Configuring NetFlow

A NetFlow flow is a unidirectional sequence of packets that arrive on a single interface, and have the same values for key fields.

NetFlow is useful for the following:

Accounting/Billing—NetFlow data provides fine grained metering for highly flexible and detailed resource utilization accounting.
Network Planning and Analysis—NetFlow data provides key information for strategic network planning.
Network Monitoring—NetFlow data enables near real-time network monitoring capabilities.

Prerequisites for Configuring NetFlow

To perform these configuration tasks, your Cisco IOS XR software system administrator must assign you to a user group associated with a task group that includes the corresponding command task IDs. If you need assistance with your task group assignment, contact your system administrator.

Restrictions for Configuring NetFlow

Consider these restrictions when configuring NetFlow in Cisco IOS XR software:

Tip

Do not use the management interface to export the NetFlow packets.

NetFlow can be configured only in the ingress direction.
A source interface must always be configured. If you do not configure a source interface, the exporter will remain in a disabled state.
Only export format Version 9 is supported.
A valid record map name must always be configured for every flow monitor map.
NetFlow on sub-interface routed via BVI is not supported.
Destination-based Netflow accounting is not supported, only IPv4, IPv6 and MPLS record types are supported under monitor-map.
Output interface field is not updated in data and flow records when the traffic is routed through ACL based forwarding (ABF).
Output interface field is not updated in data and flow records for the multicast traffic.
Output interface, source and destination prefix lengths fields are not set in data and flow records for GRE transit traffic.
In-line modification of NetFlow configuration is not supported.
For Netflow IPFIX315, configure the command.
If IPFIX315 is enabled on a line card then all the ports on that line card should have IPFIX315 configured.
For hw-module profile qos hqos-enable , NetFlow does not give the output interface for cases like L2 bridging, xconnect, IPFIX, and so on.
L4 header port numbers are supported only for TCP and UDP.
NetFlow does not give the output interface for traffic terminating on GRE tunnel.

Information About Configuring NetFlow

NetFlow Overview

A flow is exported as part of a NetFlow export User Datagram Protocol (UDP) datagram under these circumstances:

The flow has been inactive or active for too long.
The flow cache is getting full.
One of the counters (packets and or bytes) has wrapped.
The user forces the flow to export.

NetFlow export UDP datagrams are sent to an external flow collector device that provides NetFlow export data filtering and aggregation. The export of data consists of expired flows and control information.

The NetFlow infrastructure is based on the configuration and use of these maps:

Exporter map
Monitor map
Sampler map

These maps are described in the sections that follow.

Exporter Map Overview

An exporter map contains user network specification and transport layer details for the NetFlow export packet. The flow exporter-map command allows you to configure collector and version attributes. You can configure these collector information:

Export destination IP address
DSCP value for export packet
Source interface
UDP port number (This is where the collector is listening for NetFlow packets.)
Transport protocol for export packets

Note

In Cisco IOS XR Software, UDP is the only supported transport protocol for export packets.

Note

NetFlow export packets use the IP address that is assigned to the source interface. If the source interface does not have an IP address assigned to it, the exporter will be inactive.

You can also configure these export version attributes:

Template timeout
Template data timeout
Template options timeout
Interface table timeout
Sampler table timeout

Note

A single flow monitor map can support up to eight exporters.

Monitor Map Overview

A monitor map contains name references to the flow record map and flow exporter map. Monitor maps are applied to an interface. You can configure these monitor map attributes:

Number of entries in the flow cache
Type of cache (permanent or normal). Permanent caches do not have their entries removed from the cache unless they are explicitly cleared by the user
Active flow timeout
Inactive flow timeout
Update timeout
Default timeouts

Record type of packets sampled and collected

Note

The record name specifies the type of packets that NetFlow samples as they pass through the router. Currently, MPLS, IPv4, and IPv6 packet sampling is supported.

Note

The active flow and inactive flow timeouts are associated with a normal cache type. The update timeout is associated with the permanent cache type.

Sampler Map Overview

The sampler map specifies the interval at which packets (one out of n packets) are sampled. On high bandwidth interfaces, applying NetFlow processing to every single packet can result in significant CPU utilization. Sampler map configuration is typically geared towards such high speed interfaces.

Consider these points before applying sampler map:

You must remove the existing netflow configuration before applying a new sampler map on an already existing netflow interface configuration.
Sub-interfaces and physical interfaces under a port must have the same sampler map configuration.

Options Template Overview

NetFlow version 9 is a template-based version. The templates provide an extensible design to the record format. This feature allows enhancements to NetFlow services without requiring concurrent changes to the basic flow-record format. An options template is a special type of template record that is used to communicate the format of data related to the NetFlow process. Rather than supplying information about IP flows, the options are used to supply metadata about the NetFlow process itself. The sampler options template and the interface options template are different forms of options templates. These two tables are exported by the NetFlow process. The NetFlow process will also export the VRF table.

