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Cisco CNS NetFlow Collection Engine User Guide, Release 5.0.2
OL-6899-01
Chapter 1 Overview
What Is CNS NetFlow Collection Engine?
Caution
Throughout this publication there are numerous examples of CNS NetFlow Collection Engine input
commands and output results. Included are examples of IP addresses. Be aware that IP address examples
are not usable IP addresses. The examples do not represent real-life configurations.
What Is CNS NetFlow Collection Engine?
CNS NetFlow Collection Engine provides fast, scalable, and economical data collection from multiple
export devices exporting NetFlow data records. Figure 1-1 shows an example of a typical NetFlow data
export scheme. In it, various export devices send export data to user-specified CNS NetFlow Collection
Engine UDP ports.
Figure 1-1
CNS NetFlow Collection Engine Overview
Each of the export devices in this example is configured for NetFlow data export. Part of the
configuration information for each export device includes the IP address and the UDP port number (a
logical port designator) that identify CNS NetFlow Collection Engine as the receiver of flows from this
export device. The UDP port number is a user-configurable designator: you can configure CNS NetFlow
Collection Engine to listen for flows on a number of different UDP ports, and then configure your export
devices so that each device exports flows to a dedicated UDP port, or have a number of devices export
flows to the same, shared UDP port.
After you configure and start CNS NetFlow Collection Engine, it listens to the user-specified UDP ports
for exported flows from the export devices you have configured for NetFlow data export.
CNS NetFlow Collection Engine performs the following functions:
•
NetFlow data collection from multiple export devices
•
Reduction in data volume through filtering and aggregation
•
Hierarchical data storage (helps client applications retrieve data)
•
File system space management
Exported NetFlow data
Router A
Router B
Switch 1
CNS NetFlow Collection
Engine workstation
Router C
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