Cisco Systems 5, NAM manual Managing NetFlow Data Sources, Configuring NetFlow on Devices

Chapter 2 Setting Up The NAM Traffic Analyzer

Traffic

Figure 2-2 Sample NetFlow Network

Host A

Host B	Host C
	a
	b
	c
	Router

91629

Table 2-8, Reporting Flow Records lists the reported flows if NetFlow is enabled on interface a.

Table 2-8	Reporting Flow Records
Input Interface		Output Interface	Are Flows Reported?
a		b	Yes
a		c	Yes
b		c	No
b		a	No
c		a	No
c		b	No

Managing NetFlow Data Sources

A data source entry must exist on the NAM in order for it to accept NetFlow records from an external device. Data source entries may be created manually using the NAM web GUI or the CLI. When manually creating a data source, you may specify any name you want for the data source.

For convenience however, manual creation of NetFlow data sources is not necessary. There is an “auto-create” feature which is enabled by default. With the auto-create feature, a new data source will automatically be created for each device which sends NDE traffic to the NAM when the first packet is received.

Auto-created NetFlow data sources will be assigned a name in the format NDE-<IPAddress>-ID-<Integer>, where <IP Address> is the IP address of the exporting device, and <Integer> is the Engine-ID that the device populates in the packets (part of the NetFlow Data Export standard). An example might be “NDE-192.168.0.1-ID-12” for device 192.168.0.1 sending NDE packets with the Engine ID field set to 12. You can edit these auto-created data sources and change the name if you want to, as well as optionally specifying SNMP credentials for the device, as described later in this document.

Configuring NetFlow on Devices

The configuration commands for NetFlow devices to export NDE packets to the NAM are platform and device specific. The example configuration commands provided here are the ones most commonly found for devices running Cisco IOS. For more detailed information, see your device documentation.

	User Guide for the Cisco Network Analysis Module (NAM) Traffic Analyzer, 5.0
2-20	OL-22617-01