Sampler Table

The sampler options template consists of sampler tables. Similarly, the interface option templates consist of interface tables. By enabling the options for sampler table and interface table, it becomes easier for the collector to determine the information on data flow.

The sampler table consists of information on the active samplers. It is used by the collector to estimate the sampling rate for each data flow. The sampler table consists of the following information for each sampler:


Field Name	Value
FlowSamplerID	This ID is assigned to the sampler. It is used by the collector to retrieve information about the sampler for a data flow record.
FlowSamplerMode	This field indicates the mode in which the sampling has been performed.
FlowSamplerRandomInterval	This field indicates the rate at which the sampling is performed.
SamplerName	This field indicates the name of the sampler.

Interface Table

The interface table consists of information on interfaces that are being monitored for data flow. By using this information, the collector determines the names of interfaces associated with the data flow. The interface table consists of the following information:


Field Name	Value
ingressInterface	This field indicates the SNMP index assigned to the interface. By matching this value to the Ingress interface in the data flow record, the collector is able to retrieve the name of the interface.
interfaceDescription	This field indicates the name of the interface.

VRF Table

The VRF table consists of mapping of VRF IDs to the VRF names. By using this information, the collector determines the name of the required VRF. The VRF table consists of the following information:


Field Name	Value
ingressVRFID	The identifier of the VRF with the name in the VRF-Name field.
VRF-Name	The VRF name which has the VRFID value ingressVRFID. The value "default" indicates that the interface is not assigned explicitly to a VRF.

The data records contain ingressVRFID as an extra field in each record. The values of these fields are used to lookup the VRF Table to find the VRF names. A value 0 in these fields indicates that the VRF is unknown.

The VRF table is exported at intervals specified by the optional timeout keyword that can be configured manually. The default value is 1800 seconds.

NetFlow Configuration Submodes

In Cisco IOS XR Software, NetFlow map configuration takes place in map-specific submodes. Cisco IOS XR Software supports these NetFlow map configuration submodes:

Note

The Cisco IOS XR Software allows you to issue most commands available under submodes as one single command string from mode. For example, you can issue the record ipv4 command from the flow monitor map configuration submode as follows:


RP/0/RP0/CPU0:router(config)# flow monitor-map fmm
RP/0/RP0/CPU0:router(config-fmm)# record ipv4

Alternatively, you can issue the same command from global configuration mode, as shown in the following example:


RP/0/RP0/CPU0:router(config)# flow monitor-map fmm record ipv4

Flow Monitor Map Configuration Submode

When you issue the flow monitor-map map_name command in mode, the CLI prompt changes to “config-fmm,” indicating that you have entered the flow monitor map configuration submode.

In this sample output, the question mark (?) online help function displays all the commands available under the flow monitor map configuration submode:


RP/0/RP0/CPU0:router(config)# flow monitor-map fmm

RP/0/RP0/CPU0:router(config-fmm)# ?

cache     Specify flow cache attributes
commit    Commit the configuration changes to running
describe  Describe a command without taking real actions
do        Run an exec command
exit      Exit from this submode
exporter  Specify flow exporter map name
no        Negate a command or set its defaults
record    Specify a flow record map name
show      Show contents of configuration

Flow Exporter Map Configuration Submode

When you issue the flow exporter-map fem-name command in mode, the command-line interface (CLI) prompt changes to “config-fem,” indicating that you have entered the flow exporter map configuration submode.

In this sample output, the question mark (?) online help function displays all the commands available under the flow exporter map configuration submode:


RP/0/RP0/CPU0:router(config)# flow exporter-map fem

RP/0/RP0/CPU0:router(config-fem)# ? 

clear        Clear the uncommitted configuration
clear        Clear the configuration
commit       Commit the configuration changes to running
describe     Describe a command without taking real actions
destination  Export destination configuration
do           Run an exec command
dscp         Specify DSCP value for export packets
exit         Exit from this submode
no           Negate a command or set its defaults
pwd          Commands used to reach current submode
root         Exit to the global configuration mode
show         Show contents of configuration
source       Source interface
transport    Specify the transport protocol for export packets
version      Specify export version parameters

Note

If you enter the version command, you enter the flow exporter map version configuration submode.

Note

A single flow monitor map can support up to eight exporters.

Flow Exporter Map Version Configuration Submode

When you issue the version v9 command in the flow exporter map configuration submode, the CLI prompt changes to “config-fem-ver,” indicating that you have entered the flow exporter map version configuration submode.

