Flexible NetFlow Egress support

The Flexible NetFlow Eggress support feature supports the monitoring of traffic that a router is transmitting on an interface or subinterface.

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Information About Flexible NetFlow Egress support

Flexible NetFlow - Egress support Overview

The Flexible NetFlow Egress support feature supports the monitoring of traffic that a device is transmitting on an interface or subinterface.

The feature is enabled by applying a flow monitor in output (egress) mode on the transmitting device.

If you configure a Flexible NetFlow exporter for the flow monitors you use for the Flexible NetFlow - Egress support feature, the transmitting device will export the captured flows to the configured collector devices in the provider network.

How to Configure Flexible NetFlow Egress support

Configuring a Flow Exporter for the Flow Monitor

Perform this optional task to configure a flow exporter for the flow monitor in order to export the data that is collected by Flexible NetFlow to a remote system for further analysis and storage.

Flow exporters are used to send the data that you collect with Flexible NetFlow to a remote system such as a NetFlow Collection Engine. Exporters use UDP as the transport protocol and use the Version 9 export format.


Note

Each flow exporter supports only one destination. If you want to export the data to multiple destinations, you must configure multiple flow exporters and assign them to the flow monitor.

You can export to a destination using either an IPv4 or IPv6 address.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    flow exporter exporter-name

    4.    description description

    5.    destination {hostname | ip-address} [vrf vrf-name]

    6.    export-protocol {netflow-v5 | netflow-v9 | ipfix}

    7.    transport udp udp-port

    8.    exit

    9.    flow monitor flow-monitor-name

    10.    exporter exporter-name

    11.    end

    12.    show flow exporter exporter-name

    13.    show running-config flow exporter exporter-name


DETAILED STEPS
     Command or ActionPurpose
    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 exporter exporter-name


    Example:
    Device(config)# flow exporter EXPORTER-1
     

    Creates a flow exporter and enters Flexible NetFlow flow exporter configuration mode.

    • This command also allows you to modify an existing flow exporter.
     
    Step 4 description description


    Example:
    Device(config-flow-exporter)# description Exports to datacenter
     

    (Optional) Creates a description for the flow exporter.

     
    Step 5 destination {hostname | ip-address} [vrf vrf-name]


    Example:
    Device(config-flow-exporter)# destination 172.16.10.2
     

    Specifies the hostname or IP address of the system to which the exporter sends data.

    Note   

    You can export to a destination using either an IPv4 or IPv6 address.

     
    Step 6 export-protocol {netflow-v5 | netflow-v9 | ipfix}


    Example:
    Device(config-flow-exporter)# export-protocol netflow-v9
     

    Specifies the version of the NetFlow export protocol used by the exporter.

    • Default: netflow-v9.
     
    Step 7 transport udp udp-port


    Example:
    Device(config-flow-exporter)# transport udp 65
     

    Configures UDP as the transport protocol and specifies the UDP port on which the destination system is listening for exported Flexible NetFlow traffic.

     
    Step 8 exit


    Example:
    Device(config-flow-exporter)# exit
     

    Exits Flexible NetFlow flow exporter configuration mode and returns to global configuration mode.

     
    Step 9 flow monitor flow-monitor-name


    Example:
    Device(config)# flow monitor FLOW-MONITOR-1
     

    Enters Flexible NetFlow flow monitor configuration mode for the flow monitor that you created previously.

     
    Step 10 exporter exporter-name


    Example:
    Device(config-flow-monitor)# exporter EXPORTER-1
     

    Specifies the name of an exporter that you created previously.

     
    Step 11 end


    Example:
    Device(config-flow-monitor)# end
     

    Exits Flexible NetFlow flow monitor configuration mode and returns to privileged EXEC mode.

     
    Step 12 show flow exporter exporter-name


    Example:
    Device# show flow exporter FLOW_EXPORTER-1
     

    (Optional) Displays the current status of the specified flow exporter.

     
    Step 13 show running-config flow exporter exporter-name


    Example:
    Device<# show running-config flow exporter FLOW_EXPORTER-1
     

    (Optional) Displays the configuration of the specified flow exporter.

     

    Creating a Flow Monitor

    Perform this required task to create a customized flow monitor.

    Each flow monitor has a separate cache assigned to it. Each flow monitor requires a record to define the contents and layout of its cache entries. These record formats can be a user-defined format. An advanced user can create a customized format using the flow record command.

    Before You Begin

    If you want to use a customized record, you must create the customized record before you can perform this task. If you want to add a flow exporter to the flow monitor for data export, you must create the exporter before you can complete this task.


    Note

    You must use the no ip flow monitor command to remove a flow monitor from all of the interfaces to which you have applied it before you can modify the parameters for the record command on the flow monitor. For information about the ip flow monitor command, refer to the Cisco IOS Flexible NetFlow Command Reference.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    flow monitor monitor-name

      4.    description description

      5.    record {record-name}

      6.    cache {timeout {active} seconds | type { normal }

      7.    Repeat Step 6 as required to finish modifying the cache parameters for this flow monitor.

      8.    exporter exporter-name

      9.    end

      10.    show flow monitor [[name] monitor-name [cache [format {csv | record | table}]] ]

      11.    show running-config flow monitor monitor-name


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example: 
      > enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.
       
