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Flexible NetFlow Configuration Guide, Cisco IOS XE Fuji 16.8.x

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Book Title

Flexible NetFlow Configuration Guide, Cisco IOS XE Fuji 16.8.x

Chapter Title

Flexible NetFlow—IPv4 Unicast Flows

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Updated:
March 29, 2018

Chapter: Flexible NetFlow—IPv4 Unicast Flows

Flexible NetFlow—IPv4 Unicast Flows

The Flexible Netflow—IPv4 Unicast Flows feature enables Flexible NetFlow to monitor IPv4 traffic.

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.

Information About Flexible NetFlow IPv4 Unicast Flows

Flexible NetFlow—IPv4 Unicast Flows Overview

This feature enables Flexible NetFlow to monitor IPv4 traffic.

How to Configure Flexible NetFlow IPv4 Unicast Flows

Creating a Flow Record

Perform this task to configure a customized flow record.

Customized flow records are used to analyze traffic data for a specific purpose. A customized flow record must have at least one match criterion for use as the key field and typically has at least one collect criterion for use as a nonkey field.

There are hundreds of possible permutations of customized flow records. This task shows the steps that are used to create one of the possible permutations. Modify the steps in this task as appropriate to create a customized flow record for your requirements.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    flow record record-name

    4.    description description

    5.    match {ip | ipv6} {destination | source} address

    6.    Repeat Step 5 as required to configure additional key fields for the record.

    7.   

    8.    Repeat the above step as required to configure additional nonkey fields for the record.

    9.    end

    10.    show flow record record-name

    11.    show running-config flow record record-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 record record-name


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

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

    • This command also allows you to modify an existing flow record.

     
    Step 4 description description


    Example: 
    Device(config-flow-record)# description Used for basic traffic analysis
     

    (Optional) Creates a description for the flow record.

     
    Step 5 match {ip | ipv6} {destination | source} address


    Example: 
    Device(config-flow-record)# match ipv4 destination address
     
    Note   

    This example configures the IPv4 destination address as a key field for the record. For information about the other key fields available for the match ipv4 command, and the other match commands that are available to configure key fields.

     
    Step 6 Repeat Step 5 as required to configure additional key fields for the record.  

    —

     
    Step 7

    Example:
     

    Configures the input interface as a nonkey field for the record.

    Note   

    This example configures the input interface as a nonkey field for the record.

     
    Step 8 Repeat the above step as required to configure additional nonkey fields for the record.  

    —

     
    Step 9 end


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

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

     
    Step 10 show flow record record-name


    Example: 
    Device# show flow record FLOW_RECORD-1
     

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

     
    Step 11 show running-config flow record record-name


    Example: 
    Device# show running-config flow record FLOW_RECORD-1
     

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

     

    Configuring the Flow Exporter

    Perform this required task to configure the flow exporter.


    Note

    Each flow exporter supports only one destination.

    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 {ip-address | hostname} [vrf vrf-name]

      6.    dscp dscp

      7.    source interface-type interface-number

      8.    output-features

      9.    template data timeout seconds

      10.    transport udp udp-port

      11.    ttl seconds

      12.    end

      13.    show flow exporter exporter-name

      14.    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 the 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 the datacenter
       

      (Optional) Configures a description to the exporter that will appear in the configuration and the display of the show flow exporter command.

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


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

      Specifies the IP address or hostname of the destination system for the exporter.

      Note   

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

       
      Step 6 dscp dscp


      Example: 
      Device(config-flow-exporter)# dscp 63
       

      (Optional) Configures differentiated services code point (DSCP) parameters for datagrams sent by the exporter.

      • The range for the dscp argument is from 0 to 63. Default: 0.

       
      Step 7 source interface-type interface-number


      Example: 
      Device(config-flow-exporter)# source ethernet 0/0
       

      (Optional) Specifies the local interface from which the exporter will use the IP address as the source IP address for exported datagrams.

       
      Step 8 output-features


      Example: 
      Device(config-flow-exporter)# output-features
       

      (Optional) Enables sending export packets using quality of service (QoS) and encryption.

       
      Step 9 template data timeout seconds


      Example: 
      Device(config-flow-exporter)# template data timeout 120
       

      (Optional) Configures resending of templates based on a timeout.

