Flexible Netflow Configuration Guide, Cisco IOS Release 15M&T
Configuring IPv4 Multicast Statistics Support for Flexible NetFlow
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Configuring IPv4 Multicast Statistics Support for Flexible NetFlow

Configuring IPv4 Multicast Statistics Support for Flexible NetFlow

This document contains information about and instructions for configuring the Cisco IOS Flexible NetFlow - IPv4 Multicast Statistics Support feature. Prior to the introduction of the Flexible NetFlow - IPv4 Multicast Statistics Support feature, Flexible NetFlow could analyze IPv4 multicast traffic, but could not report the number of replicated bytes or the number of replicated packets in multicast flows. The Flexible NetFlow - IPv4 Multicast Statistics Support feature adds the capability of reporting the number of replicated bytes and the number of replicated packets in multicast flows to Flexible NetFlow.

NetFlow is a Cisco IOS technology that provides statistics on packets flowing through a networking device. NetFlow is the standard for acquiring IP operational data from IP networks. NetFlow provides provides data to support network and security monitoring, network planning, traffic analysis, and IP accounting.

Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex configurations for traffic analysis and data export through the use of reusable configuration components.

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 at the end of this module.

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 Configuring IPv4 Multicast Statistics Support

  • The networking device is running a Cisco IOS release that supports the Flexible NetFlow--IPv4 Multicast Statistics Support feature.
  • The networking device is configured for IPv4 unicast routing and IPv4 multicast routing.
  • One of the following is enabled on your networking device and on any interfaces on which you want to enable Flexible NetFlow: Cisco Express Forwarding, distributed Cisco Express Forwarding.

Restrictions for Configuring IPv4 Multicast Statistics Support

IPv4 Traffic

  • When the replication-factor field is used in a flow record, it will only have a nonzero value in the cache for ingress multicast traffic that is forwarded by the router. If the flow record is used with a flow monitor in output (egress) mode and to monitor unicast traffic, the cache data for the replication factor field is set to 0.

IPv6 Traffic

  • Traffic monitoring for multicast statistics is not supported.

Information About IPv4 Multicast Statistics Support

Replicated Bytes and Packets Reporting

The Flexible NetFlow--IPv4 Multicast Statistics Support feature adds the capability of reporting the number of replicated bytes and the number of replicated packets in multicast flows to Flexible NetFlow. You can capture the packet-replication factor for a specific flow and for each outgoing stream.

You can use the The Flexible NetFlow--IPv4 Multicast Statistics Support feature to identify and count multicast packets on the ingress side or the egress side (or both sides) of a networking device. Multicast ingress accounting provides information about the source and how many times the traffic was replicated. Multicast egress accounting monitors the destination of the traffic flow.

How to Configure IPv4 Multicast Statistics Support

Configuring IPv4 Multicast Statistics Support

This task explains the steps that are used to configure multicast statistics support for IPv4 traffic.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    flow record flow-record-name

    4.    description description

    5.    match routing is-multicast

    6.    Add key fields for the record as required using other match commands.

    7.    collect counter {bytes replicated [long] | packets replicated [long]}

    8.    collect routing multicast replication-factor

    9.    Add nonkey fields for the record as required using other collect commands.

    10.    exit

    11.    flow monitor monitor-name

    12.    description description

    13.    record record-name

    14.    exit

    15.    interface type number

    16.    ip flow monitor monitor-name [multicast | unicast] {input | output}

    17.    Repeat Steps 15 and 16 to activate a flow monitor on any other interfaces in the networking device over which you want to monitor traffic.

    18.    end

    19.    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 record flow-record-name


    Example:
    Device(config)# flow record FLOW-RECORD-2
     

    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 IPv4 multicast traffic analysis
     

    (Optional) Creates a description for the flow record.

     
    Step 5 match routing is-multicast


    Example:
    Device(config-flow-record)# match routing is-multicast
     

    Configures IPv4 multicast destination addresses (indicating that the IPv4 traffic is multicast traffic) as a key field for the flow record.

     
    Step 6 Add key fields for the record as required using other match commands.  

    For information about the other match commands that are available to configure key fields, refer to the Cisco IOS Flexible NetFlow Command Reference.

     
    Step 7 collect counter {bytes replicated [long] | packets replicated [long]}


    Example:
    Device(config-flow-record)# collect counter packets replicated
     

    Configures the number of bytes or packets multiplied by the multicast replication factor (number of interfaces the multicast traffic is forwarded over) as a nonkey field.

    • Default: Uses a 32-bit counter. The long keyword configures a 64-bit counter.
     
