GitPedia

Fastnetmon

Very fast DDoS sensor with sFlow/Netflow/IPFIX/SPAN support

From pavel-odintsov·Updated June 20, 2026·View on GitHub·

Community Edition =========== FastNetMon - A high-performance DDoS detector/sensor built on top of multiple packet capture engines: NetFlow, IPFIX, sFlow, AF_PACKET (port mirror). The project is written primarily in C++, distributed under the GNU General Public License v2.0 license, first published in 2013. It has gained significant community traction with 3,672 stars and 586 forks on GitHub. Key topics include: analyzer, attack-detector, cisco, ddos, ddos-defender.

Latest release: v1.2.9 FastNetMon Community 1.2.9 Bellevue
May 31, 2026View Changelog →

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Community Edition

FastNetMon - A high-performance DDoS detector/sensor built on top of multiple packet capture engines: NetFlow, IPFIX, sFlow, AF_PACKET (port mirror).

What do we do?

We detect hosts in the deployed network sending or receiving large volumes of traffic, packets/bytes/flows per second and
perform a configurable action to handle that event. These configurable actions include notifying you, calling script or making BGP announcements.

Project

🌏️ Official site
⭐️ FastNetMon Advanced, Commercial Edition
🌟️ FastNetMon Advanced, free one-month trial
📜️ FastNetMon Advanced and Community difference table
📘️ Detailed reference

📖 FastNetMon Community Edition Terms and Conditions
🔏️ FastNetMon Community Edition Privacy Notice

FastNetMon is a product of FastNetMon LTD, UK. FastNetMon ® is a registered trademark in the UK and EU.

By installing or using this software, you confirm that you have read and agree to the FastNetMon Community Edition T&Cs and Privacy Notice, which will apply to your installation and use of the software

Installation

Supported packet capture engines

  • NetFlow v5, v9, v9 Lite
  • IPFIX
  • sFlow v5
  • PCAP
  • AF_PACKET (recommended)
  • AF_XDP (XDP based capture)
  • Netmap (deprecated, still supported only for FreeBSD)
  • PF_RING / PF_RING ZC (deprecated, available only for CentOS 6 in 1.2.0)

You can check out the comparison table for all available packet capture engines.

Features

  • Detects DoS/DDoS in as little as 1-2 seconds
  • Scales up to terabits on single server (sFlow, Netflow, IPFIX) or to 40G + in mirror mode
  • Trigger block/notify script if an IP exceeds defined thresholds for packets/bytes/flows per second
  • Thresholds can be configured per-subnet basis with the hostgroups feature
  • Email notifications about detected attack
  • Complete IPv6 support
  • Prometheus support: system metrics and total traffic counters
  • Flow and packet export to Kafka in JSON and Protobuf format
  • Announce blocked IPs via BGP to routers with ExaBGP or GoBGP (recommended)
  • Full integration with Clickhouse InfluxDB and Graphite
  • API
  • Redis integration
  • MongoDB protocol support compatible with native MongoDB and FerretDB
  • VLAN untagging in mirror and sFlow modes
  • Capture attack fingerprints in PCAP format

We track multiple platform and environment-specific metrics to understand ways how our product is being used and prioritise development accordingly.

Official support groups:

Follow us at social media:

Router integration instructions

Complete integration with the following vendors

Screenshots

Command line interface
Main screen image


Standard Grafana dashboard
Grafana total traffic

Example deployment scheme

Network diagramm

Upstream versions in different distributions

FastNetMon upstream distro packaging status

Contributors

Showing top 12 contributors by commit count.

View all contributors on GitHub →

This article is auto-generated from pavel-odintsov/fastnetmon via the GitHub API.Last fetched: 6/21/2026