In this sample output, the question mark (?) online help function displays all the commands available under the flow exporter map version configuration submode:


RP/0/RP0/CPU0:router(config-fem)# version v9

RP/0/RP0/CPU0:router(config-fem-ver)# ?

commit    Commit the configuration changes to running
describe  Describe a command without taking real actions
do        Run an exec command
exit      Exit from this submode
no        Negate a command or set its defaults
options   Specify export of options template
show      Show contents of configuration
template  Specify template export parameters

Sampler Map Configuration Submode

When you issue the sampler-map map_name command in mode, the CLI prompt changes to “config-sm,” indicating that you have entered the sampler map configuration submode.

In this sample output, the question mark (?) online help function displays all the commands available under the sampler map configuration submode:


RP/0/RP0/CPU0:router(config)# sampler-map fmm

RP/0/RP0/CPU0:router(config-sm)# ?
clear     Clear the uncommitted configuration
clear     Clear the configuration
commit    Commit the configuration changes to running
describe  Describe a command without taking real actions
do        Run an exec command
exit      Exit from this submode
no        Negate a command or set its defaults
pwd       Commands used to reach current submode
random    Use random mode for sampling packets
root      Exit to the global configuration mode
show      Show contents of configuration

Enabling the NetFlow BGP Data Export Function

Use the bgp attribute-download command to enable NetFlow BGP routing attribute collection. The routing attributes are then exported. When no routing attributes are collected, zeroes (0) are exported.

When BGP attribute download is enabled, BGP downloads the attribute information for prefixes (community, extended community, and as-path) to the Routing Information Base (RIB) and Forwarding Information Base (FIB). This enables FIB to associate the prefixes with attributes and send the NetFlow statistics along with the associated attributes.

MPLS Flow Monitor with IPv4 and IPv6 Support

Cisco IOS XR Software supports the NetFlow collection of MPLS packets. It also supports the NetFlow collection of MPLS packets carrying IPv4, IPv6, or both IPv4 and IPv6 payloads.

MPLS Cache Reorganization to Support Both IPv4 and IPv6

In Cisco IOS XR Software, at a time, you can have only one MPLS flow monitor running on an interface. If you apply an additional MPLS flow monitor to the interface, the new flow monitor overwrites the existing one.

You can configure the MPLS flow monitor to collect IPv4 fields, IPv6 fields, or IPv4-IPv6 fields. IPv4-IPv6 configuration collects both IPv4 and IPv6 addresses using one MPLS flow monitor. IPv4 configuration collects only IPv4 addresses. IPv6 configuration collects only IPv6 addresses.

The MPLS flow monitor supports up to 1,000,000 cache entries. NetFlow entries include these types of fields:

IPv4 fields
IPv6 fields
MPLS with IPv4 fields
MPLS with IPv6 fields

The maximum number of bytes per NetFlow cache entry is as follows:

IPv4–88 bytes per entry
IPv6–108 bytes per entry
MPLS with IPv4 fields–108 bytes per entry
MPLS with IPv6 fields–128 bytes per entry

Note

The different types of NetFlow entries are stored in separate caches. Consequently, the number of NetFlow entries on a line card can significantly impact the amount of available memory on the line card. Also, even though the sampling rate for IPv6 is the same as the sampling rate for IPv4, the CPU utilization for IPv6 is higher due to the longer keys used by the IPv6 fields.

MPLS Packets with IPv6 Flows

Table 1. Feature History Table
Feature Name	Release Information	Feature Description
MPLS top label type 4 for BGP Labeled Unicast traffic	Release 7.4.1	This feature is an enhancement to how Netflow MPLS records are verified. This feature allows the user to analyze the traffic types by providing more visibility on the granularity of the information. This feature helps you to monitor the traffic data. This feature introduces the new MPLS label type BGP. This label type is a field in the MPLS label that identifies the control protocol which allocates the top-of-stack label. MPLS label types enable verification of Netflow MPLS records.

The collection of IPv6 flows in MPLS packets is an option. The CPU uses 128 bytes for each IPv6 field. IPv6 flows may contain these types of information:

Source IP address
Destination IP address
Traffic class value
Layer 4 protocol number
Layer 4 source port number
Layer 4 destination port number
Flow ID
Header option mask

To collect the IPv6 fields in MPLS packets, you must activate the MPLS record type, ipv6-fields by running the record mpls ipv6-fields command. You can also specify the number of labels to be used for aggregation with this command.

How to Configure NetFlow on Cisco IOS XR Software

The steps that follow provide a general overview of NetFlow configuration:

Note

We recommend that you not use the default ethernet VLAN (VLAN-1) in any of your network configurations. Traffic tagged with VLAN-1 may cause conflicts with other configurations.

Procedure

Step 1

Create and configure an exporter map.

Step 2

Create and configure a monitor map and a sampler map.

Note

The monitor map must reference the exporter map you created in Step 1. If you do not apply an exporter-map to the monitor-map, the flow records are not exported, and aging is done according to the cache parameters specified in the monitor-map.

