- Read Me First
- Flexible Netflow Overview
- Flexible NetFlow—IPv4 Unicast Flows
- Flexible NetFlow—IPv6 Unicast Flows
- Flexible NetFlow—MPLS Egress NetFlow
- Flexible NetFlow v9 Export Format
- Flexible NetFlow Output Features on Data Export
- Flexible NetFlow NetFlow V5 Export Protocol
- Using Flexible NetFlow Flow Sampling
- Flexible NetFlow - Layer 2 Fields
- Flexible Netflow - Ingress VRF Support
- Flexible NetFlow NBAR Application Recognition Overview
- Support for ISSU and SSO
- Flexible NetFlow IPFIX Export Format
- Flexible Netflow Export to an IPv6 Address
- Flexible Netflow—Egress VRF Support
- Flexible NetFlow - MPLS Support
- Flexible NetFlow—Prevent Export Storms
Flexible NetFlow Configuration Guide
- Updated:
- September 15, 2017
Chapter: Flexible NetFlow - Layer 2 Fields
Flexible NetFlow - Layer 2 Fields
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.
- Finding Feature Information
- Information About Flexible NetFlow Layer 2 Fields
- How to Configure Flexible NetFlow Layer 2 Fields
- Configuration Examples for Flexible NetFlow Layer 2 Fields
- Additional References
- Feature Information for Flexible NetFlow - Layer 2 Fields
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.
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.
Information About Flexible NetFlow Layer 2 Fields
Flexible NetFlow - Layer 2 Fields Overview
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.
How to Configure Flexible NetFlow Layer 2 Fields
Creating a 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.
1.
enable
2.
configure
terminal
3.
flow
record
record-name
4.
description
description
5.
match
{ip |
ipv6} {destination |
source}
address
6. Repeat Step 5 as required to configure additional key fields for the record.
7.
8. Repeat the above step 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
Creating a 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. These record formats can be a user-defined format. An advanced user can create a customized format using the flow record command.
If you want to use a customized record, 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. |
1.
enable
2.
configure
terminal
3.
flow
monitor
monitor-name
4.
description
description
5.
record {record-name}
6.
cache {timeout {active} seconds | {
normal
}
7. Repeat Step 6 as required to finish modifying the cache parameters for this flow monitor.
8.
exporter
exporter-name
9.
end
10.
show
flow
monitor
[[name]
monitor-name
[cache [format {csv |
record |
table}]]
]
11.
show
running-config
flow
monitor
monitor-name
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: > enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: # configure terminal |
Enters global configuration mode. |
| Step 3 |
flow
monitor
monitor-name
Example: (config)# flow monitor FLOW-MONITOR-1 |
Creates a flow monitor and enters Flexible NetFlow flow monitor configuration mode. |
| Step 4 |
description
description
Example: (config-flow-monitor)# description Used for basic ipv4 traffic analysis |
(Optional) Creates a description for the flow monitor. |
| Step 5 |
record {record-name} Example: (config-flow-monitor)# record FLOW-RECORD-1 |
Specifies the record for the flow monitor. |
| Step 6 |
cache {timeout {active} seconds | {
normal
} Example: |
|
| Step 7 | Repeat Step 6 as required to finish modifying the cache parameters for this flow monitor. |
— |
| Step 8 |
exporter
exporter-name
Example: (config-flow-monitor)# exporter EXPORTER-1 |
(Optional) Specifies the name of an exporter that was created previously. |
| Step 9 |
end
Example: (config-flow-monitor)# end |
Exits Flexible NetFlow flow monitor configuration mode and returns to privileged EXEC mode. |
| Step 10 |
show
flow
monitor
[[name]
monitor-name
[cache [format {csv |
record |
table}]]
]
Example: # show flow monitor FLOW-MONITOR-2 cache |
(Optional) Displays the status for a Flexible NetFlow flow monitor. |
| Step 11 |
show
running-config
flow
monitor
monitor-name
Example: # 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.
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.
|
| 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 Layer 2 Fields
Example: Configuring Flexible NetFlow for Monitoring MAC and VLAN Statistics
The following example shows how to configure Flexible NetFlow for monitoring MAC and VLAN statistics.
This example 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 !
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
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: |
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. |
Feature Information for Flexible NetFlow - Layer 2 Fields
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.|
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. |
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