Extreme Networks S- and K-Series Implementation

The Extreme Networks S- and K-Series flow-based architecture provides a powerful mechanism for collecting network flow statistics, with reporting capacity that scales with the addition of each S- or K-Series module. For each flow, packet and byte count statistics are collected by the S- or K-Series forwarding hardware. The flow report generation logic is distributed, permitting each module to report flows on its own ports.

The Extreme Networks S- and K-Series implementation enables the collection of NetFlow data on both switched and routed frames, allowing S- and K-Series modules 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.

NetFlow can be enabled on all ports on an S- and K-Series device, including fixed front panel ports, LAG ports and NEM 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 switched, the S- and K-Series firmware report the source and destination IfIndexes as physical ports. For flows that are routed, the S- and K-Series firmware report the source and destination ifIndexes as routed interfaces.

In the case of a LAG port, the module(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 module. The Engine ID field of the NetFlow Header is used to identify each unique module.