Flexible Netflow Configuration Guide, Cisco IOS Release 15S

Flexible Netflow Configuration Guide, Cisco IOS Release 15S
Flexible Netflow Configuration Guide,
Cisco IOS Release 15S
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CONTENTS
Cisco IOS Flexible NetFlow Overview 1
Finding Feature Information 1
Information About Flexible NetFlow 1
Typical Uses for NetFlow 2
Use of Flows in Original NetFlow and Flexible NetFlow 2
Original NetFlow and Flexible NetFlow 3
Flexible NetFlow Components 4
Records 5
NetFlow Predefined Records 5
User-Defined Records 5
Flow Monitors 5
Flow Exporters 7
Flow Samplers 9
Security Monitoring with Flexible NetFlow 10
Feature Comparison of Original NetFlow and Flexible NetFlow 10
Limitations 13
Where to Go Next 13
Additional References 13
Getting Started with Configuring Cisco IOS Flexible NetFlow 15
Finding Feature Information 15
Prerequisites for Getting Started with Configuring Flexible NetFlow 16
Restrictions for Getting Started with Configuring Flexible NetFlow 16
Information About Getting Started with Configuring Flexible NetFlow 16
Benefit of Emulating Original NetFlow with Flexible NetFlow 16
NetFlow Original and NetFlow IPv4 Original Input Predefined Records 17
NetFlow IPv4 Original Output Predefined Record 18
NetFlow IPv6 Original Input Predefined Record 19
NetFlow IPv6 Original Output Predefined Record 21
Flexible NetFlow MPLS Egress NetFlow 22
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Contents
How to Get Started with Configuring Flexible NetFlow 23
Configuring a Flow Monitor for IPv4 or IPv6 Traffic Using the Predefined Record 24
Applying an IPv4 Flow Monitor to an Interface 25
Applying an IPv6 Flow Monitor to an Interface 27
Configuring a Flow Exporter for the Flow Monitor 29
Configuration Examples for Emulating Original NetFlow Features with Flexible NetFlow 31
Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6 Traffic 31
Example: Configuring Flexible NetFlow Subinterface Support 32
Example: Configuring Flexible NetFlow Multiple Export Destinations 32
Where to Go Next 33
Additional References 33
Feature Information for Flexible NetFlow 34
Configuring Cisco IOS Flexible NetFlow with Predefined Records 39
Finding Feature Information 39
Prerequisites for Flexible NetFlow with Predefined Records 39
Restrictions for Flexible NetFlow with Predefined Records 40
Information About Configuring Flexible NetFlow with Predefined Records 40
Flexible NetFlow Predefined Records 41
Benefits of Flexible NetFlow Predefined Records 41
NetFlow Original and NetFlow IPv4 Original Input Predefined Records 41
NetFlow IPv4 Original Output Predefined Record 42
NetFlow IPv6 Original Input Predefined Record 43
NetFlow IPv6 Original Input Predefined Record 45
Autonomous System Predefined Record 46
Autonomous System ToS Predefined Record 47
BGP Next-Hop Predefined Record 48
BGP Next-Hop ToS Predefined Record 49
Destination Prefix Predefined Record 50
Destination Prefix ToS Predefined Record 51
Prefix Predefined Record 52
Prefix Port Predefined Record 53
Prefix ToS Predefined Record 55
Protocol Port Predefined Record 56
Protocol Port ToS Predefined Record 57
Source Prefix Predefined Record 58
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Contents
Source Prefix ToS Predefined Record 59
How to Configure a Predefined Record for the Flow Monitor 60
Configuring a Flow Monitor for IPv4 Traffic Using a Predefined Record 60
Configuring a Flow Monitor for IPv6 Traffic Using a Predefined Record 62
Applying an IPv4 Flow Monitor to an Interface 64
Applying an IPv6 Flow Monitor to an Interface 65
Configuration Examples for Flexible NetFlow with Predefined Records 67
Example: Configuring a Flexible NetFlow Predefined Record for IPv4 Traffic 67
Example: Configuring a Flexible NetFlow Predefined Record for IPv6 Traffic 67
Where to Go Next 68
Additional References 68
Feature Information for Flexible NetFlow 69
Configuring Data Export for Flexible NetFlow with Flow Exporters 73
Finding Feature Information 73
Prerequisites for Data Export for Flexible NetFlow with Flow Exporters 73
