IPv6 Implementation Guide, Cisco IOS Release 15.2M&T
Netflow v9 for IPv6
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Netflow v9 for IPv6

Netflow v9 for IPv6

Last Updated: July 31, 2012

This module contains information about and instructions for configuring NetFlow and NetFlow Data Export (NDE) for capturing and exporting data from IP version 6 (IPv6) traffic flows using the NetFlow version 9 (v9) export format.

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 Netflow v9 for IPv6

Your router must be running Cisco IOS release 12.2(33)SRB or later to configure the Netflow v9 for IPv6 feature.

Information About Netflow v9 for IPv6

NetFlow and NDE on the PFC

The NetFlow cache on the PFC captures statistics for flows routed in hardware.

The PFC uses one of these flow masks to create NetFlow entries:

  • source-only --The cache contains one entry for each source IP address. All flows from a given source IP address use this entry.
  • destination --The cache contains one entry for each destination IP address. All flows to a given destination IP address use this entry.
  • destination-source --The cache contains one entry for each source and destination IP address pair. All flows between the same source and destination IP addresses use this entry.
  • destination-source-interface --Adds the source VLAN SNMP ifIndex to the information in the destination-source flow mask.
  • full --A separate cache entry is created for each IP flow. A full entry includes the source IP address, destination IP address, protocol, and protocol interfaces.
  • full-interface --Adds the source VLAN SNMP ifIndex to the information in the full flow mask.

NetFlow Export Format Version 9

For all NetFlow export versions, the NetFlow export datagram consists of a header and a sequence of flow records. The header contains information such as sequence number, record count, and system uptime. The flow record contains flow information, such as IP addresses, ports, and routing information.

NetFlow version 9 export format is the newest NetFlow export format. The distinguishing feature of the NetFlow version 9 export format is that it is template based. Templates make the record format extensible. NetFlow version 9 export format allows future enhancements to NetFlow without requiring concurrent changes to the basic flow-record format.

The NetFlow version 9 export record format is different from the traditional NetFlow fixed format export record. In NetFlow version 9, a template describes the NetFlow data, and the flow set contains the actual data. This arrangement allows for flexible export.

The use of templates with the NetFlow version 9 export format provides several other key benefits:

  • You can export almost any information from a router or switch, including Layer 2 through 7 information, routing information, IP version 6 (IPv6), IP version 4 (IPv4), multicast, and Multiprotocol Label Switching (MPLS) information. This new information allows new applications for export data and new views of network behavior.
  • Third-party business partners who produce applications that provide NetFlow collector or display services for NetFlow are not required to recompile their applications each time a new NetFlow export field is added. Instead, they can use an external data file that documents the known template formats.
  • New features can be added to NetFlow more quickly, without breaking current implementations.
  • NetFlow is "future-proofed" against new or developing protocols, because the version 9 export format can be adapted to provide support for them and for other non-NetFlow-based approaches to data collection.

The NetFlow version 9 export packet header format is shown in the figure below.

Table 1 NetFlow Version 9 Export Packet Header Field Names and Descriptions


Field Name




The version of NetFlow records exported in this packet; for version 9, this value is 0x0009.



Number of FlowSet records (both template and data) contained within this packet.


System Uptime

Time in milliseconds since this device was first booted.


UNIX Seconds

Seconds since 0000 Coordinated Universal Time (UTC) 1970.


Sequence Number

Incremental sequence counter of all export packets sent by this export device; this value is cumulative, and it can be used to find out whether any export packets have been missed.

This is a change from the NetFlow version 5 and version 8 headers, where this number represented "total flows."


Source ID

The Source ID field is a 32-bit value that is used to guarantee uniqueness for each flow exported from a particular device. (The Source ID field is the equivalent of the engine type and engine ID fields found in the NetFlow version 5 and version 8 headers.) The format of this field is vendor specific. In Cisco's implementation, the first two bytes are reserved for future expansion and are always zero. Byte 3 provides uniqueness with respect to the routing engine on the exporting device. Byte 4 provides uniqueness with respect to the particular line card or Versatile Interface Processor on the exporting device. Collector devices should use the combination of the source IP address and the Source ID field to associate an incoming NetFlow export packet with a unique instance of NetFlow on a particular device.

