NetFlow module

This is a module for receiving NetFlow and IPFIX flow records over UDP. This input supports NetFlow versions 1, 5, 6, 7, 8 and 9, as well as IPFIX. For NetFlow versions older than 9, fields are mapped automatically to NetFlow v9.

This module wraps the netflow input to enrich the flow records with geolocation information about the IP endpoints by using an Elasticsearch ingest pipeline.

You can further refine the behavior of the netflow module by specifying variable settings in the modules.d/netflow.yml file, or overriding settings at the command line.

You must enable at least one fileset in the module. Filesets are disabled by default.

Each fileset has separate variable settings for configuring the behavior of the module. If you don’t specify variable settings, the netflow module uses the defaults.

For advanced use cases, you can also override input settings. See Override input settings.

The fileset is by default configured to listen for UDP traffic on localhost:2055. For most uses cases you will want to set the netflow_host variable to allow the input bind to all interfaces so that it can receive traffic from network devices.

- module: netflow
  log:
    enabled: true
    var:
      netflow_host: 0.0.0.0
      netflow_port: 2055

var.netflow_host

Address to bind to. Defaults to localhost.

var.netflow_port

Port to listen on. Defaults to 2055.

var.max_message_size

The maximum size of the message received over UDP. The default is 10KiB.

var.read_buffer

The size of the read buffer on the UDP socket.

var.timeout

The read and write timeout for socket operations.

var.expiration_timeout

The time before an idle session or unused template is expired. Only applicable to v9 and IPFIX protocols. A value of zero disables expiration.

var.queue_size

The maximum number of packets that can be queued for processing. Use this setting to avoid packet-loss when dealing with occasional bursts of traffic.

var.custom_definitions

A list of paths to field definitions YAML files. These allow to update the NetFlow/IPFIX fields with vendor extensions and to override existing fields. See netflow input for details.

var.detect_sequence_reset

Flag controlling whether Filebeat should monitor sequence numbers in the Netflow packets to detect an Exporting Process reset. See netflow input for details.

var.internal_networks

A list of CIDR ranges describing the IP addresses that you consider internal. This is used in determining the values of source.locality, destination.locality, and flow.locality. The values can be either a CIDR value or one of the named ranges supported by the network condition. The default value is [private] which classifies RFC 1918 (IPv4) and RFC 4193 (IPv6) addresses as internal.

var.tags

A list of tags to include in events. Including forwarded indicates that the events did not originate on this host and causes host.name to not be added to events. Defaults to [forwarded].

For a description of each field in the module, see the exported fields section.