Spoofer Logo Spoofer: A diagram explaining how the Spoofer tool helps to protect your network and the global Internet

Seeking to minimize Internet's susceptibility to spoofed DDoS attacks, we are developing and supporting open-source software tools to assess and report on the deployment of source address validation (SAV) best anti-spoofing practices. This project includes applied research, software development, new data analytics, systems integration, operations and maintenance, and an interactive analysis and reporting service.

We have developed and support a new client-server system for Windows, MacOS, and UNIX-like systems that periodically tests a network's ability to both send and receive packets with forged source IP addresses (spoofed packets). We are (in the process of) producing reports and visualizations that will inform operators, response teams, and policy analysts. The system measures different types of forged addresses, including private and neighboring addresses. The test results will allow us to analyze characteristics of networks deploying source address validation (e.g., network location, business type).

Please download our Spoofer Project Brochure to learn how you can help protect your network, your customers and the Internet.

Recent updates:


We generate a summary report on the current “state” of Internet IP source address spoofing/filtering using data from an active measurement tool. Thus far, we’ve collected data from thousands of clients, networks and providers. More details and published results from our research are also available.

Download Client Software

Please help! By downloading and running our client software, you’ll help advance the collective understanding of how to better protect the Internet. See screenshots of the tester in action, and a FAQ if you have questions. The following client packages are available. The sources should compile on any POSIX system. Please contact the mailing list with any issues or questions.

Client Software Build Description Notes
Spoofer-1.4.12-win32.exe Windows Binary Installer (signed)
Spoofer-1.4.12-macos.pkg macOS Binary Installer (signed)
Spoofer-1.4.12 PPA Ubuntu packages for: bionic focal jammy kinetic (signed) apt-add-repository ppa:spoofer-dev/spoofer
spoofer-1.4.12.tar.gz Source Code
changelog.txt ChangeLog

Why does IP spoofing matter?

Our FAQ covers common questions about spoofing relevance. The IP spoofing vulnerability is the most fundamental vulnerability of the TCP/IP architecture, which has proven remarkably scalable, in part due to the design choice to leave responsibility for security to the end hosts. Thus, the TCP/IP Internet architecture includes no explicit notion of authenticity. New spoofing-based attacks regularly appear (most recently against the DNS infrastructure) despite decades of previous exploits and prevention/tracing attempts. Current spoofing prevention mechanisms suffer from incentive issues (employing filtering does not prevent a provider from receiving spoofed source packets), deployment difficulty and management complexity. Our research seeks to inform architectural design, and security and policy mechanisms for preventing future attacks.

Watch the Video: “What is IP Spoofing?” on YouTube.


The spoofer program attempts to send a series of spoofed UDP packets to servers distributed throughout the world. These packets are designed to test:

  • Different classes of spoofed IPv4 and IPv6 addresses, including private and routable
  • Ability to spoof neighboring, adjacent addresses
  • Ability to spoof inbound (towards the client) and outbound (from the client)
  • Where along the path filtering is observed
  • Presence of a NAT device along the path

Request notifications of spoofing

If you would like to be notified when we detect spoofed packets from your autonomous system, please sign up on our registration page.

Spoofer in the News





Development Team


We welcome questions and feedback to the Spoofer Information Mailing List and invite users to join the Spoofer Users Mailing List for discussion and announcements.

Funding support

Department of Homeland Security (DHS) National Science Foundation (NSF)

The Spoofer project was sponsored by the Department of Homeland Security (DHS) Science and Technology Directorate, Homeland Security Advanced Research Projects Agency, Cyber Security Division (DHS S&T/HSARPA/CSD) BAA HSHQDC-14-R-B0005, the Government of United Kingdom of Great Britain and Northern Ireland via contract number D15PC00188. DHS funding of the Spoofer project ended in 2020, after which the project was sustained by National Science Foundation (NSF) OAC-1724853. The views and conclusions contained herein do not necessarily representing the official policies or endorsements, either expressed or implied, of DHS, NSF, the U.S. Government, or the Government of United Kingdom of Great Britain and Northern Ireland. Project originally invented and hosted by MIT ANA.

See https://catalog.caida.org/search?query=types=software%20links=tag:caida%20spoofer to explore related objects to this document in the CAIDA Resource Catalog.

Additional Content

Spoofer Data API

This page documents the Spoofer Data API.

Spoofer: Tracefilter

Conventional wisdom dictates that ingress filtering is performed near the edges of the network rather than the core. In addition to the nature and extent of IP spoofing, we also seek to understand where in the network filtering is employed with a new, novel technique we call tracefilter.

Sample Session Traces

Sample Spoofer session traces

Sample Spoofer Screenshots

What can you expect when you run the Spoofer tester? Here, we provide screen shots.

Sample Session Report

Sample Spoofer session report

Spoofer: FAQ

Frequently Asked Questions answered about the Spoofer project.

Spoofer: History

Historical updates regarding the status of Spoofer leading up to CAIDA’s stewardship of the project.

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