Appendix 1: device configuration, Enabling netflow export on an ios device, Appendix 1 – Fluke Computer Accessories User Manual

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User’s Guide – version 3.5

NetFlow Tracker

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Appendix 1: Device Configuration

This is a brief guide to setting up NetFlow on various types of device. Note that if your
device isn’t listed here it does not mean it is not supported by NetFlow Tracker; please

ask your device vendor for a guide to enabling NetFlow.

Enabling NetFlow Export/NDE on a Cisco Router or Layer 3

Switch

For more information on this subject, visit

http://www.cisco.com/go/netflow

. We

recommend that only people with experience in configuring Cisco devices follow these
steps. If in doubt, contact your network administrator or Cisco consultant. Note that if

you are running hybrid mode on a layer 3 switch you must configure IOS on the MSFC
and

CatOS

on the Supervisor Engine. Native IOS also requires

extra commands

; these

are documented below.

Enabling Netflow Export on an IOS Device

In configure mode on the router or MSFC, issue the following to enable NetFlow Export:

ip cef

This enables Cisco Express Forwarding, which is required for NetFlow in most
recent IOS releases.

ip flow-export destination <address> 2055

Use the address of your NetFlow Tracker machine and one of the ports

configured in the

Listener Ports

settings page. Port 2055 is monitored by

default.

ip flow-export source loopback 0

The source interface is used to set the source IP address of the NetFlow
exports sent by the router. NetFlow Tracker will make SNMP requests of the

router on this address. If you experience problems you can set the source
interface to an Ethernet or WAN interface instead of the loopback.

ip flow-export version 5 [peer-as | origin-as]

or

ip flow-export version 9 [peer-as | origin-as]

This sets the export version. Version 5 and Version 9 both support all of the

features NetFlow Tracker is capable of using; if you have a Native IOS switch
you may need to use version 9 to work around a bug – this is described below.

If your router uses BGP, you can specify that either the origin or peer ASes are
included in exports – it is not possible to include both.
Note that enabling or disabling NetFlow version 5 or version 9 (not version 1)
on a 12000 series router causes packet forwarding to stop for a few seconds

while the route processor and line card CEF tables are reloaded. To avoid

interruption of service to a live network, apply this command during a change
window, or include it in the startup-config file to be executed during a router

reboot.

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