Understanding NDE
Understanding NDE
These sections describe how NetFlow Data Export (NDE) works:
•
•
NDE Overview
NetFlow collects traffic statistics by monitoring packets that flow through the router and storing the
statistics in the NetFlow table. For more information about NetFlow, see
NetFlow".
NetFlow Data Export (NDE) converts the NetFlow table statistics into records and exports the records
to an external device, which is called a NetFlow collector.
In PFC3A mode, NDE exports statistics only for routed traffic. With a PFC3B or PFC3BXL, you can
configure NDE to export statistics for both routed and bridged traffic. Netflow for bridged traffic
requires Release 12.2(18)SXE or later.
You can export IP unicast statistics using NDE record format versions 5, 7 or 9. Use NDE version 8
record format for NetFlow aggregation, and version 9 record format for IP multicast. NetFlow version 9
export format is supported in Release 12.2(18)SXF and later.
Exporting a large volume of statistics can significantly impact SP and RP CPU utilization. You can
control the volume of records exported by configuring NDE flow filters to include or exclude flows from
the NDE export. When you configure a filter, NDE exports only the flows that match the filter criteria.
You can configure up to two external data collector addresses. A second data collector improves the
probability of receiving complete NetFlow data by providing redundant data streams. This feature is
available with the following releases and hardware:
•
•
NDE on the MSFC
NDE on the MSFC exports statistics for flows routed in software. The MSFC supports NetFlow
aggregation, described in this document:
Cisco IOS NetFlow Configuration Guide.
The MSFC also supports NetFlow ToS-based router aggregation, described in this document:
Cisco IOS NetFlow Configuration Guide.
Release 12.2(18)SXF and later releases support NetFlow sampling on the MSFC, described in this
document:
Cisco IOS NetFlow Configuration Guide.
Release 12.2(18)SXF and later releases support NetFlow version 9, described in this document:
Cisco IOS NetFlow Configuration Guide.
NetFlow version 9 record formats are described in this document:
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
51-2
NDE Overview, page 51-2
NDE on the MSFC, page 51-2
A PFC2 and Release 12.2(18)SXD and later releases
A PFC3 and Release 12.2(18)SXE and later releases
Chapter 51
Configuring NDE
Chapter 50, "Configuring
OL-4266-08