Docs · Tools
Port Scanner
The Port Scanner finds which doors a host has open — the ports, the services listening on them, their versions, and often the operating system. It wraps Nmap with seven one-click modes so you pick intent, not flags.
- Category
- Recon & Scan
- Powered by
nmap- Edition
- Free
- Where
- Desktop → Port Scanner tab
What it does
A port scan is the first question of almost every assessment: what is this host running? Nexus sends probes to a target and reports the open TCP/UDP ports, the service and version on each, and — in the OS-aware modes — a best-guess operating system. Results are saved to your scan history so other modules (Asset Inventory, Security Score, Scan Diff) can reuse them.
How to use it
192.168.1.0/24) in the target field. Inputs are sanitized before they ever reach Nmap.The seven modes
- Quick — top common ports, fastest answer for a first look.
- Standard — a balanced default: common ports with service/version detection.
- OS — adds operating-system fingerprinting.
- Full — all 65,535 ports with version detection (thorough, slower).
- Vuln — runs Nmap's vulnerability scripts against discovered services.
- Stealth — a quieter SYN scan that is less likely to be logged.
- UDP — scans UDP services (DNS, SNMP, etc.) that TCP scans miss.
What you get
A table of port · state · service · version, plus OS and script output where the mode provides it. Risky exposed services (RDP, SMB, databases) stand out, and the same data feeds Asset Inventory and the Security Score network factor — and, on the Fleet, the exposed-port detection rules.
Tips
- Start with Quick or Standard, then switch to Full/Vuln only on hosts that look interesting.
- UDP is slow by nature — scan a short port list unless you have time.
- No Nmap installed yet? A realistic demo result lets you try the workflow first; install Nmap from the Setup Wizard to scan for real.
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