Configuring Netflow - Enterasys Matrix 2G4072-52 Configuration Manual

Logging And Network Management Command Set

Configuring NetFlow

11.2.8 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.
Matrix DFE Implementation
The 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 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 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.
When NetFlow is enabled, each DFE blade in the Matrix system will transmit a NetFlow packet
when:
•
It has accumulated the maximum number of NetFlow records per packet, which is 30, or
•
It has accumulated fewer than 30 NetFlow records and the active flow timer has expired, or
•
The flow expires (ages out or is invalidated).
11-152 Matrix DFE-Platinum and Diamond Series Configuration Guide