ZMap
ZMap is a single-packet network scanner designed for internet-wide research, such as measuring how many hosts answer on one port.
Legal & ethical use. Internet-wide scanning can generate abuse complaints; follow ZMap's published ethical-scanning guidance and only scan ranges you are authorised to scan. Use this tool only on systems, networks and data that you own or have explicit written permission to test. Unauthorised access or scanning can break computer-misuse laws (for example Pakistan's Prevention of Electronic Crimes Act, 2016, and equivalents elsewhere). Practise in your own lab or in authorised environments such as CTFs.
What it is used for
- Measure the deployment of a protocol or patch level across a range you may legally scan
- Academic measurement research
Key features
- Stateless, very high-speed probing
- Probe modules (TCP SYN, ICMP, UDP)
- Output modules and blocklists
Installation
Use your distribution package where available or build from the repository following the wiki.
Beginner usage guide
ZMap is for research-scale scanning, so read its documentation about ethical scanning (blocklists, rate limits, opt-out handling) before running anything beyond your own address space.
Example commands
Run these only against your own lab or authorised targets. Placeholder addresses such as 192.0.2.x are documentation ranges.
Check which hosts in a lab range answer on TCP 443
zmap -p 443 192.168.56.0/24 -o results.txtSends one SYN probe per address and writes responding IPs to results.txt.
References
Source verification
Last reviewed: 2026-10-27
Links checked over HTTP: 2026-10-27 07:51 UTC — official: 200, docs: 200, repo: 200
Commands were written from the official documentation and have not been executed on this site; test them in your lab.