Step 3

Apply the monitor map and sampler map to an interface.

These steps are described in detail in these sections:

Configuring an Exporter Map

Configure an exporter map and apply it to the monitor map with the flow monitor-map map_name exporter map_name command. You can configure the exporter map prior to configuring the monitor map, or you can configure the monitor map first and then configure and apply an exporter map later on.

Note

Cisco IOS XR Software supports the configuration of a single collector only in the exporter map.

The steps that follow describe how to create and configure an exporter map and enable exporting of the sampler table or the interface table.

Procedure

Step 1	configure Example: `RP/0/RP0/CPU0:router#configure` Enters global configuration mode.
Step 2	flow exporter-map `map_name` Example: `RP/0/RP0/CPU0:router(config)#flow exporter-map expmap-dtxr2` Creates an exporter map, configures the exporter map name, and enters flow exporter map configuration mode.
Step 3	destination `hostname_or_IP_address` `[` vrf `vrf-name]` Example: `RP/0/RP0/CPU0:router(config-fem)# destination 1.76.31.1` Configures the export destination for the flow exporter map. The destination can be a hostname, a VRF, or an IPv4/IPv6 address.
Step 4	dscp `dscp_value` Example: `RP/0/RP0/CPU0:router(config-fem)# dscp 10` (Optional) Specifies the differentiated services codepoint (DSCP) value for export packets. Replace the `dscp_value` argument with a value in the range from 0 through 63.
Step 5	source `type interface-path-id` Example: `RP/0/RP0/CPU0:router(config-fem)# source Loopback 0` Specifies a source interface, in the format `type` `interface-path-id` .
Step 6	transport udp `port` Example: `RP/0/RP0/CPU0:router(config-fem)# transport udp 5999` (Optional) Specifies the destination port for UDP packets. Replace `port` with the destination UDP port value, in the range from 1024 through 65535.
Step 7	version v9 Example: `RP/0/RP0/CPU0:router(config-fem-ver)# version v9` (Optional) Enters flow exporter map version configuration submode.
Step 8	options {interface-table \| sampler-table \| vrf-table} [timeout `seconds`] Example: `RP/0/RP0/CPU0:router(config-fem-ver)# options sampler-table timeout 1800` (Optional) Configures the export timeout value for the sampler table. Replace `seconds` with the export timeout value, in the range from 1 through 604800 seconds. Default is 1800 seconds.
Step 9	template [data \| options] timeout `seconds` Example: `RP/0/RP0/CPU0:router(config-fem-ver)# template data timeout 600` (Optional) Configures the export period for data packets. Replace `seconds` with the export timeout value, in the range from 1 through 604800 seconds.
Step 10	commit
Step 11	exit Example: `RP/0/RP0/CPU0:router(config-fem-ver)# exit` Exits flow exporter map version configuration submode.
Step 12	exit Example: `RP/0/RP0/CPU0:router(config)# exit` Enters XR EXEC mode.
Step 13	show flow exporter-map `map_name` Example: RP/0/RP0/CPU0:router# show flow exporter-map expmap-dtxr2 Flow Exporter Map : expmap-dtxr2 ------------------------------------------------- Id : 1 DestinationIpAddr : 1.76.31.1 VRFName : default SourceIfName : Loopback0 SourceIpAddr : 10.200.58.1 DSCP : 10 TransportProtocol : UDP TransportDestPort : 5999 Export Version: 9 Common Template Timeout : 1800 seconds Options Template Timeout : 1800 seconds Data Template Timeout : 600 seconds Interface-Table Export Timeout : 1800 seconds Sampler-Table Export Timeout : 0 seconds VRF-Table Export Timeout : 0 seconds Displays exporter map data.

Example

This example shows how to create a new flow exporter map called “fem1,” which uses the version 9 (V9) export format for NetFlow export packets. The data template flow-set is inserted into the V9 export packets once every 10 minutes, and the options interface table flow-set is inserted into the V9 export packet. The export packets are sent to the flow collector destination 10.1.1.1, where the source address is identical to the interface IP address of Loopback 0. The UDP destination port is 1024, and the DSCP value is 10:


RP/0/RP0/CPU0:router(config)# flow exporter-map fem1 
RP/0/RP0/CPU0:router(config-fem)# destination 10.1.1.1
RP/0/RP0/CPU0:router(config-fem)# source Loopback 0
RP/0/RP0/CPU0:router(config-fem)# transport udp 1024
RP/0/RP0/CPU0:router(config-fem)# dscp 10
RP/0/RP0/CPU0:router(config-fem)# exit
RP/0/RP0/CPU0:router(config-fem)# version v9
RP/0/RP0/CPU0:router(config-fem-ver)# template data timeout 600
RP/0/RP0/CPU0:router(config-fem-ver)# options interface-table
RP/0/RP0/CPU0:router(config-fem-ver)# exit