Restrictions for Data Export for Flexible NetFlow with Flow Exporters 74
Information About Data Export for Flexible NetFlow with Flow Exporters 74
Flow Exporters 74
Benefits of Flexible NetFlow Flow Exporters 74
How to Configure Data Export for Flexible NetFlow with Flow Exporters 75
Restrictions 75
Configuring the Flow Exporter 75
Configuring and Enabling Flexible NetFlow with Data Export 79
Configuration Examples for Flexible NetFlow Data Export with Flow Exporters 81
Example: Configuring Multiple Export Destinations 81
Example: Configuring Sending Export Packets Using QoS 82
Example: Configuring Version 5 Export 83
Where to Go Next 83
Additional References 83
Feature Information for Flexible NetFlow 85
Customizing Flexible NetFlow Flow Records and Flow Monitors 91
Finding Feature Information 91
Prerequisites for Customizing Flexible NetFlow Flow Records and Flow Monitors 92
Information About Customizing Flexible NetFlow Flow Records and Flow Monitors 92
Criteria for Identifying Traffic To Be Used in Analysis in Flexible NetFlow 92
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Contents
How to Customize Flexible NetFlow Flow Records and Flow Monitors 93
Configuring a Customized Flow Record 94
Creating a Customized Flow Monitor 96
Applying a Flow Monitor to an Interface 98
Configuration Examples for Customizing Flow Records and Flow Monitors 100
Example: Configuring a Permanent Flow Record Cache with a Limited Number of Flows 100
Example: Configuring a Customized Flow Record Cache for Monitoring IPv6 Traffic 101
Example: Configuring Flexible NetFlow for Monitoring MAC and VLAN Statistics 102
Example: Configuring Flexible NetFlow for Ingress VRF Support 102
Example: Configuring Flexible NetFlow for Network-Based Application Recognition 103
Example: Configuring Flexible NetFlow for CTS Fields 103
Where to Go Next 104
Additional References 104
Feature Information for Flexible NetFlow 105
Using Flexible NetFlow Flow Sampling 111
Finding Feature Information 111
Prerequisites for Using Flow Sampling 111
Information About Flexible NetFlow Samplers 112
Flow Samplers 112
How to Configure Flexible NetFlow Flow Sampling 112
Configuring a Flow Monitor 112
Configuring and Enabling Flow Sampling 114
Configuration Examples for Using Flexible NetFlow Flow Sampling 116
Example: Configuring and Enabling a Deterministic Sampler for IPv4 Traffic 116
Example: Configuring and Enabling a Deterministic Sampler for IPv6 Traffic 117
Example: Adding a Sampler to a Flow Monitor When a Flow Monitor Is Already Enabled 117
Example: Removing a Sampler from a Flow Monitor 118
Additional References 118
Feature Information for Flexible Netflow—Random Sampling 119
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
NetFlow is a Cisco IOS technology that provides statistics on packets flowing through the router. NetFlow
is the standard for acquiring IP operational data from IP networks. NetFlow provides data to enable
network and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
This module provides an overview of Flexible NetFlow and the advanced Flexible NetFlow features and
services.
•
•
•
•
Finding Feature Information, page 1
Information About Flexible NetFlow, page 1
Where to Go Next, page 13
Additional References, page 13
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.
Information About Flexible NetFlow
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•
•
•
•
•
•
Typical Uses for NetFlow, page 2
Use of Flows in Original NetFlow and Flexible NetFlow, page 2
Original NetFlow and Flexible NetFlow, page 3
Flexible NetFlow Components, page 4
Security Monitoring with Flexible NetFlow, page 10
Feature Comparison of Original NetFlow and Flexible NetFlow, page 10
Limitations, page 13
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Typical Uses for NetFlow
Information About Flexible NetFlow
Typical Uses for NetFlow
NetFlow is typically used for several key customer applications, including the following:
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•
•
•
•
•
•
Network monitoring. NetFlow data enables extensive near-real-time network monitoring capabilities.
