Overview

Use NetFlow Monitoring in Datadog to visualize and monitor your flow records from your NetFlow-enabled devices.

The NetFlow Monitoring page containing tabs for top sources, destinations, protocols, source ports, destination ports, and device trends

Installation

To use NetFlow Monitoring with Network Device Monitoring, ensure you are using the Agent version 7.45 or newer.

Note: Configuring metric collection from Network Device Monitoring is not a requirement for sending NetFlow data, although it is strongly recommended as this extra data can be used to enrich your flow records with information such as the device name, model, and vendor, as well as the inbound/outbound interface name.

Configuration

To configure your devices to send NetFlow, jFlow, sFlow, or IPFIX traffic to the Agent NetFlow server, your devices must be configured to send traffic to the IP address that the Datadog Agent is installed on, specifically the flow_type and port.

Edit your datadog.yaml Agent configuration file to enable NetFlow:

network_devices:
  netflow:
    enabled: true
    listeners:
      - flow_type: netflow9   # choices: netflow5, netflow9, ipfix, sflow5
        port: 2055            # devices must send traffic to this port
      - flow_type: netflow5
        port: 2056
      - flow_type: ipfix
        port: 4739
      - flow_type: sflow5
        port: 6343

After saving your changes, restart the Agent.

Aggregation

The Datadog Agent automatically aggregates the received NetFlow data in order to limit the number of records sent to the platform while maintaining most of the information. By default there is a five-minute aggregation interval, during which flow recordings which share the same identifying information (source and destination address and port, protocol, and so forth) are aggregated together. Additionally, the Datadog Agent can detect ephemeral ports and remove them. As a result, you may see Flows with port:*.

Enrichment

Your NetFlow data is processed by the Datadog backend and enriched with the available metadata from your devices and interfaces. Enrichment is based on the NetFlow exporter IP and the interface indexes. To disambiguate possible collisions between reused private IPs, you can configure a different namespace for each Agent configuration file (with the setting network_devices.namespace).

If the NetFlow exporter IP is one of the device IPs, but not the one configured on the SNMP integration, Datadog attempts to locate the device that the exporter IP belongs to, and enriches your NetFlow data with it is as long as the match is unique.

Cloud provider IP enrichment

Datadog enriches IPs with public cloud provider service and region for IPv4 addresses, so you can filter for flow records from a specific service and region.

Netflow IPs enriched with cloud provider name, region, and service

Port enrichment

Datadog enriches ports in NetFlow with IANA (Internet Assigned Numbers Authority) data to resolve well known port mappings (such as Postgres on 5432 and HTTPS on 443). This can be seen when searching for source or destination application names on NetFlow.

The NetFlow page filtered by @destination.application_name and displaying names for ports such as HTTPS

Custom port enrichment

You can also add your own custom enrichments to map ports and protocols to specific applications (for example, if a custom service runs on a specific port). This makes it easier for network engineers and their teams to interpret and query NetFlow data with human-readable names.

From the Configuration tab in NetFlow, click Add Enrichment to upload the CSV file containing your custom enrichments.

The New Enrichment Mapping modal in the Netflow configuration tab

Visualization

You can access the data collected by NetFlow Monitoring on the NetFlow page. Hover over a flow from the list for additional information about hosts, pods, and containers, and access related network connections.

Hover over a flow aggregated from a device emitting netflow to access related network connections

When creating a NetFlow monitor, you should consider the following fields with respect to the source IP or destination IP from the perspective of the device. These fields provide insights into network traffic patterns and help with optimizing performance and security.

Interface information

The following fields represent details about the ingress and egress interfaces.

Field NameField Description
Egress Interface AliasAlias of the egress interface.
Egress Interface IndexIndex of the egress interface.
Egress Interface NameName of the egress interface.
Ingress Interface AliasAlias of the ingress interface.
Ingress Interface IndexIndex of the ingress interface.
Ingress Interface NameName of the ingress interface.

Device information

The following fields represent details related to the device generating NetFlow records.

Field NameField Description
Device IPIP address used to map to a device in NDM for enrichment purposes.
Exporter IPIP address from which NetFlow packets originate.
Device ModelModel of the device.
Device NameName of the device.
Device NamespaceNamespace of the device.
Device VendorVendor of the device.

Flow details

The following fields represent characteristics of the network flow.

