What is a network security assessment?

A network security assessment is a structured evaluation of your IT network infrastructure to identify vulnerabilities, misconfigurations, and security gaps. It typically covers perimeter defences, identity and access controls, endpoint protection, data backup, and security awareness — producing a scored report with prioritised remediation recommendations.

How long does the VP Audit assessment take?

The VP Audit assessment takes approximately 5 minutes. You answer 15 targeted questions across 5 security domains. Once complete, your scored report is generated instantly — no waiting, no account required.

Is VP Audit free to use?

Yes. VP Audit is completely free. There is no account, subscription, or payment required. Your answers never leave your browser — the scoring happens entirely client-side.

What security domains does VP Audit cover?

VP Audit covers five security domains: Perimeter & Connectivity (firewall, VPN, remote access), Identity & Access Management (passwords, MFA, privilege), Endpoint Security (patching, AV, MDM), Data & Backup (backup frequency, encryption, recovery testing), and Awareness & Response (staff training, incident response, phishing).

Can I export my security assessment results?

Yes. VP Audit generates a personalised PDF report with your organisation name, score breakdown, findings by severity, and remediation recommendations. The PDF is generated in your browser and can be downloaded immediately.

Tools

Free Network Security Audit Tools — What Actually Works in 2026

3 May 2026 · 7 min read · VantagePoint Networks

Free network security audit tools range from powerful technical scanners to structured assessment frameworks. The right tool depends on your technical expertise: Nmap and Nessus Essentials are excellent for engineers who can interpret raw scan output; guided assessment tools like VP Audit are better for IT generalists and business owners who need scored, actionable results without deep security knowledge. This guide gives an honest assessment of what each free tool does well and where it falls short.

⚠ Important: Only scan networks you own or have written permission to scan

Scanning networks without authorisation is illegal in the UK under the Computer Misuse Act 1990. Always ensure you have explicit written permission before running any scan tool against infrastructure.

Free Network Security Audit Tools Compared

Nmap

Network Discovery & Port Scanning

FREEMedium difficulty

Best for: Discovering all devices on your network and identifying open ports and running services

Limitations: Command-line interface; requires interpretation; does not assess configuration quality — only reports what is open

nmap -sn 192.168.1.0/24 (host discovery)

nmap -sV -p 1-1024 192.168.1.1 (service detection)

Verdict: Essential starting point for any network audit. Every IT team should know basic Nmap commands.

Nessus Essentials

Vulnerability Scanner

FREE (Free up to 16 IPs)Medium difficulty

Best for: Automated vulnerability scanning with CVE identification and severity ratings

Limitations: 16 IP limit on free tier. Tenable account required. Scans take time and generate large reports that need interpretation.

Verdict: Best free option for vulnerability scanning. The 16 IP limit is workable for most SMBs who want to scan their server infrastructure.

OpenVAS / Greenbone

Vulnerability Scanner

FREEHigh difficulty

Best for: Full-feature vulnerability scanning with no IP limit

Limitations: Complex setup (Docker or dedicated VM required). Community feed has a delay vs. paid Greenbone Enterprise. Significant resource requirements.

Verdict: Powerful but difficult to set up. Appropriate for IT teams with Linux knowledge. Not recommended for non-technical users.

Wireshark

Network Traffic Analysis

FREEHigh difficulty

Best for: Analysing network traffic to identify unusual protocols, rogue devices, or data exfiltration patterns

Limitations: Requires deep networking knowledge to interpret captures. Not a vulnerability scanner — shows traffic, not vulnerabilities.

Verdict: Expert-level tool. Useful for incident investigation and verifying segmentation. Not suitable for a first-time security audit.

Shodan

External Attack Surface

FREE (Free tier: limited queries)Low difficulty

Best for: Seeing what your internet-facing infrastructure looks like to an attacker — exposed ports, banners, and known vulnerabilities

Limitations: Only shows internet-facing assets. Does not assess internal network. Free tier has limited results.

Verdict: High-value, low-effort first check. Search for your public IP ranges and see exactly what attackers see.

VP Audit

Guided Assessment

FREELow difficulty

Best for: SMBs without dedicated security staff who need a structured, scored assessment across all 5 security domains — not just network scanning

Limitations: Assessment-based rather than technical scan. Does not discover vulnerabilities programmatically — relies on answering questions accurately.

Verdict: Best starting point for non-technical users and SMBs. Covers perimeter, identity, endpoints, backup, and awareness in a structured format with scored output.

Which Tool Should You Start With?

If you are…	Start with
Business owner with no dedicated IT	VP Audit — structured, no technical knowledge required
IT generalist wanting a quick overview	VP Audit, then Shodan to check external exposure
IT manager wanting technical detail	Nmap for discovery, Nessus Essentials for vulnerability scanning
Security professional doing a full audit	Nmap + Nessus/OpenVAS + Wireshark + manual config review
Anyone, before anything else	Shodan — takes 5 minutes to see your external attack surface

Frequently Asked Questions

What is the best free network security scanning tool?

Nmap is the most widely used free network scanning tool for discovery and port scanning. For vulnerability assessment, Nessus Essentials (free for up to 16 IPs) and OpenVAS are the most capable free options. For SMBs without technical expertise, a guided assessment tool like VP Audit provides the accessibility of a checklist with structured scoring.

Is Nmap safe to use on your own network?

Yes. Nmap is safe to use on networks you own or have explicit written permission to scan. Scanning networks without authorisation is illegal in the UK under the Computer Misuse Act 1990. Always get written authorisation before scanning any network you do not own.

Start With the Simplest Free Tool

VP Audit takes 5 minutes, requires no technical knowledge, and gives you a scored report across all 5 security domains. No install required.

Start Free Assessment →

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