Netflow/IPFIX/sFlow (UDP)

NetObserv Flow receives IPFIX, Netflow and sFlow network flow records and telemetry over UDP. By default the collector listens on all interfaces of the system where it is running. However it can be configured to listen on only a specific interface. The default UDP listening port is 9995, which can also be configured.

It is recommended that the collector be configured to request a larger than default receive buffer size. The size, in bytes, that the collector will request be created by the operating system kernel is configurable. If this value exceeds the maximum allowed buffer size (net.core.rmem_max on Linux), the maximum allowed size is used.

Received UDP PDUs are queued prior to being processed by an available decoder. This allows the collector to better handle temporary spikes of received packets without losing data. The default size of the queue is 512. This can be overridden using EF_FLOW_PACKET_STREAM_MAX_SIZE.

EF_FLOW_SERVER_UDP_IP

NetObserv Flow receives network flow records over UDP. This setting specifies the IP address of the interface on which the collector will listen.

• Valid Values

  • 0.0.0.0 or any valid IP address to which the UDP socket can be bound.

• Default

  • 0.0.0.0 (listen on all interfaces)

EF_FLOW_SERVER_UDP_PORT

The UDP port(s) on which the collector will create a socket to receive incoming packets. Multiple ports may be specified, separated by a comma. For example 2055,6343,4739

• Valid Values

  • Any valid port number. Common values include:

    • 2055: the standard port for Netflow

    • 4739: the standard port for IPFIX

    • 6343: the standard port for sFlow

    • 9995-9998: commonly use port numbers

• Default

  • 2055,4739,6343,9995

EF_FLOW_SERVER_UDP_READ_BUFFER_MAX_SIZE

The size, in bytes, of the UDP receive buffer that the UDP server will request be created by the operating system kernel when the socket is created. If this value exceeds the maximum allowed buffer size (net.core.rmem_max on Linux), the maximum allowed size is used.

• Default

  • 33554432

EF_FLOW_PACKET_STREAM_MAX_SIZE

Received UDP PDUs are queued prior to being processed by an available decoder. This value specifies the size of the queue as a quantity of PDUs.

• Default

  • 512