenVAS framework, serving as a direct alternative to Tenable Nessus or Rapid7 InsightVM. It regularly updates its threat database to identify missing security patches and system misconfigurations.

⚠️ Hidden Costs & Core Trade-offs

While open-source tools save money on software licenses, cost-conscious organizations must plan for these operational realities:

• Internal Labor : You trade financial capital for human capital. Your team will spend more time manually configuring, tuning, and updating these systems compared to "plug-and-play" commercial tools.
• Hardware Requirements : These tools require dedicated physical servers or cloud virtual machines to run, meaning you must budget for underlying infrastructure costs.
• Lack of Formal Support : There is no vendor phone number to call during a breach. Your team must rely on community forums, documentation, and internal expertise for troubleshooting.

To help narrow this down for your specific setup, what operating systems do your endpoints use, and how many total devices are you protecting?

Yes. For a small environment with limited security budget and IT staff, several mature open-source tools can replace substantial portions of commercial security suites. The main trade-off is that you exchange license fees for deployment, tuning, maintenance, and expertise.

Strong candidates

My shortlist for a small organization

1. Wazuh — best overall starting point

Wazuh is probably the most compelling substitute if you want one platform covering a lot of ground. It provides SIEM/XDR functionality, endpoint agents, log collection, vulnerability detection, file-integrity monitoring, configuration assessment, malware detection and automated response. It is explicitly free/open source and supports a single-server deployment for smaller environments.

Commercial replacement: portions of an EDR + SIEM + compliance-monitoring stack.

Caveat: Don't assume "free" means zero operational cost. You'll need someone to maintain the server, tune alerts and investigate them.

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2. Suricata — inexpensive network IDS/IPS

Suricata is a mature open-source IDS/IPS and network security engine. It is GPLv2 and maintained by the nonprofit Open Information Security Foundation.

It is particularly attractive if you already have a firewall capable of running or forwarding traffic to Suricata. For a small network, it can provide useful network threat detection without buying a dedicated security appliance.

Commercial replacement: network IDS/IPS functionality.

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3. Zeek — excellent network visibility

Zeek takes a different approach from Suricata. Rather than primarily blocking attacks, it passively analyzes network traffic and produces detailed, high-fidelity logs. It can show things such as connections, DNS activity, HTTP behavior and other application-layer activity.

It's especially useful when investigating an incident and asking, "What actually happened on this network?"

Commercial replacement: network security monitoring/NDR functionality.

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4. Greenbone Community Edition — vulnerability management

Greenbone Community Edition contains the open-source software behind the OpenVAS vulnerability-management stack. Its scanner uses continuously updated vulnerability tests.

Commercial replacement: much of what organizations use Nessus/Tenable-type products for.

The important distinction is that vulnerability scanning isn't the same thing as vulnerability management. Commercial products may provide better reporting, prioritization, asset management and support.

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A cost-effective small-environment stack

If I were designing a 10–100 endpoint environment on a tight budget, I'd consider:

Endpoints → Wazuh → centralized security monitoring
Network → Suricata → network IDS/IPS
Network visibility → Zeek (optional)
Monthly/weekly scanning → Greenbone/OpenVAS
Troubleshooting → Wireshark

That gives you a surprisingly broad security capability without recurring per-endpoint SIEM/EDR licensing.

Where I wouldn't replace commercial tooling blindly

Open source becomes less attractive when you need:

• 24/7 managed detection and response
• guaranteed vendor support/SLA
• highly polished compliance reporting
• automatic cloud/SaaS integrations
• sophisticated EDR behavioral detection
• a security team with little time for tuning and maintenance

In those cases, a hybrid approach is often cheaper overall: use open-source tools for logging, vulnerability scanning and network visibility, while paying for managed EDR/MDR where the organization lacks security expertise.

Bottom line: For a genuinely small organization, I'd start with Wazuh + Suricata + Greenbone, adding Zeek if network visibility is important. Wazuh is the strongest "commercial-suite substitute" of the group because it covers multiple security functions rather than just one.