Configuring a Sampler Map

Procedure

Step 1	configure Example: `RP/0/RSP0/CPU0:router#configure` Enters global configuration mode.
Step 2	sampler-map `map_name` Example: `RP/0/RP0/CPU0:router(config)# sampler-map onein8k RP/0/RP0/CPU0:router(config-sm)#` Creates a sampler map and enters sampler map configuration mode.
Step 3	random 1 out-of `sampling_interval` Example: `RP/0/RP0/CPU0:router(config-sm)# random 1 out-of 8000` Configures the sampling interval to use random mode for sampling packets. Replace the `sampling_interval` argument with a number, in the range from 1 through 65535 units.
Step 4	commit
Step 5	exit Example: `RP/0/RP0/CPU0:router(config-sm)# exit` Exits sampler map configuration mode and enters the XR Config mode.
Step 6	exit Example: `RP/0/RP0/CPU0:router(config)# exit` Exits the mode and enters XR EXEC mode.
Step 7	show sampler-map `map_name` Example: `RP/0/RP0/CPU0:router#show sampler-map onein8k Sampler Map : onein8k ------------------------------------------------- Id: 1 Mode: Random (1 out of 8000 Pkts)` Displays sampler map data.

Example

This example shows how to create a new sampler map called “fsm1,” which samples 1 out of 65535 packets:


RP/0/RP0/CPU0:router# sampler-map fsm1 
RP/0/RP0/CPU0:router(config-sm)# random 1 out-of 65535
RP/0/RP0/CPU0:router(config)# exit

Configuring a Monitor Map

Procedure

Step 1

configure

Example:

RP/0/RSP0/CPU0:router#configure

Enters global configuration mode.

Step 2

flow monitor-map map_name

Example:


RP/0/RP0/CPU0:router(config)# flow monitor-map fmm-ipv4-dtxr2
RP/0/RP0/CPU0:router(config-fmm)#

Creates a monitor map and configures a monitor map name and enters flow monitor map configuration submode.

Step 3

Do one of the following:

record ipv4
record ipv4 [peer as]
record ipv6
record mpls [labels number]
record mpls [ipv4-fields] [labels number]
record mpls [ipv6-fields] [labels number]
record mpls [ipv4-ipv6-fields] [labels number]

Example:


RP/0/RP0/CPU0:router(config-fmm)# record ipv4

Configures the flow record map name for IPv4, IPv6, or MPLS.

Use the record ipv4 command to configure the flow record map name for IPv4. By default, you collect and export the originating autonomous system (AS) numbers.
Use the record ipv4 [peer-as] command to record peer AS. Here, you collect and export the peer AS numbers.

Note

Ensure that the bgp attribute-download command is configured. Else, no AS is collected when the record ipv4 or record ipv4 peer-as command is configured.

Use the record ipv6 command to configure the flow record map name for IPv6.
Use the record mpls labels command with the number argument to specify the number of labels that you want to aggregate. By default, MPLS-aware NetFlow aggregates the top six labels of the MPLS label stack. The maximum value is 6.
Use the record mpls ipv4-fields command to collect IPv4 fields in the MPLS-aware NetFlow.
Use the record mpls ipv6-fields command to collect IPV6 fields in the MPLS-aware NetFlow.

Use the record mpls ipv4-ipv6-fields command to collect IPv4 and IPv6 fields in the MPLS-aware NetFlow.

Note

For the outbundlemember option to be effective; you must configure monitor-map as following:

flow monitor-map nfmpls
record mpls ipv4-ipv6-fields
option outbundlemember

Step 4

cache entries number

Example:


RP/0/RP0/CPU0:router(config-fmm)# cache entries 65535

(Optional) Configures the number of entries in the flow cache. Replace the number argument with the number of flow entries allowed in the flow cache, in the range from 4096 through 1000000.

The default number of cache entries is 65535.

Step 5

cache permanent

Example:


RP/0/RP0/CPU0:router(config-fmm)# flow monitor-map fmm cache permanent

(Optional) Disables removal of entries from flow cache.

Step 6

cache timeout {active timeout_value | inactive timeout_value | update timeout_value}

Example:


RP/0/RP0/CPU0:router(config-fmm)# cache timeout inactive 120

(Optional) Configures the active, inactive, or update flow cache timeout value.

The default timeout value for the inactive flow cache is 15 seconds.
The default timeout value for the active flow cache is 1800 seconds.
The default timeout value for the update flow cache is 1800 seconds.

Note

The update timeout_value keyword argument is used for permanent caches only. It specifies the timeout value that is used to export entries from permanent caches. In this case, the entries are exported but remain the cache.

