Netflow receiver

Status
Stability	alpha: logs
Distributions	contrib
Issues
Code Owners	@evan-bradley, @dlopes7

The netflow receiver can listen for netflow, sflow, and ipfix data and convert it to OpenTelemetry logs. The receiver is based on the goflow2 project.

This gives OpenTelemetry users the capability of monitoring network traffic, and answer questions like:

• Which protocols are passing through the network?
• Which servers and clients are producing the highest amount of traffic?
• What ports are involved in these network calls?
• How many bytes and packets are being sent and received?

Getting started

By default the receiver will listen for ipfix and netflow on port 2055. The receiver can be configured to listen on different ports and protocols.

Example configuration:

receivers:
  netflow:
    - scheme: netflow
      port: 2055
      sockets: 16
      workers: 32
  netflow/sflow:
    - scheme: sflow
      port: 6343
      sockets: 16
      workers: 32

processors:
  batch:
    send_batch_size: 2000
    timeout: 30s

exporters:
  debug:
    verbosity: detailed

service:
  pipelines:
    logs:
      receivers: [netflow, netflow/sflow]
      processors: [batch]
      exporters: [debug]
  telemetry:
    logs:
      level: debug

We recommend using the batch processor to reduce the number of log requests being sent to the exporter. The batch processor will batch log records together and send them in a single request to the exporter.

You would then configure your network devices to send netflow, sflow, or ipfix data to the Collector on the specified ports.

Configuration

Field	Description	Examples	Default
scheme	The type of flow data that to receive	sflow, netflow	netflow
hostname	The hostname or IP address to bind to	localhost	0.0.0.0
port	The port to bind to	2055 or 6343	2055
sockets	The number of sockets to use	1	1
workers	The number of workers used to decode incoming flow messages	2	2
queue_size	The size of the incoming netflow packets queue, it will always be at least 1000.	5000	1000

Data format

The netflow data is standardized for the different schemas and is converted to OpenTelemetry log records following the semantic conventions

The log record will have the following attributes (with examples):

• source.address: Str(132.189.238.100)
• source.port: Int(1255)
• destination.address: Str(241.171.33.110)
• destination.port: Int(64744)
• network.transport: Str(tcp)
• network.type: Str(ipv4)
• flow.io.bytes: Int(853)
• flow.io.packets: Int(83)
• flow.type: Str(netflow_v5)
• flow.sequence_num: Int(191)
• flow.time_received: Int(1736309689918929427)
• flow.start: Int(1736309689830846400)
• flow.end: Int(1736309689871846400)
• flow.sampling_rate: Int(0)
• flow.sampler_address: Str(172.28.176.1)

The log record timestamps will be:

• Observed timestamp: The time the flow was received.
• Timestamp: The flow start field.

Schema support

netflow

• Process Template Records if present
• Process Netflow V5, V9, and IPFIX messages
• Extract the attributes documented above
• Mapping of custom fields is not yet supported

sflow

• Process sFlow version 5 datagrams
• flow_sample and flow_sample_expanded are supported.
• counter_sample and counter_sample_expanded are NOT yet supported.
• Mapping of custom fields is not yet supported