    Step 8 collect routing multicast replication-factor


    Example:
    Device(config-flow-record)# collect routing multicast replication-factor
     

    Configures the multicast replication factor (number of interfaces over which multicast traffic is forwarded) as a nonkey field.

     
    Step 9 Add nonkey fields for the record as required using other collect commands.  

    For information about the other collect commands that are available to configure nonkey fields, refer to the Cisco IOS Flexible NetFlow Command Reference.

     
    Step 10 exit


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

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

     
    Step 11 flow monitor monitor-name


    Example:
    Device(config)# flow monitor FLOW-MONITOR-2
     

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

    • This command also allows you to modify an existing flow monitor.
     
    Step 12 description description


    Example:
    Device(config-flow-monitor)# description Used for IPv4 multicast traffic analysis
     

    (Optional) Creates a description for the flow monitor.

     
    Step 13 record record-name


    Example:
    Device(config-flow-monitor)# record FLOW-RECORD-2 
     

    Specifies the record for the flow monitor.

     
    Step 14 exit


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

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

     
    Step 15 interface type number


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

    Specifies an interface and enters interface configuration mode.

     
    Step 16 ip flow monitor monitor-name [multicast | unicast] {input | output}


    Example:
    Device(config-if)# ip flow monitor FLOW-MONITOR-2 input
     

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

    • To monitor only multicast traffic, use the multicast keyword.
    • Default: Unicast traffic and multicast traffic are monitored.
     
    Step 17 Repeat Steps 15 and 16 to activate a flow monitor on any other interfaces in the networking device over which you want to monitor traffic.  

    --

     
    Step 18 end


    Example:
    Device(config-if)# end
     

    Exits interface configuration mode and returns to privileged EXEC mode.

     
    Step 19 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.

     

    Examples

    The following output from the show flow monitor command shows four multicast flows and three unicast flows:

    Device# show flow monitor FLOW-MONITOR-2 cache
     
    Cache type:                            Normal
      Cache size:                              4096
      Current entries:                            8
      High Watermark:                             8
      Flows added:                             4074
      Flows aged:                              4066
        - Active timeout   (  1800 secs)         46
        - Inactive timeout (    15 secs)       4020
        - Event aged                              0
        - Watermark aged                          0
        - Emergency aged                          0
    IP IS MULTICAST  IPV4 DST ADDR      pkts rep
    ===============  ===============  ==========
    Yes              224.192.16.1          16642
    Yes              224.192.65.1          16621
    No               10.1.4.2                  0
    No               10.1.2.2                  0
    No               10.1.3.2                  0
    Yes              224.0.0.13                0
    No               255.255.255.255           0
    Yes              224.0.0.1                 0

    Configuration Examples for IPv4 Multicast Statistics Support

    Example: Configuring IPv4 Multicast Statistics Support

    This example shows how to configure the following:

    • IPv4 multicast destination addresses (indicating that the IPv4 traffic is multicast traffic) as a key field.
    • The destination IPv4 address as a key field.
    • The replicated packet count as a nonkey field.
    • The replication factor as a nonkey field.
    • The flow monitor in order to monitor only multicast traffic.

    This sample starts in global configuration mode:

    !
    flow record FLOW-RECORD-2
     match routing is-multicast
     match ipv4 destination address
     collect counter packets replicated
     collect routing multicast replication-factor
     exit
    !
    flow monitor FLOW-MONITOR-2
     record FLOW-RECORD-2
     exit
    !
    interface GigabitEthernet 0/0/0
     no shut
     ip address 10.1.1.2 255.255.255.0
     ip flow monitor FLOW-MONITOR-2 multicast input
    !
    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 IPv4 Multicast Statistics 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 --IPv4 Multicast Statistics Support

    Feature Name

    Releases

    Feature Information

    Flexible NetFlow--IPv4 Multicast Statistics Support

    12.2(33)SRE

    12.2(50)SY

    12.4(22)T

    15.0(1)SY

    15.0(1)SY1

    The Flexible NetFlow--IPv4 Multicast Statistics Support feature adds the capability of reporting the number of replicated bytes and the number of replicated packets in multicast flows to Flexible NetFlow.

    Support for this feature was added for Cisco 7200 and 7300 Network Processing Engine (NPE) series routers in Cisco IOS Release 12.2(33)SRE.

    The following commands were introduced or modified: collect counter, collect routing is-multicast, collect routing multicast replication-factor, match routing is-multicast, match routing multicast replication-factor, ip flow monitor, ipv6 flow monitor.