Configuring Flexible NetFlow in Cisco 4500 with Supervisor Engine 7-E & Cisco IOS XE

 

Catalyst 4500 series switches with Supervisor Engine 7-E and Cisco IOS XE Software Release 3.1.0 SG supports Flexible NetFlow. The configuration of Flexible NetFlow in these switches is similar to the other regular Flexible NetFlow

Note: Flexible NetFlow is only supported on Supervisor Engine 7-E, Supervisor Engine 7L-E, and Catalyst 4500X.

 

Configuring Exporter

Enter global configuration mode on the router or MSFC, and issue the following commands for creating the exporter:

flow exporter {exporter_name}

destination {destination_ip_address}

Export-protocol version-9

transport udp 9996 

template data timeout 60

option application-table timeout 60

exit

Tip
Flow exporter can be configured with a unique name. Multiple Flow exporter profiles can be configured. Below is the configuration to configure Flow Exporter.

 

Configuring Flow Record 

ip flow record {record_name}

match datalink destination-vlan-id

match ipv4 version

match ipv4 tos

match ipv4 protocol

match ipv4 source address

match ipv4 destination address

match transport source-port

match transport destination-port

match interface input

match application names

collect interface output

collect counter bytes

collect counter packets

collect timestamp sys-uptime first

collect timestamp sys-uptime last

exit

Tip
Flow record configuration defines the fields exported via NetFlow protocol. Flexible pre-defined flow records are based on the original NetFlow ingress or egress caches. Cisco provides a unique keyword to identify the pre-defined records and these records can associated with a Flexible NetFlow Flow record configuration. 

 

Configuring Flow Monitor

ip flow monitor {monitor_name}

record {record_name}

exporter {exporter_name}

cache timeout active 60

cache timeout inactive 15

exit

 

Associate Flow Monitor to interface

Enter global configuration mode on the router or MSFC, and issue the following commands for each interface on which you want to enable NetFlow:

interface {interface} {interface_number}

ip flow monitor {onitor_name} input

Tip
Flow Monitor has to be attached to a specific physical or logical interface to export flow statistics for that particular interface. Above is the configuration to attach flow monitor to a specific interface.

 

Tip
Please note that NetFlow data export has to be enabled on all interfaces of a router in order to see accurate IN and OUT traffic. Suppose you have a router with interface A and B. Since NetFlow, by default, is done on an ingress basis, when you enable NetFlow data export on interface A, it will only export the IN traffic for interface A and OUT traffic for interface B. The OUT traffic for interface A will be contributed by the NetFlow data exported from interface B.

Even if you are interested in managing only interface A, please enable NetFlow data export on A and B. You may subsequently unmanage interface B from the License Management link.

 

Tip
For further information on configuring your IOS device for NetFlow data export, refer Cisco's NetFlow commands documentation
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