Chapter 40 Configuring Netflow Statistics Collection; Overview Of Netflow Statistics Collection - Cisco 4500M Software Manual

Configuring NetFlow Statistics Collection
This chapter describes how to configure NetFlow Statistics on the Catalyst 4500 series switches. It also
provides guidelines, procedures, and configuration examples.
To use the NetFlow feature, you must have the Supervisor Engine V-10GE (the functionality is
Note
embedded in the supervisor engine), or the NetFlow Services Card (WS-F4531) and either a
Supervisor Engine IV or a Supervisor Engine V.
For complete syntax and usage information for the commands used in this chapter, refer to the
Note
Catalyst 4500 Series Switch Cisco IOS Command Reference and related publications at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/index.htm. Refer to the
NetFlow Solutions Guide for more detailed information on NetFlow usage and management.
The following topics are included:
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Overview of NetFlow Statistics Collection

A network flow is defined as a unidirectional stream of packets between a given source and destination
—both defined by a network-layer IP address and transport-layer port number. Specifically, a flow is
identified as the combination of the following fields: source IP address, destination IP address, source
port number, destination port number, protocol type, type of service, and input interface.
NetFlow Statistics is a global traffic monitoring feature that allows flow-level monitoring of all
IPv4-routed traffic through the switch using NetFlow Data Export (NDE). Collected statistics can be
exported to an external device (NetFlow Collector/Analyzer) for further processing. Network planners
can selectively enable NetFlow Statistics (and NDE) on a per-device basis to gain traffic performance,
control, or accounting benefits in specific network locations.
OL-6696-01
Overview of NetFlow Statistics Collection, page 40-1
NoteNetFlow support has hardware limitations that restrict the platform support to a subset of all
NetFlow fields. Specifically, TCP Flags and the ToS byte (DSCP) are not supported., page 40-6
Configuring NetFlow Statistics Collection, page 40-6
NetFlow Statistics Collection Configuration Example, page 40-11
NetFlow Configuration Examples, page 40-13
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