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Community Edition

FastNetMon - A high performance DoS/DDoS load analyzer built on top of multiple packet capture engines (NetFlow, IPFIX, sFlow, AF_PACKET, Netmap, PCAP).

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, switching off the server, or blackholing the client.

Flow is one or more ICMP, UDP, or TCP packets which can be identified via their unique src IP, dst IP, src port, dst port, and protocol fields.



Supported packet capture engines

  • NetFlow v5, v9, v9 Lite
  • sFlow v5
  • PCAP
  • AF_PACKET (recommended)
  • AF_XDP (developer branch only, XDP based capture)
  • Netmap (deprecated)
  • 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.

Official support groups:

Follow us at social media:

Complete integration with the following vendors


  • 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
  • Complete support for most popular attack types
  • Thresholds can be configured per-subnet basis with the hostgroups feature
  • Email notifications about detected attack
  • Complete IPv6 support
  • Announce blocked IPs via BGP to routers with ExaBGP or GoBGP (recommended)
  • Full integration with Graphite and InfluxDB
  • API
  • Redis integration
  • MongoDB integration
  • Supports L2TP decapsulation, VLAN untagging in mirror mode
  • Complete plug-in support
  • Capture attack fingerprints in PCAP format
  • Experimental BGP Flow Spec support, RFC 5575

Running FastNetMon

Hardware requirements

  • At least 1 GB of RAM


Router integration instructions


Main screen image

Example deployment scheme

Network diagramm