Chapter 15: Netflow Configuration; Configuring Netflow; Enterasys Matrix Dfe Implementation; Operation - Enterasys Matrix DFE-Gold Series Configuration Manual

This chapter describes NetFlow commands and how to use them.

Configuring NetFlow

NetFlow is a protocol developed for collecting IP traffic information. Network devices (switches
and routers) with NetFlow enabled generate NetFlow flow records, which are exported from the
device in UDP packets and collected by a NetFlow collector.

Enterasys Matrix DFE Implementation

The Enterasys Matrix DFE flow‐based architecture provides a powerful mechanism for collecting
network flow statistics, with reporting capacity that scales with the addition of each DFE blade.
For each flow, packet and byte count statistics are collect by the DFE forwarding hardware. The
flow report generation logic is distributed, permitting each blade to report flows on its own ports.
The Enterasys Matrix DFE implementation enables the collection of NetFlow data on both
switched and routed frames, allowing DFE blades in all areas of a network infrastructure to collect
and report flow data. Routing does not need to be enabled to utilize NetFlow data collection. Flow
detail depends on the content of the frame and the path the frame takes through the switch.

Operation

NetFlow can be enabled on all ports on a Enterasys Matrix system, including fixed front panel
ports, LAG ports, NEM ports, and FTM1 backplane ports. Router interfaces which map to VLANs
may not be enabled directly.
NetFlow records are generated only for flows for which a hardware connection has been
established. As long as the network connection exists (and NetFlow is enabled), NetFlow records
will be generated. Flows that are switched in firmware (soft forwarded) will not have NetFlow
records reported. For flows that are routed, the DFE firmware reports the source and destination
ifIndexes as the physical ports, not routed interfaces.
In the case of a LAG port, the blade(s) that the physical ports are on will generate NetFlow records
independently. They will however, report the source ifIndex as the LAG port. The Flow Sequence
Counter field in the NetFlow Header is unique per blade. The Engine ID field of the NetFlow
Header is used to identify each unique blade. Each blade functions as a separate Netflow engine.
When NetFlow is enabled, each DFE blade in the Enterasys Matrix system will transmit a NetFlow
packet when:
Note: An Enterasys Feature Guide document that contains a complete discussion on NetFlow
configuration exists at the following Enterasys web site:
manuals/
NetFlow Configuration
http://www.enterasys.com/support/
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