      • The range for the seconds argument is 1 to 86400 (86400 seconds = 24 hours).

       
      Step 10 transport udp udp-port


      Example: 
      Device(config-flow-exporter)# transport udp 650
       

      Specifies the UDP port on which the destination system is listening for exported datagrams.

      • The range for the udp-port argument is from 1 to 65536.

       
      Step 11 ttl seconds


      Example: 
      Device(config-flow-exporter)# ttl 15
       

      (Optional) Configures the time-to-live (TTL) value for datagrams sent by the exporter.

      • The range for the seconds argument is from 1 to 255.

       
      Step 12 end


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

      Exits flow exporter configuration mode and returns to privileged EXEC mode.

       
      Step 13 show flow exporter exporter-name


      Example: 
      Device# show flow exporter FLOW_EXPORTER-1
       

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

       
      Step 14 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.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    flow monitor monitor-name

        4.    description description

        5.    record {record-name}

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


        Example:  
           
        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.

           

          Configuring and Enabling Flexible NetFlow with Data Export

          You must create a flow monitor to configure the types of traffic for which you want to export the cache data. You must enable the flow monitor by applying it to at least one interface to start exporting data. To configure and enable Flexible NetFlow with data export, perform this required task.

          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. The record format can be one of the predefined record formats, or an advanced user may create his or her own record format using the collect and matchcommands in Flexible NetFlow flow record configuration mode.


          Note

          You must remove a flow monitor from all of the interfaces to which you have applied it before you can modify the record format of the flow monitor.

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    flow monitor monitor-name

            4.    record {record-name | netflow-original | netflow {ipv4 | ipv6 record [peer] }]

            5.    exporter exporter-name

            6.    exit

            7.    interface type number

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

            9.    end

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


          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 monitor monitor-name


            Example:
            Device(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 record {record-name | netflow-original | netflow {ipv4 | ipv6 record [peer] }]


            Example:
            Device(config-flow-monitor)# record netflow ipv4 original-input
             

            Specifies the record for the flow monitor.

             
            Step 5 exporter exporter-name


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

            Specifies the name of an exporter that you created previously.

             
            Step 6 exit


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

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

             
            Step 7 interface type number


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

            Specifies an interface and enters interface configuration mode.

             
            Step 8 {ip | ipv6} flow monitor monitor-name {input | output}

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

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

             
            Step 9 end


            Example:
            Device(config-if)# end
             

            Exits interface configuration mode and returns to privileged EXEC mode.

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


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

            (Optional) Displays the status and statistics for a Flexible NetFlow flow monitor. This will verify data export is enabled for the flow monitor cache.

             

            Configuration Examples for Flexible NetFlow IPv4 Unicast Flows

            Example: Configuring Multiple Export Destinations

            The following example shows how to configure multiple export destinations for Flexible NetFlow for IPv4 or IPv6 traffic.

            This sample starts in global configuration mode: 

            !
flow exporter EXPORTER-1
 destination 172.16.10.2
 transport udp 90
 exit
!
flow exporter EXPORTER-2
 destination 172.16.10.3
 transport udp 90
 exit
!
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
 exporter EXPORTER-2
 exporter EXPORTER-1
!
!
flow monitor FLOW-MONITOR-2
 record v6_r1
 exporter EXPORTER-2
 exporter EXPORTER-1
!
ip cef
!
interface GigabitEthernet1/0/0
 ip address 172.16.6.2 255.255.255.0
 ipv6 address 2001:DB8:2:ABCD::2/48
 ip flow monitor FLOW-MONITOR-1 input
 ipv6 flow monitor FLOW-MONITOR-2 input
!

            The following display output shows that the flow monitor is exporting data to the two exporters: 

            Device# show flow monitor FLOW-MONITOR-1
Flow Monitor FLOW-MONITOR-1:
  Description:       User defined
  Flow Record:       v4_r1
  Flow Exporter:     EXPORTER-1
                     EXPORTER-2
  Cache:
    Type:              normal (Platform cache)
    Status:            allocated
    Size:              4096 entries / 311316 bytes
    Inactive Timeout:  15 secs
    Active Timeout:    1800 secs
    Update Timeout:    1800 secs

            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
!

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