For a cost-conscious small environment, leveraging open-source security tools can provide robust defense-in-depth without the enterprise price tag. Here is a curated list of viable open-source substitutes for major commercial security categories:

• Vulnerability Scanning: OpenVAS (Greenbone) serves as a robust substitute for commercial vulnerability scanners like Tenable Nessus or Qualys, offering comprehensive network vulnerability testing and regular feed updates.
• Security Information and Event Management (SIEM): Wazuh or Elastic Stack (ELK) act as strong alternatives to commercial SIEMs like Splunk or Datadog, providing log management, file integrity monitoring, and threat detection.
• Endpoint Detection and Response (EDR): LimaCharlie (open/free tiers available for small setups) or Wazuh (with its integrated agent capabilities) provide foundational endpoint visibility, behavioral monitoring, and response capabilities comparable to CrowdStrike or Microsoft Defender for Endpoint.
• Network Intrusion Detection (NIDS): Suricata or Snort function as high-performance alternatives to commercial IDS/IPS appliances, inspecting network traffic for malicious signatures and anomalies.
• Web Application Firewall (WAF): ModSecurity (paired with Nginx or Apache) offers a viable open-source alternative to commercial cloud WAFs like Cloudflare or Akamai for protecting internal or self-hosted web applications.
• Identity and Access Management (IAM): Keycloak provides comprehensive single sign-on (SSO), identity federation, and user management as an open-source alternative to Okta or Ping Identity.
• Network Scanning and Reconnaissance: Nmap remains the industry standard for network discovery and port scanning, matching or exceeding the utility of many commercial asset-discovery tools.

Would you like me to focus on setting up a specific category, or would you prefer a recommendation on hardware sizing and resource requirements for deploying these in a small team?

Yes. For a small environment, several open-source tools can replace substantial portions of commercial security stacks—provided you are willing to trade some convenience, vendor support, and automation for lower licensing costs and more hands-on administration.

The strongest choices

1. Wazuh — best overall starting point

If you only deploy one major security platform, I'd start here. Wazuh combines SIEM and XDR capabilities, with agents that provide endpoint telemetry, file-integrity monitoring, configuration assessment, vulnerability detection, malware detection, and response capabilities. It is free/open source and can be deployed with a single central server for a small environment.

It can realistically replace a number of separate products in a small organization, although it won't provide the same turnkey experience as a commercial MDR/EDR service.

2. Suricata — inexpensive network detection

Suricata is a high-performance open-source IDS/IPS and network-security-monitoring engine. It's particularly attractive if you already have a firewall capable of mirroring or passing traffic to a monitoring sensor.

A small organization could run it on a modest dedicated VM or appliance and feed alerts into Wazuh.

3. Greenbone Community Edition/OpenVAS — vulnerability management

Greenbone Community Edition provides the open-source vulnerability-management stack commonly associated with OpenVAS. It includes scanning, vulnerability management, reporting, and a web interface.

This is a good candidate for replacing a paid vulnerability scanner when your environment is small and you don't need a highly polished SaaS workflow.

A sensible low-cost stack

For, say, 20–100 endpoints, I would consider:

Wazuh + Suricata + Greenbone

• Wazuh: endpoint monitoring, centralized logs, FIM, configuration assessment, vulnerability visibility and alerting.
• Suricata: network IDS/IPS.
• Greenbone: periodic authenticated vulnerability scans.
• Existing firewall:** perimeter protection.
• Existing OS security controls:** Windows Defender, Linux security mechanisms, patch management, MFA, backups, etc.

The important point is that open source doesn't mean zero cost. You're eliminating or reducing license/subscription costs, but you take on server infrastructure, upgrades, tuning, backups, alert triage, and incident-response expertise yourself. Wazuh, for example, has multiple central components—server, indexer and dashboard—although its documentation supports a single-host deployment for getting started.

Where I would not replace commercial tooling

For a very small organization with no security staff, replacing a commercial EDR/MDR service entirely with DIY open source can be a false economy. A commercial provider may be worth paying for because you're buying 24/7 monitoring, threat hunting, response expertise and someone else maintaining the detection infrastructure, not merely software.

So my cost-conscious approach would be:

Open-source the tooling where practical; outsource the expertise where necessary.

For example, Wazuh + Suricata + Greenbone can provide a strong technical foundation, while an inexpensive managed SOC/MDR service handles the alerts that your small IT team doesn't have the capacity to investigate.

If you tell me roughly how many endpoints, servers, network devices, and cloud workloads you have, I can narrow this down to a realistic small-environment stack and estimate the infrastructure/administrative burden.

For a cost-conscious, small environment, mature open-source alternatives can effectively replace expensive commercial tools like CrowdStrike, Splunk, Tenable, and Palo Alto . The top viable open-source security tools categorized by function include Wazuh for SIEM/EDR, Greenbone OpenVAS for vulnerability management, Suricata for network monitoring, and OWASP ZAP for application security.