Step 7

exporter map_name

Example:


RP/0/RP0/CPU0:router(config-fmm)# exporter expmap-dtxr2

Associates an exporter map with a monitor map.

Note

A single flow monitor map can support up to eight exporters.

Step 8

commit

Step 9

exit

Example:


RP/0/RP0/CPU0:router(config-fmm)# exit

Exits flow monitor map configuration submode.

Step 10

exit

Example:


RP/0/RP0/CPU0:router(config)# exit

Exits XR Config mode.

Step 11

show flow monitor-map map_name

Example:

RP/0/RP0/CPU0:router#show flow monitor-map fmm-ipv4-dtxr2
Flow Monitor Map : fmm-ipv4-dtxr2
-------------------------------------------------
Id:                1
RecordMapName:     ipv4-raw
ExportMapName:     expmap-dtxr2
CacheAgingMode:    Normal
CacheMaxEntries:   65535
CacheActiveTout:   60 seconds
CacheInactiveTout: 120 seconds
CacheUpdateTout:   N/A
CacheRateLimit:    2000

Displays flow monitor map data.

Example

This example shows how to create a new flow monitor map with name “fmm1”. This flow monitor map references the flow exporter map “fem1,” and sets the flow cache attributes to 10000 cache entries. The active entries from the cache are aged every 30 seconds, while the inactive entries from the cache are aged every 15 seconds. The record map for this monitor map is IPv4:


RP/0/RP0/CPU0:router(config)# flow monitor-map fmm1
RP/0/RP0/CPU0:router(config-fmm)# record ipv4
RP/0/RP0/CPU0:router(config-fmm)# exporter fem1
RP/0/RP0/CPU0:router(config-fmm)# cache entries 10000
RP/0/RP0/CPU0:router(config-fmm)# cache timeout active 30
RP/0/RP0/CPU0:router(config-fmm)# cache timeout inactive 15
RP/0/RP0/CPU0:router(config-fmm)# exit

Applying a Monitor Map and a Sampler Map to a Physical Interface

Perform these steps to apply a monitor map and a sampler map to an interface.

Procedure

Step 1

configure

Step 2

interface type number

Example:

RP/0/RP0/CPU0:router(config)# interface HundredGigE 0/4/0/8
RP/0/RP0/CPU0:router(config-if)#

Enters interface configuration mode.

Step 3

flow [ipv4 | ipv6 | mpls] monitor monitor_map sampler sampler_map {ingress}

Example:


RP/0/RP0/CPU0:router(config-if)# flow ipv4 monitor fmm sampler fsm ingress

Associates a monitor map and a sampler map with an interface.

Note

Only Ingress mode is supported.

Enter ipv4 to enable IPV4 NetFlow on the specified interface. Enter ipv6 to enable IPV6 NetFlow on the specified interface. Enter mpls to enable MPLS-aware NetFlow on the specified interface.

Step 4

commit

Example

This example shows how to apply the flow monitor “fmm1”and the sampler “fsm1” to the HundredGigE 0/3/0/0 interface in the ingress direction:

RP/0/RP0/CPU0:router(config)#interface HundredGigE 0/3/0/0
RP/0/RP0/CPU0:router(config-if)#flow ipv4 monitor fmm1 sampler fsm1 ingress 
RP/0/RP0/CPU0:router(config-if)#exit

This example shows how to apply the flow monitor “MPLS-IPv6-fmm”and the sampler “FSM” to the HundredGigE 0/3/0/0 interface in the ingress direction:

RP/0/RP0/CPU0:router(config)#interface HundredGigE 0/3/0/0
RP/0/RP0/CPU0:router(config-if)# flow mpls monitor MPLS-IPv6-fmm sampler FSM ingress
RP/0/RP0/CPU0:router(config-if)#exit

Clearing NetFlow Data

Procedure

Step 1

clear flow exporter [exporter_name] {restart | statistics} location node-id

Example:


RP/0/RP0/CPU0:router# clear flow exporter statistics location 0/0/CPU0

Clears the flow exporter data.

Specify the statistics option to clear exporter statistics. Specify the restart option to export all of the templates that are currently configured on the specified node.

Step 2

clear flow monitor [monitor_name] cache [force-export | statistics] location node-id}

Example:


RP/0/RP0/CPU0:router# clear flow monitor cache force-export location 0/0/CPU0

Clears the flow monitor data.

Specify the statistics option to clear cache statistics. Specify the force-export option to export the data from cache to server first and then clear the entries from cache.

Configure NetFlow Collection of MPLS Packets with IPv6 Fields

The following example shows how to collect MPLS traffic with IPv4 payloads.

Router(config)#flow monitor-map MPLS-IPv4-fmm
Router(config-fmm)#record mpls IPv4-fields labels 3
Router(config-fmm)#cache permanent
Router(config-fmm)#exit
Router(config)#interface HundredGigE 0/3/0/0
Router(config-if)#flow mpls monitor MPLS-IPv4-fmm sampler fsm ingress

The following example shows how to collect MPLS traffic with IPv6 payloads.

