ZMap is an open-source network scanner that enables researchers to easily perform Internet-wide network studies. With a single machine and a well provisioned network uplink, ZMap is capable of performing a complete scan of the IPv4 address space in under 45 minutes, approaching the theoretical limit of gigabit Ethernet.

ZMap can be used to study protocol adoption over time, monitor service availability, and help us better understand large systems distributed across the Internet.

ZMap is designed to perform comprehensive scans of the IPv4 address space or large portions of it. While ZMap is a powerful tool for researchers, please keep in mind that by running ZMap, you are potentially scanning the ENTIRE IPv4 address space at over 1.4 million packets per second. Before performing even small scans, we encourage users to contact their local network administrators and consult our list of scanning best practices.

By default, ZMap will perform a TCP SYN scan on the specified port at the maximum rate possible. A more conservative configuration that will scan 10,000 random addresses on port 80 at a maximum 10 Mbps can be run as follows:

$ zmap --bandwidth=10M --target-port=80 --max-targets=10000 --output-file=results.txt