The table below shows a typical example of exporting data using the NetFlow version 9 export format.

Figure 1 NetFlow Version 9 Export Format Packet Example

Additional information about the NetFlow export format version 9 and the export format architecture is available in the NetFlow version 9 Flow-Record Format document.

Configuring Netflow v9 for IPv6


1.    enable

2.    configure terminal

3.    ipv6 unicast-routing

4.    mls flow {ip | ipv6} {destination | destination-source | full | interface-destination-source | interface-full | source}

5.    mls nde sender

6.    ip flow-export version 9

7.    ip flow-export destination {ip-address | hostname} udp-port

8.    interface type number

9.    ipv6 address ip-address/mask

  Command or Action Purpose
Step 1


Router> enable


Enables privileged EXEC mode.

  • Enter your password if prompted.
Step 2
configure terminal


Router# configure terminal


Enters global configuration mode.

Step 3
ipv6 unicast-routing


Router(config)# ipv6 unicast-routing


Enables the forwarding of IPv6 unicast datagrams.

Step 4
mls flow {ip | ipv6} {destination | destination-source | full | interface-destination-source | interface-full | source}


Router(config)# mls flow ipv6 interface-full


Specifies the NetFlow flow mask for IPv6 traffic.

Step 5
mls nde sender


Route(config)# mls nde sender


Enables NDE globally on the router.

Note    NDE does not start exporting data until you specify a destination for the exported traffic. The destination for exported traffic is specified in Step 7.
Step 6
ip flow-export version 9


Router(config)# ip flow-export version 9


Configures NDE to use the NetFlow version 9 export format.

Step 7
ip flow-export destination {ip-address | hostname} udp-port


Router(config)# ip flow-export destination 88


Specifies the IP address or the hostname of the NetFlow collector and the UDP port on which the NetFlow collector is listening.

Step 8
interface type number


Router(config)# interface fastethernet 1/1


Specifies the interface that you want to enable NetFlow on and enters interface configuration mode.

Step 9
ipv6 address ip-address/mask


Router(config-if)# ipv6 address 2001:0DB8:AB::2/64


Configure an IPv6 address on the interface.



The following output of the show mls nde command verifies that NDE is enabled on the router.

Router# show mls nde
 NetFlow Data Export enabled 
 Exporting flows to (12345) (88)
 Exporting flows from (58970)
 Version: 9
 Layer2 flow creation is disabled
 Layer2 flow export is disabled
 Include Filter not configured 
 Exclude Filter not configured 
 Total NetFlow Data Export Packets are:
    0 packets, 0 no packets, 0 records
 Total NetFlow Data Export Send Errors:
        IPWRITE_NO_FIB = 0
 NetFlow Aggregation Disabled

Configuration Examples for Configuring Netflow v9 for IPv6

Example: Configuring the NetFlow v9 for IPv6 Feature

ipv6 unicast-routing
mls flow ipv6 interface-full 
mls nde sender 
ip flow-export version 9 
ip flow-export destination 88
interface FastEthernet1/1 
ipv6 address 

Additional References

Related Documents

Related Topic

Document Title

Platform-independent NetFlow commands, complete command syntax, command mode, defaults, command history, usage guidelines, and examples.

Cisco IOS NetFlow Command Reference

Command reference for Cisco 7600 series routers

Cisco 7600 Series Cisco IOS Command Reference




There are no standards associated with this feature.




MIBs Link

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





RFC 3954

Cisco Systems NetFlow Services Export Version 9

Technical Assistance



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Feature Information for Netflow v9 for IPv6

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 2 Feature Information for Netflow v9 for IPv6

Feature Name


Feature Information

Netflow v9 for IPv6


The Netflow v9 for IPv6 feature enables the export of NetFlow flow information for IPv6 traffic.

In 12.2(33)SRB, support for this feature was introduced on the Cisco 7600 series routers.

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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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