Router(config)#flow monitor-map MPLS-IPv6-fmm
Router(config-fmm)# record mpls IPv6-fields labels 3
Router(config-fmm)#cache permanent
Router(config-fmm)#exit
Router(config)#interface HundredGigE 0/3/0/0
Router(config-if)#flow mpls monitor MPLS-IPv6-fmm sampler fsm ingress

The following example shows how to configure the NetFlow monitor to collect MPLS packets with IPv6 fields:

Router# config
Router(config)# flow exporter-map exp1
Router(config-fem)#  version v9
Router(config-fem-ver)# options interface-table timeout 300
Router(config-fem-ver)# options sampler-table timeout 300
Router(config-fem-ver)# template data timeout 300
Router(config-fem-ver)# template options timeout 300
Router(config-fem-ver)# exit 
Router(config-fem)# transport udp 12515
Router(config-fem)# source Loopback0
Router(config-fem)# destination 170.1.1.11
Router(config-fmm)# exit
Router(config)# flow monitor-map MPLS-IPv6-fmm
Router(config-fmm)# record mpls ipv6-fields labels 3
Router(config-fmm)# exporter exp1
Router(config-fmm)# cache entries 10000
Router(config-fmm)# cache permanent
Router(config-fmm)# exit

Router(config)# sampler-map FSM
Router(config-sm)# random 1 out-of 65535
Router(config-sm)# exit
Router(config)# interface HundredGigE 0/3/0/0
Router(config-if)# flow mpls monitor MPLS-IPv6-fmm sampler FSM ingress

The following example shows how to collect MPLS traffic with both IPv6 and IPv4 fields.

Router(config)# flow monitor-map MPLS-IPv4-IPv6-fmm
Router(config-fmm)# record mpls IPv4-IPv6-fields labels 3
Router(config-fmm)# cache permanent
Router(config-fmm)# exit
Router(config)# interface HundredGigE 0/3/0/0
Router(config-if)# flow mpls monitor MPLS-IPv4-IPv6-fmm sampler fsm ingress

Note

Flow records are exported using the Version 9 format.

Running Configuration


/* This configuration collects MPLS traffic with IPv4 payloads. */
flow monitor-map MPLS-IPv4-fmm
 record mpls IPv4-fields labels 3
 cache permanent
exit
interface HundredGigE 0/3/0/0
 flow mpls monitor MPLS-IPv4-fmm sampler fsm ingress

/* This configuration collects MPLS traffic with IPv6 payloads. */
flow monitor-map MPLS-IPv6-fmm
 record mpls IPv6-fields labels 3
 cache permanent
exit
interface HundredGigE 0/3/0/0
 flow mpls monitor MPLS-IPv6-fmm sampler fsm ingress

/* This configuration collects MPLS packets with IPv6 fields */
flow exporter-map exp1
 version v9
  options interface-table timeout 300
  options sampler-table timeout 300
  template data timeout 300
  template options timeout 300
  exit 
  transport udp 12515
  source Loopback0
  destination 170.1.1.11
  exit
 flow monitor-map MPLS-IPv6-fmm
 record mpls ipv6-fields labels 3
 exporter exp1
 cache entries 10000
 cache permanent
 exit
sampler-map FSM
random 1 out-of 65535
 exit
 interface HundredGigE 0/3/0/0
 flow mpls monitor MPLS-IPv6-fmm sampler FSM ingress

/* This configuration collects MPLS traffic with both IPv6 and IPv4 fields */
flow monitor-map MPLS-IPv4-IPv6-fmm
 record mpls IPv4-IPv6-fields labels 3
 cache permanent
 exit
 interface HundredGigE 0/3/0/0
 flow mpls monitor MPLS-IPv4-IPv6-fmm sampler fsm ingress

Verification

Verify the flow monitor map data.

Router# show flow monitor-map MPLS-IPv6-fmm

Flow Monitor Map : MPLS-IPv6-fmm
-------------------------------------------------
Id:                1
RecordMapName:     ipv4-raw
ExportMapName:     expmap-dtxr2
CacheAgingMode:    Normal
CacheMaxEntries:   65535
CacheActiveTout:   60 seconds
CacheInactiveTout: 120 seconds
CacheUpdateTout:   N/A
CacheRateLimit:    2000

Verify the exporter map data.

