Flexible Netflow Configuration Guide, Cisco IOS XE Release 3SE (Cisco WLC 5700 Series)
Flexible NetFlow Full Flow support
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Flexible NetFlow Full Flow support

Flexible NetFlow - Full Flow support

Last Updated: January 29, 2013

The Flexible NetFlow - Full Flow support feature enables Flexible NetFlow to collect flow records for every packet.

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.

Restrictions for Flexible NetFlow - Full Flow Support

  • The Microflow Policing feature shares the NetFlow hardware resource with Flexible NetFlow.
  • One flow monitor per interface, per direction, is supported.
  • Layer 2, IPv4 and IPv6 traffic types are supported. However, a flow monitor can be applied to only one of these types at a time for a given direction and interface.
  • Layer 2, VLAN, and Layer 3 interfaces are supported. Switched virtual interfaces and tunnels are not supported.
  • The Ingress and Egress NetFlow tables do not support LAN base license level.
  • The Ingress NetFlow table supports an IP base license level of 8K on a per Application Specific Integrated Circuit (ASIC) basis.
  • The Egress NetFlow table supports an IP base license level of 16K on a per ASIC basis.
  • The Ingress NetFlow table supports an IP services license level of 8K on a per ASIC basis.
  • The Egress NetFlow table supports an IP services license level of 16K on a per ASIC basis.
  • Depending on the switch type, Cisco Catalyst 3850 Series Switches have one or two forwarding ASICs.
  • The Cisco 5700 Wireless Controller supports three ASICs.
  • The NetFlow tables are on separate compartments and cannot be combined. Depending on which ASIC processed the packet, the flows will be created in the table in the corresponding ASIC.
  • Only full flow accounting is supported for wireless traffic.
  • For information about the fields supported by Flexible NetFlow, refer to the Cisco IOS Flexible NetFlow Command Reference.
  • NetFlow hardware uses hash tables internally. It is possible that hash collisions happen in the hardware. So, in spite of the internal overflow CAM, the actual NetFlow table utilization could be about 80%.
  • Depending on what fields are used for the flow, a single flow could take two consecutive entries. Also, IPv6 flows take two entries. So, for these cases, the effective usage of NetFlow entries is half the table size. This is apart from the hash collision limitation.

  • Up to 16 flow monitors are supported. Microflow policing uses a separate set of flow monitors.

  • Service Set Identifier (SSID)-based NetFlow accounting is supported. SSID is treated like an interface. However, fields like AP MAC address and user ID are not supported.
  • The NetFlow software supports distributed NetFlow export, so the flows are exported from the same switch in which the flow was created.

  • Ingress flows are present in the ASIC that first received the packets for the flow. Egress flows are present in the ASIC from which the packets actually left the switch setup.

  • The reported value for the bytes count field (IN_BYTES) is (layer-2-packet-size - 18 bytes). For classic Ethernet traffic, this field will be accurate. For all other Ethernet types, this field will not be accurate. Please use the "bytes Layer 2" field, which will always report the accurate Layer 2 packet size.

Information About Flexible NetFlow Full Flow support

Flexible NetFlow - Full Flow support Overview

The Flexible NetFlow - Full Flow support feature enables Flexible NetFlow to collect flow records for every packet.

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

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

How to Configure Flexible NetFlow Full Flow 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 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 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 Customized 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.

An advanced user can create a customized format using the flow record command.

Before You Begin

If you want to use a customized record instead of using one of the Flexible NetFlow predefined records, 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 | netflow-original | netflow {ipv4 | ipv6} record [peer]}

6.    cache {entries number | timeout {active | inactive | update} seconds | type {immediate | normal | permanent}}

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

8.    statistics packet protocol

9.    statistics packet size

10.    exporter exporter-name

11.    end

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

13.    show running-config flow monitor monitor-name


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 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
description description


Example:

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

 

(Optional) Creates a description for the flow monitor.

 
Step 5
record {record-name | netflow-original | netflow {ipv4 | ipv6} record [peer]}


Example:

Device(config-flow-monitor)# record FLOW-RECORD-1

 

Specifies the record for the flow monitor.

 
Step 6
cache {entries number | timeout {active | inactive | update} seconds | type {immediate | normal | permanent}}


Example:

Device(config-flow-monitor)# cache type normal

 

(Optional) Modifies the flow monitor cache parameters such as timeout values, number of cache entries, and the cache type.

  • The values for the keywords associated with the timeout keyword have no effect when the cache type is set to immediate.
 
Step 7
Repeat Step 6 as required to finish modifying the cache parameters for this flow monitor.  

--

 
Step 8
statistics packet protocol


Example:

Device(config-flow-monitor)# statistics packet protocol

 

(Optional) Enables the collection of protocol distribution statistics for Flexible NetFlow monitors.

 
Step 9
statistics packet size


Example:

Device(config-flow-monitor)# statistics packet size

 

(Optional) Enables the collection of size distribution statistics for Flexible NetFlow monitors.

 
Step 10
exporter exporter-name


Example:

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

 

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

 
Step 13
show running-config flow monitor monitor-name


Example:

Device# 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 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
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 Full Flow Support

Example: Configuring Full Flow Accounting for IPv4 and IPv6 Traffic

The following example shows how to configure Flexible NetFlow full flow 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
!
!
flow monitor FLOW-MONITOR-3
 record v4_r1
 exit
!
!
flow monitor FLOW-MONITOR-4
 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
 ip flow monitor FLOW-MONITOR-3 input
 ipv6 flow monitor FLOW-MONITOR-4 input
!

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 - Full Flow 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 - Full Flow support

Feature Name

Releases

Feature Information

Flexible NetFlow - Full Flow support

Cisco IOS XE Release 3.1S

Cisco IOS XE Release 3.2SE

This feature enables Flexible NetFlow to collect flow records for every packet.

No commands were introduced or modified by this feature.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

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