# Network Scan Nmap

> Run Nmap for network discovery and security auditing. Performs port scanning, service detection, OS fingerprinting, and vulnerability script scanning.

- Skill: `vchirrav-eng/network-scan-nmap` (Agent Skill)
- Install (CLI): `npx skillmds@latest add vchirrav-eng/network-scan-nmap`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vchirrav-eng/network-scan-nmap/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Product & Planning
- Author: vchirrav-eng (https://skillmd.com/u/vchirrav-eng)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vchirrav-eng/network-scan-nmap

---


# Network Scanning with Nmap

You are a security engineer performing network discovery and security auditing using **Nmap**.

## When to use

Use this skill when asked to scan network hosts for open ports, identify services, or check for network-level vulnerabilities.

## Prerequisites

- Nmap installed (`apt install nmap` or `brew install nmap`)
- Verify: `nmap --version`
- **Important:** Only scan hosts you have authorization to test.

## Instructions

1. **Identify the target** — Confirm the host(s) or network range to scan.
2. **Run the scan:**

   **Service detection:**
   ```bash
   nmap -sV -sC -oX nmap-results.xml <target>
   ```

   **Full port scan:**
   ```bash
   nmap -p- -sV -oX nmap-full-results.xml <target>
   ```

   **Vulnerability scripts:**
   ```bash
   nmap --script=vuln -oX nmap-vuln-results.xml <target>
   ```

   - Quick scan: `nmap -F -sV <target>`
   - UDP scan: `nmap -sU --top-ports 100 <target>`
   - Specific ports: `nmap -p 22,80,443,8080 -sV <target>`
   - Network range: `nmap -sn 192.168.1.0/24` (host discovery only)
   - XML to JSON: `nmap -oX - <target> | python3 -c "import xmltodict,json,sys; print(json.dumps(xmltodict.parse(sys.stdin.read())))"`

3. **Parse the results** — Present findings:

```
| # | Host | Port | State | Service | Version | Scripts/CVEs |
|---|------|------|-------|---------|---------|-------------|
```

4. **Summarize** — Provide:
   - Total hosts up, open ports found
   - Unexpected open ports (attack surface)
   - Outdated service versions with known CVEs
   - Recommendations: close unnecessary ports, update services, add firewall rules