Router# show flow exporter-map expmap-dtxr2 
Flow Exporter Map : expmap-dtxr2
-------------------------------------------------
Id                  : 1
DestinationIpAddr   : 170.1.1.11
VRFName             : default
SourceIfName        : Loopback0
SourceIpAddr        : 10.200.58.1
DSCP                : 10
TransportProtocol   : UDP
TransportDestPort   : 12515

Export Version: 9
   Common Template Timeout : 300 seconds
   Options Template Timeout : 300 seconds
   Data Template Timeout : 600 seconds
   Interface-Table Export Timeout : 300 seconds
   Sampler-Table Export Timeout : 0 seconds
   VRF-Table Export Timeout : 0 seconds

Verify the netflow cache record for MPLS packet.

Router# show flow monitor MPLS-IPv6-fmm cache format  record  location 0/0/CPU0
Thu Feb 25 05:14:11.474 IST
Cache summary for Flow Monitor FNF_MONITOR_MAP_MPLS2:
Cache size:                         256000
Current entries:                         1
Flows added:                            74
Flows not added:                         0
Ager Polls:                           4418
  - Active timeout                      73
  - Inactive timeout                     0
  - Immediate                            0
  - TCP FIN flag                         0
  - Emergency aged                       0
  - Counter wrap aged                    0
  - Total                               73
Periodic export:
  - Counter wrap                         0
  - TCP FIN flag                         0
Flows exported                          73
========== Record number: 1 ==========
LabelType        :       BGP
Prefix/Length    : ::/0                                        
Label1-EXP-S     :        0-0-0    
Label2-EXP-S     :    24026-0-1    
Label3-EXP-S     :       -         
Label4-EXP-S     :       -         
Label5-EXP-S     :       -         
Label6-EXP-S     :       -         
InputInterface   : BE100          
OutputInterface  : Hu0/0/0/3.1001 
ForwardStatus    : Fwd                 
FirstSwitched    : 00 06:33:48:047
LastSwitched     : 00 06:33:54:838
ByteCount        : 1002010     
PacketCount      : 1033        
Dir              : Ing
SamplerID        : 1         
IPv6SrcAddr      : 3001:10::2                              
IPv6DstAddr      : 1001:10::2                              
IPv6TC           : 0     
IPv6FlowLabel    : 7             
IPv6OptHdrs      : 0x10        
IPV6Prot         : 59      
L4SrcPort        : 0         
L4DestPort       : 0         
L4TCPFlags       : 0           
InputVRFID       : default                          
OutputVRFID      : default

Drop Codes on NetFlow

The following table lists supported drop codes on NetFlow:

Table 2. Drop Codes on NetFlow
Drop Reason(s)	IPFIX/V9 Code	sFlow Code
Unknown	128	256
ACL Deny	129	258
Adjacency	132	1
Bad Header Checksum	134	275
Bad TTL	137	257

Additional References

These sections provide references related to interface configuration.

Related Topic	Document Title
Cisco IOS XR interface configuration commands	Interface and Hardware Component Command Reference for Cisco NCS 5500 and NCS 540 and NCS 560 Series Routers
Initial system bootup and configuration information for a router using the Cisco IOS XR software.
Information about user groups and task IDs	Interface and Hardware Component Command Reference for Cisco NCS 5500 and NCS 540 and NCS 560 Series Routers
Information about configuring interfaces and other components from a remote Craft Works Interface (CWI) client management application.	Cisco Craft Works Interface User Guide

Standards


Standards	Title
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.	—

MIBs


MIBs	MIBs Link
—	Text for MIBs: To locate and download MIBs using Cisco IOS XR software, use the MIB Locator found at the Cisco Feature Navigator.

RFCs


RFCs	Title
3954	NetFlow services export protocol Version 9.
7011	IPFIX protocol

Netflow Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.5.x

Bias-Free Language

Results

Chapter: Configuring NetFlow

Configuring NetFlow

Prerequisites for Configuring NetFlow

Restrictions for Configuring NetFlow

Information About Configuring NetFlow

NetFlow Overview

Exporter Map Overview

Monitor Map Overview

Sampler Map Overview

Options Template Overview

Sampler Table

Interface Table

VRF Table

NetFlow Configuration Submodes

Flow Monitor Map Configuration Submode

Flow Exporter Map Configuration Submode

Flow Exporter Map Version Configuration Submode

Sampler Map Configuration Submode

Enabling the NetFlow BGP Data Export Function

MPLS Flow Monitor with IPv4 and IPv6 Support

MPLS Cache Reorganization to Support Both IPv4 and IPv6

MPLS Packets with IPv6 Flows

How to Configure NetFlow on Cisco IOS XR Software

Procedure

Configuring an Exporter Map

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Configuring a Sampler Map

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Configuring a Monitor Map

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Applying a Monitor Map and a Sampler Map to a Physical Interface

Procedure

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Clearing NetFlow Data

Procedure

Example:

Example:

Configure NetFlow Collection of MPLS Packets with IPv6 Fields

Running Configuration

Verification

Drop Codes on NetFlow

Additional References

Related Documents

Standards