Field NameField Description
DirectionIndicates whether the flow is inbound or outbound.
Start TimeTimestamp of the first network packet between the source and destination IP addresses.
End TimeTimestamp of the last network packet between the source and destination IP addresses.
Ether TypeType of Ethernet frame encapsulation (IPv4 or IPv6).
Flow TypeType of NetFlow data format (IPFIX, sFlow5, NetFlow5, NetFlow9, or Unknown).
IP ProtocolProtocol used for communication (such as ICMP, TCP, or UDP).
Next Hop IPIP address of the next hop in the network path.
TCP FlagUnion of all TCP flags observed over the life of the flow.
BytesTotal number of bytes transferred.
PacketsTotal number of packets transferred.

In addition to fields, you can also use out-of-the-box facets to start analyzing traffic patterns based on NetFlow destination and source IP addresses.

NetFlow Destination IP facets

Facet NameFacet Description
Destination AS DomainThe domain associated with the Autonomous System (AS) to which the destination IP belongs.
Destination AS NameThe name of the Autonomous System (AS) to which the destination IP belongs.
Destination AS NumberThe number assigned to the Autonomous System (AS) to which the destination IP belongs.
Destination AS RouteThe route information associated with the Autonomous System (AS) to which the destination IP belongs.
Destination AS TypeThe type of Autonomous System (AS) to which the destination IP belongs (such as transit, customer, peer).
Destination Application NameThe name of the application associated with the destination IP.
Destination City NameThe name of the city associated with the destination IP.
Destination Cloud Provider NameThe name of the cloud provider associated with the destination IP.
Destination Cloud Provider RegionThe region of the cloud provider associated with the destination IP.
Destination Cloud Provider ServiceThe service provided by the cloud provider associated with the destination IP.
Destination Continent CodeThe code representing the continent associated with the destination IP.
Destination Continent NameThe name of the continent associated with the destination IP.
Destination Country ISO CodeThe ISO code representing the country associated with the destination IP.
Destination Country NameThe name of the country associated with the destination IP.
Destination IPThe destination IP address.
Destination LatitudeThe latitude coordinate associated with the destination IP.
Destination LongitudeThe longitude coordinate associated with the destination IP.
Destination MACThe Media Access Control (MAC) address associated with the destination IP.
Destination MaskThe subnet mask associated with the destination IP.
Destination PortThe destination port number.
Destination Subdivision ISO CodeThe ISO code representing the subdivision (such as state or province) associated with the destination IP.
Destination Subdivision NameThe name of the subdivision (such as state or province) associated with the destination IP.
Destination TimezoneThe timezone associated with the destination IP.

NetFlow Source IP facets

Facet NameFacet Description
Source AS DomainThe domain associated with the Autonomous System (AS) to which the source IP belongs.
Source AS NameThe name of the Autonomous System (AS) to which the source IP belongs.
Source AS NumberThe number assigned to the Autonomous System (AS) to which the source IP belongs.
Source AS RouteThe route information associated with the Autonomous System (AS) to which the source IP belongs.
Source AS TypeThe type of Autonomous System (AS) to which the source IP belongs (such as transit, customer, peer).
Source Application NameThe name of the application associated with the source IP.
Source City NameThe name of the city associated with the source IP.
Source Cloud Provider NameThe name of the cloud provider associated with the source IP.
Source Cloud Provider RegionThe region of the cloud provider associated with the source IP.
Source Cloud Provider ServiceThe service provided by the cloud provider associated with the source IP.
Source Continent CodeThe code representing the continent associated with the source IP.
Source Continent NameThe name of the continent associated with the source IP.
Source Country ISO CodeThe ISO code representing the country associated with the source IP.
Source Country NameThe name of the country associated with the source IP.
Source IPThe source IP address.
Source LatitudeThe latitude coordinate associated with the source IP.
Source LongitudeThe longitude coordinate associated with the source IP.
Source MACThe Media Access Control (MAC) address associated with the source IP.
Source MaskThe subnet mask associated with the source IP.
Source PortThe source port number.
Source Subdivision ISO CodeThe ISO code representing the subdivision (such as state or province) associated with the source IP.
Source Subdivision NameThe name of the subdivision (such as state or province) associated with the source IP.
Source TimezoneThe timezone associated with the source IP.

By monitoring these key fields and using facets to analyze NetFlow events, organizations can gain visibility into their network infrastructure, optimize performance, and improve security posture.

Create a dashboard with NetFlow data

This data is also available in dashboards and notebooks, enabling precise queries and correlation with other data sources. When creating a dashboard with NetFlow data, select NetFlow as the source in the Graph your data section.

Create a dashboard with NetFlow data

Retention

NetFlow data is retained for 30 days by default, with options for 15, 30, 60, and 90 day retention.

To retain NetFlow data for longer periods of time, contact your account representative.

Further Reading