NetFlow v9

See Flow Support for details on flow support in Meridian.

Netflow v9 UDP Parser

The Netflow v9 UDP parser accepts packets received by a UDP listener and must forward them to a Netflow v9 adapter.

The Netflow v9 UDP parser supports protocol detection.

Facts

Class Name

org.opennms.netmgt.telemetry.protocols.netflow.parser.Netflow9UdpParser

Configuration and use

Table 1. Optional parameters for the Netflow v9 UDP parser
Parameter	Description	Default
templateTimeout	Templates must be redeclared in the given duration or they will be dropped.	30 minutes
maxClockSkew	The maximum delta in seconds between exporter and Minion timestamps.	0
clockSkewEventRate	Used to rate-limit clock skew events in seconds.	3600
dnsLookupsEnabled	Used to enable or disable DNS resolution for flows.	true
sequenceNumberPatience	A value > 1 enables checking for sequence number completeness. The value gives the size of the history buffer allowing flows to be processed out of order.	32
flowActiveTimeoutFallback	Fallback value for active flow timeout, if value is not included in exported flows.	none
flowInactiveTimeoutFallback	Fallback value for inactive flow timeout, if value is not included in exported flows.	none
flowSamplingIntervalFallback	Fallback value for sampling interval, if value is not included in exported flows.	none

The parameter maxClockSkew in your parser definition enables clock skew detection for exporters. It specifies the maximum delta in seconds between exporter and Minion timestamps. If exceeded, an alarm will be generated for the exporting device. The default value is 0, so clock skew detection is disabled. Furthermore, you can use the clockSkewEventRate parameter to rate-limit clock skew events. The default is 3600 seconds, so every hour an event will be sent.

Netflow v9 Adapter

The Netflow v9 adapter handles Netflow v9 payloads received and parsed by by the Netflow v9 UDP Parser. Flows are decoded from the messages into the canonical flow format and are published to the flow repository.

Facts

Class Name

org.opennms.netmgt.telemetry.protocols.netflow.adapter.netflow9.Netflow9Adapter

Configuration and use

Table 2. Required adapter-specific parameters
Parameter	Description	Default
applicationDataCollection	Enables data collection of bytesIn/bytesOut based on flow applications.	false
applicationThresholding	Enables thresholding based on flow applications.	false

For data collection to work properly you must also define a valid package definition inside your adapter configuration.