Core Open-Source Security Substitutes

• Wazuh (SIEM, XDR & Log Management): Replaces commercial platforms like Splunk or Datadog for log aggregation, while providing host-based intrusion detection (HIDS), file integrity monitoring, and basic endpoint telemetry.
• Greenbone OpenVAS (Vulnerability Scanner): Replaces commercial network scanners like Tenable Nessus or Rapid7 InsightVM by delivering comprehensive internal and external vulnerability assessments.
• Suricata or Snort (IDS/IPS): Replaces commercial network intrusion systems to perform real-time traffic analysis and block malicious packets on the wire.
• OWASP ZAP (DAST): Replaces expensive commercial web application scanners to find vulnerabilities in custom web apps during development.
• pfSense (Firewall/Router): Replaces commercial hardware-software firewall bundles (like enterprise Fortinet or Palo Alto units) for smaller office perimeters.
• TheHive (Incident Response): Replaces commercial case management and SOC coordination platforms, integrating smoothly with feeds like MISP.

Open-Source vs. Commercial Comparison for Small Teams

If you'd like, let me know:

• Your current infrastructure (cloud, on-prem, or hybrid)
• Your team size / available IT bandwidth for self-hosting and tuning

I can help you prioritize a lean, phased rollout plan for these tools.

Yes. For a small environment, you can replace a surprising amount of commercial security tooling with open-source software—but the tradeoff is usually staff time and operational complexity rather than license cost.

Practical open-source substitutes

My recommended small-environment stack

If I were trying to minimize both cash cost and administrative burden, I'd start with:

1. Wazuh — central security monitoring

Wazuh combines SIEM/XDR functionality with endpoint agents, configuration assessment, file-integrity monitoring, vulnerability detection, log analysis and incident response.

It is probably the closest thing to a general-purpose open-source substitute for a commercial SIEM/endpoint-monitoring stack. The important caveat is that you still have to tune rules, investigate alerts and maintain the infrastructure—"free" doesn't mean zero operational cost.

2. Greenbone/OpenVAS — vulnerability management

Greenbone Community Edition provides the open-source scanner, vulnerability-management daemon and web interface.

For a small network, this is a particularly sensible substitute for paying for a full Tenable/Qualys deployment. It won't necessarily match commercial products in detection coverage, prioritization and polish, so I'd treat it as risk identification, not proof that you've found every vulnerability. Community feedback also highlights the maintenance burden and occasional coverage differences versus commercial scanners.

3. Suricata — network intrusion detection

Put Suricata on a network tap/SPAN/mirror port if you actually need network-level detection. For a very small office, though, don't deploy it simply because you can: someone needs to review the resulting alerts.

4. Nmap — asset discovery

Use Nmap to periodically establish what's actually on the network and what services are exposed. This is one of the easiest ways to get significant security value for essentially no licensing cost.

5. Wireshark — investigation

Keep Wireshark available for incident investigation and troubleshooting. It complements rather than replaces the monitoring tools.

When Security Onion makes sense

Security Onion Solutions Security Onion is attractive if you want a more integrated network-security-monitoring platform. It bundles technologies including Suricata, Zeek and Wazuh into a broader detection environment.

For a very small organization, however, I'd generally choose Wazuh first rather than immediately deploying Security Onion. Security Onion is powerful, but the additional network telemetry creates additional infrastructure and alert-management requirements.

What I wouldn't try to replace entirely

There are areas where "open source = commercial equivalent" is misleading:

• EDR: Wazuh/osquery can provide substantial visibility, but a mature commercial EDR generally has stronger behavioral detection, automated response, threat intelligence and vendor support.
• Vulnerability management: OpenVAS is useful, but commercial scanners can have better coverage, prioritization, asset intelligence and reporting.
• 24×7 SOC/MDR: Software doesn't replace an analyst. If nobody is watching alerts at 2 a.m., a commercial MDR service may actually provide more security value than assembling a large free stack.
• Email/cloud security: If your organization lives in Microsoft 365 or Google Workspace, the security capabilities already included in those platforms may be more practical than building an open-source replacement.
• Compliance/reporting: Open-source tools can collect the evidence, but commercial products often save considerable time turning it into dashboards, audit trails and reports.

A sensible cost-conscious architecture

For perhaps dozens to a few hundred endpoints, I'd consider:

Endpoints → Wazuh agents → Wazuh server → alerts/dashboard

and separately:

Network → Suricata → Wazuh/Security Onion

plus:

Scheduled scans → Greenbone/OpenVAS

and:

Investigation → Nmap + Wireshark + Velociraptor/osquery

That gives you endpoint monitoring + centralized logging + vulnerability scanning + network detection + investigation capabilities without paying per-user/per-endpoint licenses.

The biggest mistake would be installing all of these at once. For a small IT/security team, Wazuh + Greenbone + Nmap is a much more manageable starting point. Add Suricata/Zeek only when you have a defined need and someone who can act on the alerts.

The broader lesson from small-team deployments is that the limiting resource tends to become people and tuning, not software licenses.