Contents
The Flexible Netflow Layer 2 Fields feature enables collecting statistics for Layer 2 fields such as MAC addresses and virtual LAN (VLAN) IDs from traffic.
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.
The Flexible Netflow--Layer 2 Fields feature enables collecting statistics for Layer 2 fields such as MAC addresses and virtual LAN (VLAN) IDs from traffic.
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.
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.
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. |
Command or Action | Purpose | |
---|---|---|
Step 1
|
enable
Example: Device> enable |
Enables privileged EXEC mode.
|
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.
|
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.
|
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. |
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.
Command or Action | Purpose | |
---|---|---|
Step 1
|
enable
Example: Device> enable |
Enables privileged EXEC mode.
|
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. |
The following example shows how to configure Flexible NetFlow for monitoring MAC and VLAN statistics.
This sample starts in global configuration mode:
! flow record LAYER-2-FIELDS-1 match ipv4 source address match ipv4 destination address match datalink dot1q vlan output match datalink mac source address input match datalink mac source address output match datalink mac destination address input match flow direction ! exit ! ! flow monitor FLOW-MONITOR-4 record LAYER-2-FIELDS-1 exit ! ip cef ! interface GigabitEthernet0/0/1 ip address 172.16.6.2 255.255.255.0 ip flow monitor FLOW-MONITOR-1 input !
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. |
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--Layer 2 Fields |
Feature Name |
Releases |
Feature Information |
---|---|---|
Flexible NetFlow--Layer 2 Fields |
12.2(33)SRE 12.4(22)T Cisco IOS XE Release 3.2SE |
Enables collecting statistics for Layer 2 fields such as MAC addresses and virtual LAN (VLAN) IDs from traffic. 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 datalink dot1q vlan , collect datalink mac, match datalink dot1q vlan, match datalink mac. |
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.