      Step 2 configure terminal


      Example: 
      # configure terminal
       

      Enters global configuration mode.

       
      Step 3 flow monitor monitor-name


      Example: 
      (config)# flow monitor FLOW-MONITOR-1
       

      Creates a flow monitor and enters Flexible NetFlow flow monitor configuration mode.

      • This command also allows you to modify an existing flow monitor.
       
      Step 4 description description


      Example: 
      (config-flow-monitor)# description Used for basic ipv4 traffic analysis
       

      (Optional) Creates a description for the flow monitor.

       
      Step 5 record {record-name}


      Example: 
      (config-flow-monitor)# record FLOW-RECORD-1
       

      Specifies the record for the flow monitor.

       
      Step 6 cache {timeout {active} seconds | type { normal }


      Example: 
      Device(config-flow-monitor)# cache type normal
       
         
      Step 7 Repeat Step 6 as required to finish modifying the cache parameters for this flow monitor.  

      —

       
      Step 8 exporter exporter-name


      Example: 
      (config-flow-monitor)# exporter EXPORTER-1
       

      (Optional) Specifies the name of an exporter that was created previously.

       
      Step 9 end


      Example: 
      (config-flow-monitor)# end
       

      Exits Flexible NetFlow flow monitor configuration mode and returns to privileged EXEC mode.

       
      Step 10 show flow monitor [[name] monitor-name [cache [format {csv | record | table}]] ]


      Example: 
      # show flow monitor FLOW-MONITOR-2 cache
       

      (Optional) Displays the status for a Flexible NetFlow flow monitor.

       
      Step 11 show running-config flow monitor monitor-name


      Example: 
      # show running-config flow monitor FLOW_MONITOR-1
       

      (Optional) Displays the configuration of the specified flow monitor.

       

      Applying a Flow Monitor to an Interface

      Before it can be activated, a flow monitor must be applied to at least one interface. Perform this required task to activate a flow monitor.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    interface type number

        4.    {ip | ipv6} flow monitor monitor-name {input | output}

        5.    Repeat Steps 3 and 4 to activate a flow monitor on any other interfaces in the device over which you want to monitor traffic.

        6.    end

        7.    show flow interface type number

        8.    show flow monitor name monitor-name cache format record


      DETAILED STEPS
         Command or ActionPurpose
        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 interface type number


        Example:
        Device(config)# interface GigabitEthernet 0/0/0
         

        Specifies an interface and enters interface configuration mode.

         
        Step 4 {ip | ipv6} flow monitor monitor-name {input | output}

        Example:
        Device(config-if)# ip flow monitor FLOW-MONITOR-1 input
         

        Activates a flow monitor that was created previously by assigning it to the interface to analyze traffic.

         
        Step 5 Repeat Steps 3 and 4 to activate a flow monitor on any other interfaces in the device over which you want to monitor traffic.  

        —

         
        Step 6 end


        Example:
        Device(config-if)# end
         

        Exits interface configuration mode and returns to privileged EXEC mode.

         
        Step 7 show flow interface type number


        Example:
        Device# show flow interface GigabitEthernet 0/0/0
         

        Displays the status of Flexible NetFlow (enabled or disabled) on the specified interface.

         
        Step 8 show flow monitor name monitor-name cache format record


        Example:
        Device# show flow monitor name FLOW_MONITOR-1 cache format record
         

        Displays the status, statistics, and flow data in the cache for the specified flow monitor.

         

        Configuration Examples for Flexible NetFlow Egress support

        Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6 Traffic

        The following example shows how to configure Flexible NetFlow egress accounting for IPv4 and IPv6 traffic.

        This example starts in global configuration mode. 

        !
flow record v4_r1
match ipv4 tos
match ipv4 protocol
match ipv4 source address
match ipv4 destination address
match transport source-port
match transport destination-port
collect counter bytes long
collect counter packets long
!
flow record v6_r1
match ipv6 traffic-class
match ipv6 protocol
match ipv6 source address
match ipv6 destination address
match transport source-port
match transport destination-port
collect counter bytes long
collect counter packets long
!
flow monitor FLOW-MONITOR-1
 record v4_r1
 exit
!
!
flow monitor FLOW-MONITOR-2
 record v6_r1
 exit
!
ip cef
ipv6 cef
!
interface GigabitEthernet0/0/0
 ip address 172.16.6.2 255.255.255.0
 ipv6 address 2001:DB8:2:ABCD::2/48
 ip flow monitor FLOW-MONITOR-1 output
 ipv6 flow monitor FLOW-MONITOR-2 output
!

        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 Flexible NetFlow - Egress support

        The following table provides release information about the feature or features described in this module. This table 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.

        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.

        Table 1 Feature Information for Flexible NetFlow - Egress support

        Feature Name

        Releases

        Feature Information

        Flexible NetFlow - Egress support

        Cisco IOS XE Release 3.1S

        Cisco IOS XE Release 3.2SE

        This feature supports the monitoring of traffic that a router is transmitting on an interface or subinterface.

        No commands were introduced or modified by this feature.