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ZMap

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What ZMap is

ZMap is a free, open-source command-line scanner from the ZMap Project, a collection of measurement tools for large-scale studies of hosts and services on the public Internet. It uses single-packet probes for Internet-wide network surveys. On a typical gigabit Ethernet desktop, the project says it can scan the public IPv4 address space on one port in under 45 minutes; with a 10gigE connection plus netmap or PF_RING, the same scope can take under five minutes. Probe modules cover TCP SYN, ICMP, DNS queries, UPnP, and BACNET, and ZMap can send UDP probes. For stateful work, the related ZGrab scanner performs application-layer handshakes and collects service data, supporting HTTP, HTTPS, SSH, SMTP, Modbus, and BACNET. The project also lists ZDNS for DNS lookups, LZR for protocol identification, and ZLint for X.509 certificate checks. ZMap runs on GNU/Linux, macOS, and BSD. Installation guidance covers package managers and building from source, and a simple IPv4-space scan requires root privileges. Results can be exported as CSV, JSON, or plain text. The project warns that Internet-wide scanning can have serious ethical and operational implications, advising slow scans and an opt-out route for network operators.

Who it suits

ZMap is for researchers and operators conducting large-scale studies of hosts and services across the public Internet. It suits command-line users on GNU/Linux, macOS, or BSD who can install software and manage root privileges for IPv4-space scans.

What it does well

  • Free and open source under Apache License 2.0
  • Scans one IPv4 port in under 45 minutes on typical gigabit hardware
  • Supports TCP SYN, ICMP, DNS, UPnP, BACNET, and UDP probes
  • Works with ZGrab for stateful service measurements
  • Exports CSV, JSON, and plain-text results
  • Runs on GNU/Linux, macOS, and BSD

What to know first

  • A simple IPv4-space scan requires root privileges
  • ZMap itself does not provide service detection
  • Internet-wide scans carry ethical and operational implications

Limits

A simple scan of the IPv4 space requires root privileges. ZMap is a single-packet scanner without service detection; stateful application measurements use the related ZGrab tool.

Getting started

  1. Install ZMap through a supported package manager or build it from source
  2. Use a GNU/Linux, macOS, or BSD system
  3. Run the command-line scanner for the required Internet survey
  4. Use root privileges for a simple IPv4-space scan
  5. Export results as CSV, JSON, or plain text
  6. Consult the FAQ or GitHub Discussions for usage questions

Verdict

Choose ZMap for fast, broad network measurement from a command-line environment, especially when paired with the project’s related tools. Its free Apache-licensed code and multiple probe modules support large survey workflows. Look elsewhere if you need built-in service detection or cannot operate with root privileges for simple IPv4-space scans.

Questions

What does ZMap cost?

ZMap is free and open source, licensed under Apache License 2.0.

Which operating systems support ZMap?

It operates on GNU/Linux, macOS, and BSD.

What output formats are available?

ZMap can export CSV, JSON, and plain text.

Does ZMap detect services?

No. The project describes ZGrab as the related stateful scanner for handshakes and service data.

What privileges does scanning require?

The README says a simple scan of the IPv4 space requires root privileges.

How should Internet-wide scans be conducted?

The project advises scanning slowly and providing network operators a way to opt out because such scans can have ethical and operational implications.

Facts from ZMap's own pages

Ethical scanning
The project cautions that Internet-wide scans can have serious ethical and operational implications and advises scanning slowly and providing an opt-out for network operators. · github.com, 8 Oct 2026
High-speed scanning
With a 10gigE connection and netmap or PF_RING, ZMap can scan the IPv4 address space in under five minutes. · github.com, 8 Oct 2026
Installation
The project provides installation instructions for package managers and building from source. · github.com, 8 Oct 2026
Intended audience
The project describes its collection of open-source tools as intended for large-scale studies of hosts and services on the public Internet. · zmap.io, 8 Oct 2026
Intended users
The project describes ZMap as a tool for Internet-wide network surveys and lists research among the repository topics. · github.com, 8 Oct 2026
License
ZMap is licensed under Apache License 2.0. · github.com, 8 Oct 2026
Operating systems
ZMap operates on GNU/Linux, macOS, and BSD. · github.com, 8 Oct 2026
Platforms
The README says ZMap operates on GNU/Linux, Mac OS and BSD, and that the latest stable release supports Linux, macOS and BSD. · github.com, 8 Oct 2026
Privileges
The README's example scan requires root privileges. · github.com, 8 Oct 2026
Probe support
ZMap has probe modules for TCP SYN scans, ICMP, DNS queries, UPnP and BACNET, and can send UDP probes. · github.com, 8 Oct 2026
Probe types
ZMap has implemented probe modules for TCP SYN scans, ICMP, DNS queries, UPnP, and BACNET, and can send many UDP probes. · github.com, 8 Oct 2026
Project
The ZMap Project is a collection of open source measurement tools for large-scale studies of hosts and services on the public Internet. · zmap.io, 8 Oct 2026
Project tools
The project also lists ZDNS for DNS lookups, LZR for protocol identification, and ZLint for X.509 certificate checks. · zmap.io, 8 Oct 2026
Purpose
ZMap is a fast single-packet network scanner designed for Internet-wide network surveys. · github.com, 8 Oct 2026
Related scanner
ZGrab is the project's stateful application-layer scanner and supports protocols including HTTP, HTTPS, SSH, SMTP, Modbus and BACNET. · zmap.io, 8 Oct 2026
Related tool
The project describes ZGrab as a stateful application-layer scanner that can perform handshakes and collect service data from hosts found by ZMap. · zmap.io, 8 Oct 2026
Requirements
The README says a simple scan of the IPv4 space requires root privileges. · github.com, 8 Oct 2026
Scanning guidance
The README warns that Internet-wide scanning can have ethical and operational implications and advises scanning as slowly as necessary and providing network operators a way to opt out. · github.com, 8 Oct 2026
Scan speed
On a typical gigabit Ethernet desktop, ZMap can scan the public IPv4 address space on one port in under 45 minutes. · github.com, 8 Oct 2026
Support
The README directs users to the FAQ and GitHub Discussions for usage and support questions. · github.com, 8 Oct 2026
Workflow
The project describes using ZGrab with ZMap in measurement pipelines for more involved scans such as banner grabs or TLS handshakes. · github.com, 8 Oct 2026

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