Flexible NetFlow IPv4 Unicast Flows [Cisco Catalyst 3850 Series Switches]

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.

Flexible NetFlow--IPv4 Unicast Flows Overview

This feature enables Flexible NetFlow to monitor IPv4 traffic.

Configuring a Customized 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 {ipv4 | ipv6}{destination | source} address

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

7. collect interface {input | output}

8. Repeat Step 7 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 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 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 {ipv4 | ipv6}{destination | source} address

Example:

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

Configures a key field for the flow record.

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, refer to the Cisco IOS Flexible NetFlow Command Reference .

Step 6

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

--

Step 7

collect interface {input | output}

Example:

Device(config-flow-record)# collect interface input

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

Step 8

Repeat Step 7 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

To configure the flow exporter, perform the following required task.

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

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

7. dscp dscp

8. source interface-type interface-number

9. option {exporter-stats | interface-table | sampler-table| vrf-table} [timeout seconds]

10. output-features

11. template data timeout seconds

12. transport udp udp-port

13. ttl seconds

14. end

15. show flow exporter exporter-name

16. 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 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

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. The export of extracted fields from NBAR is supported only over IPFIX.

Default: netflow-v9.

Step 7

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 8

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 9

option {exporter-stats | interface-table | sampler-table| vrf-table} [timeout seconds]

Example:

Device(config-flow-exporter)# option exporter-stats timeout 120

(Optional) Configures options data parameters for the exporter.

You can configure all three options concurrently.
The range for the seconds argument is 1 to 86,400. Default: 600.

Step 10

output-features

Example:

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

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

Step 11

template data timeout seconds

Example:

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

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

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

Step 12

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 13

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 14

end

Example:

Device(config-flow-exporter)# end

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

Step 15

show flow exporter exporter-name

Example:

Device# show flow exporter FLOW_EXPORTER-1

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

Step 16

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.

Configuring a Flow Monitor for IPv4 or IPv6 Traffic Using the Predefined Record

To configure a flow monitor for IPv4/IPv6 traffic using the Flexible NetFlow "NetFlow IPv4/IPv6 original input" predefined record for the flow monitor, perform the following 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. description description

5. record netflow {ipv4 | ipv6} original-input

6. end

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

8. 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 monitoring IPv4 traffic	(Optional) Creates a description for the flow monitor.
Step 5	record netflow {ipv4 \| ipv6} original-input Example: Device(config-flow-monitor)# record netflow ipv4 original-input	Specifies the record for the flow monitor.
Step 6	end Example: Device(config-flow-monitor)# end	Exits Flexible NetFlow flow monitor configuration mode and returns to privileged EXEC mode.
Step 7	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 8	show running-config flow monitor monitor-name Example: Device# show 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.

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.

When you specify the "NetFlow original," or the "NetFlow IPv4 original input," or the "NetFlow IPv6 original input" predefined record for the flow monitor to emulate original NetFlow, the flow monitor can be used only for analyzing input (ingress) traffic.

When you specify the "NetFlow IPv4 original output" or the "NetFlow IPv6 original output" predefined record for the flow monitor to emulate the Egress NetFlow Accounting feature, the flow monitor can be used only for analyzing output (egress) traffic.

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 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	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 ethernet 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.

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 monitor FLOW-MONITOR-1
 record netflow ipv4 original-input
 exporter EXPORTER-2
 exporter EXPORTER-1
!
!
flow monitor FLOW-MONITOR-2
 record netflow ipv6 original-input
 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:

Router# show flow monitor FLOW-MONITOR-1
Flow Monitor FLOW-MONITOR-1:
  Description:       User defined
  Flow Record:       netflow original-input
  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 monitor FLOW-MONITOR-1
 record netflow ipv4 original-output
 exit
!
!
flow monitor FLOW-MONITOR-2
 record netflow ipv6 original-output
 exit
!
ip cef
ipv6 cef
!
interface Ethernet0/0
 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
!

Feature Information for Flexible NetFlow--IPv4 Unicast Flows

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 Unicast Flows

Feature Name

Releases

Feature Information

Flexible NetFlow--IPv4 Unicast Flows

12.2(33)SRC

12.2(50)SY

12.4(9)T

15.0(1)SY

15.0(1)SY1

Enables Flexible NetFlow to monitor IPv4 traffic.

Support for this feature was added for Cisco 7200 series routers in Cisco IOS Release 12.2(33)SRC.

The following commands were introduced or modified: collect routing, debug flow record, collect ipv4, collect ipv4 destination, collect ipv4 fragmentation, collect ipv4 section, collect ipv4 source, ip flow monitor, match ipv4, match ipv4 destination, match ipv4 fragmentation, match ipv4 section, match ipv4 source, match routing, record, show flow monitor, show flow record.

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.

Flexible NetFlow--IPv4 Unicast Flows

Finding Feature Information

Information About Flexible NetFlow IPv4 Unicast Flows

Flexible NetFlow--IPv4 Unicast Flows Overview

How to Configure Flexible NetFlow IPv4 Unicast Flows

Configuring a Customized Flow Record

Configuring the Flow Exporter

Creating a Customized Flow Monitor

Configuring a Flow Monitor for IPv4 or IPv6 Traffic Using the Predefined Record

Applying a Flow Monitor to an Interface

Configuring and Enabling Flexible NetFlow with Data Export

Configuration Examples for Flexible NetFlow IPv4 Unicast Flows

Example: Configuring Multiple Export Destinations

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

Feature Information for Flexible NetFlow--IPv4 Unicast Flows