MPLS-aware NetFlow

吴贺华

MPLS-aware NetFlow

Feature Specifications for MPLS-aware NetFlow

Feature History  
Release  Modification  
12.0(24)S
This feature was introduced.

12.0(25)S
The no-ip-fields and mpls-length keywords were added to the ip flow-cache mpls label-positions command.

12.0(26)S
This feature was implemented on the Cisco 7200 and 7500 platforms and integrated into Cisco IOS 12.0(26)S. Support was added for the Cisco 12000 Series 8-Port OC-3 STM ATM line cards.

12.0(26)S1
Support was added for sampled MPLS-aware NetFlow on the Cisco 7200 and 7500 platforms.

Supported Platforms  
Cisco 7200 series, Cisco 7500 series, Cisco 12000 series (For specific line cards that support this feature, see Table 1.)

How to Configure MPLS-aware NetFlow SUMMARY STEPS 1. enable 2. configure terminal 3. interface type number 4. ip route-cache flow [sampled] 5. Repeat Steps 3 and 4 for each interface where you want to configure NetFlow accounting. 6. exit 7. ip flow-cache mpls label-positions [label-position-1 [label-position-2 [label-position-3]]] [no-ip-fields] [mpls-length] 8. exit

DETAILED STEPS

  Command or Action  Purpose  
Step 1   enable
Example:

Router> enable Enables privileged EXEC mode.

Enter your password if prompted.

Step 2   configure terminal
Example:

Router# configure terminal Enters global configuration mode.

Step 3   interface type number
Example:

Router(config)# interface pos 3/0 Configures an interface type and enters interface configuration mode.

The type argument indicates the type of interface to be configured.
The number argument is the port, connector, or interface card number. The numbers are assigned at the factory at the time of installation or when added to a system, and can be displayed with the show interfaces command.

Step 4   ip route-cache flow [sampled]
Example:

Router(config-if)# ip route-cache flow Enables NetFlow accounting on the interface.

The sampled keyword enables sampled NetFlow mode for IP and MPLS-aware NetFlow accounting.
Note For information on configuring a NetFlow sampler map required for sampling on Cisco 7500 and 7200 series routers, see the "Configuring Sampling for MPLS-aware NetFlow on Cisco 7500 and 7200 Platforms" section.

Step 5   Repeat Steps 3 and 4 for each interface where you want to configure NetFlow accounting.
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Step 6   exit
Example:

Router(config-if)# exit Exits to global configuration mode.

Step 7   ip flow-cache mpls label-positions [label-position-1 [label-position-2 [label-position-3]]] [no-ip-fields] [mpls-length]
Example:

Router(config)# ip flow-cache mpls label-positions 1 2 3 Enables MPLS-aware NetFlow.

The label-position-n argument identifies the position of an MPLS label of interest in the incoming label stack. Label positions are counted from the top of the stack, starting with 1.
The no-ip-fields keyword controls the capture and reporting of MPLS flow fields. If the no-ip-fields keyword is specified, the following IP-related flow fields are not included:
Source IP address
Destination IP address
Transport layer protocol
Source application port number
Destination application port number
IP type of service (ToS)
TCP flag (the result of a bitwise OR of TCP)
If the no-ip-fields keyword is not specified, the IP related fields are captured and reported.

The mpls-length keyword controls the reporting of packet length. If the mpls-length keyword is specified, the reported length represents the sum of the MPLS packet payload length and the MPLS label stack length.
If the mpls-length keyword is not specified, only the length of the MPLS packet payload is reported.

Step 8   exit
Example:

Router(config)# exit (Optional) Exits to privileged EXEC mode.
Configuring Sampling for MPLS-aware NetFlow on Cisco 7500 and 7200 Platforms
Perform this task to configure sampling for MPLS-aware NetFlow on Cisco 7500 and 7200 series platforms.

SUMMARY STEPS
1. enable

2. configure terminal

3. flow-sampler-map sampler-map-name

4. mode random one-out-of packet-interval

5. exit

6. interface type number

7. flow-sampler sampler-map-name

8. end

DETAILED STEPS

  Command or Action  Purpose  
Step 1   enable
Example:

Router> enable Enables privileged EXEC mode.

Enter your password if prompted.

Step 2   configure terminal
Example:

Router# configure terminal Enters global configuration mode.

Step 3   flow-sampler-map sampler-map-name
Example:

Router(config)# flow-sampler-map mysampler Defines a named object representing a NetFlow sampler.

The sampler-map-name argument is the name of the NetFlow sampler.

Step 4   mode random one-out-of packet-interval
Example:

Router(config-sampler-map)# mode random one-out-of 100 Specifies the sampling mode for the NetFlow sampler.

The random keyword specifies the random sampling mode.
The one-out-of packet-interval keyword argument combination defines the interval selected for random sampling. The packet interval is from 1 to 65535.

Step 5   exit
Example:

Router(config-sampler-map)# exit Exits to global configuration mode.

Step 6   interface type number
Example:

Router(config)# interface FastEthernet 2/0 Configures an interface type and enters interface configuration mode.

The type argument indicates the type of interface to be configured.
The number argument is the port, connector, or interface card number. The numbers are assigned at the factory at the time of installation or when added to a system, and can be displayed with the show interfaces command.

Step 7   flow-sampler sampler-map-name
Example:

Router(config-if)# flow-sampler mysampler Enables sampled NetFlow accounting on the interface.

The sampler-map-name argument is the name of the NetFlow sampler.

Step 8   end
Example:

Router(config-if)# end Exits to privileged EXEC mode.