Configuring CPU Friendly NetFlow Export

The CPU Friendly NetFlow Export feature for Cisco IOS Flexible NetFlow provides the capability for the software NetFlow modules to adjust their Central Processing Unit (CPU) utilization based on user-configured CPU utlization thresholds for the supervisor and line cards. NetFlow will lower its CPU consumption when utilization exceeds the configured threshold, and vice versa.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for CPU Friendly NetFlow Export

  • The networking device must be running a Cisco release that supports Flexible NetFlow.

IPv4 Traffic

  • The networking device must be configured for IPv4 routing.

  • One of the following must be enabled on your router and on any interfaces on which you want to enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding.

IPv6 Traffic

  • The networking device must be configured for IPv6 routing.

  • One of the following must be enabled on your router and on any interfaces on which you want to enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding IPv6.

Information About CPU Friendly NetFlow Export

Overview of CPU Friendly NetFlow Export

The number and complexity of flow records to be exported is the prime cause of CPU use in NetFlow. The CPU Friendly NetFlow Export feature (also known as Yielding NetFlow Data Export, or Yielding NDE) monitors CPU use for both the supervisor and line cards according to user-configured thresholds and dynamically adjusts the rate of export as needed.

How to Configure CPU Friendly NetFlow Export

Configuring the CPU Utilization Threshold

To configure the CPU utilization threshold, the threshold above which NetFlow decreases its CPU consumption, perform the following required task.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. flow hardware [egress | export threshold total-cpu-threshold-percentage [ linecard linecard-threshold-percentage ] | usage notify {input | output } [table-threshold-percentage seconds ]]
  4. end
  5. show platform flow [aging | {export | usage | table-contention {aggregate | detailed | summary} } [instance | module] | {ip | ipv6} [ count | destination | instance | module | multicast | protocol | source ] | {layer2 | mpls } [ count | instance | module ]]

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

flow hardware [egress | export threshold total-cpu-threshold-percentage [ linecard linecard-threshold-percentage ] | usage notify {input | output } [table-threshold-percentage seconds ]]

Example:


Device(config)# flow hardware export threshold 25 linecard 25

Configures the CPU utilization threshold up to which NetFlow export is permitted.

Step 4

end

Example:


Device(config)# end

Ends the current configuration session and returns to privileged EXEC mode.

Step 5

show platform flow [aging | {export | usage | table-contention {aggregate | detailed | summary} } [instance | module] | {ip | ipv6} [ count | destination | instance | module | multicast | protocol | source ] | {layer2 | mpls } [ count | instance | module ]]

Example:


Device# show platform flow export

Verifies the configuration of the CPU utilization threshold.

Configuration Examples for CPU Friendly NetFlow Export

Example: Configuring CPU Utilization Thresholds for NetFlow Export

The following example shows how to configure CPU utilization thresholds for NetFlow export.

This sample starts in global configuration mode. 


!
flow hardware export threshold 25
flow hardware export threshold 25 linecard 25
end
!

Additional References

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

Flexible NetFlow conceptual information and configuration tasks

Flexible NetFlow Configuration Guide

Flexible NetFlow commands

Cisco IOS Flexible NetFlow Command Reference

Standards/RFCs

Standard

Title

No new or modified standards/RFCs are supported by this feature.

—

MIBs

MIB

MIBs Link

None

To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:

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

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for CPU Friendly NetFlow Export

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn . An account on Cisco.com is not required.


Note

The table below lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 1. Feature Information for CPU Friendly NetFlow Export

Feature Name

Releases

Feature Information

CPU Friendly NetFlow Export

12.2(50)SY

15.0(1)SY

15.0(1)SY1

The CPU Friendly NetFlow Export feature provides the capability for the software NetFlow modules to adjust their Central Processing Unit (CPU) utilization based on user configured CPU thresholds for the supervisor and line cards, so that when the total CPU utilization is above the configured threshold, NetFlow decreases its CPU consumption, and vice versa.

Information about the CPU Friendly NetFlow Export feature is included in the following sections:

The following commands were introduced or modified: flow hardware, show platform flow.