Flow-based analysis techniques are used by network operators to visualize traffic patterns associated
with individual routers and switches and network-wide traffic patterns (providing aggregate traffic or
application-based views) to provide proactive problem detection, efficient troubleshooting, and rapid
problem resolution.
Application monitoring and profiling. NetFlow data enables network managers to gain a detailed timebased view of application usage over the network. This information is used to plan, understand new
services, and allocate network and application resources (for example, web server sizing and VoIP
deployment) to meet customer demands responsively.
User monitoring and profiling. NetFlow data enables network engineers to gain detailed understanding
of customer and user use of network and application resources. This information may then be used to
efficiently plan and allocate access, backbone, and application resources and to detect and resolve
potential security and policy violations.
Network planning. NetFlow can be used to capture data over a long period of time, affording the
opportunity to track and anticipate network growth and plan upgrades to increase the number of
routing devices, ports, and higher-bandwidth interfaces. NetFlow services data optimizes network
planning for peering, backbone upgrades, and routing policy. NetFlow helps to minimize the total cost
of network operations while maximizing network performance, capacity, and reliability. NetFlow
detects unwanted WAN traffic, validates bandwidth and quality of service (QoS), and allows the
analysis of new network applications. NetFlow will give you valuable information to reduce the cost
of operating your network.
Security analysis. NetFlow identifies and classifies distributed denial of service (dDoS) attacks,
viruses, and worms in real time. Changes in network behavior indicate anomalies that are clearly
demonstrated in Flexible NetFlow data. The data is also a valuable forensic tool to understand and
replay the history of security incidents.
Billing and accounting. NetFlow data provides fine-grained metering (for instance, flow data includes
details such as IP addresses, packet and byte counts, time stamps, type of service (ToS), and
application ports) for highly flexible and detailed resource utilization accounting. Service providers
may use the information for billing based on time of day, bandwidth usage, application usage, quality
of service, and so on. Enterprise customers may use the information for departmental charge back or
cost allocation for resource utilization.
NetFlow data warehousing and data mining. NetFlow data (or derived information) can be warehoused
for later retrieval and analysis in support of proactive marketing and customer service programs (for
example, discovering which applications and services are being used by internal and external users and
targeting them for improved service, advertising, and so on). In addition, Flexible NetFlow data gives
market researchers access to the "who," "what," "where," and "how long" information relevant to
enterprises and service providers.
Use of Flows in Original NetFlow and Flexible NetFlow
Original NetFlow and Flexible NetFlow both use the concept of flows. A flow is defined as a stream of
packets between a given source and a given destination.
Original NetFlow and Flexible NetFlow both use the values in key fields in IP datagrams, such as the IP
source or destination address and the source or destination transport protocol port, as the criteria for
determining when a new flow must be created in the cache while network traffic is being monitored. When
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Original NetFlow and Flexible NetFlow
Information About Flexible NetFlow
the value of the data in the key field of a datagram is unique with respect to the flows that already exist, a
new flow is created.
Original NetFlow and Flexible NetFlow both use nonkey fields as the criteria for identifying fields from
which data is captured from the flows. The flows are populated with data that is captured from the values in
the nonkey fields.
The figure below is an example of the process for inspecting packets and creating flow records in the cache.
In this example, two unique flows are created in the cache because different values are in the source and
destination IP address key fields.
Figure 1
Packet Inspection
Original NetFlow and Flexible NetFlow
Original NetFlow uses a fixed seven tuples of IP information to identify a flow. Flexible NetFlow allows
the flow to be user defined. The benefits of Flexible NetFlow include:
•
•
•
•
•
High-capacity flow recognition, including scalability and aggregation of flow information.
Enhanced flow infrastructure for security monitoring and dDoS detection and identification.
New information from packets to adapt flow information to a particular service or operation in the
network. The flow information available will be customizable by Flexible NetFlow users.
Extensive use of Cisco’s flexible and extensible NetFlow Version 9 export format.
A comprehensive IP accounting feature that can be used to replace many accounting features, such as
IP accounting, Border Gateway Protocol (BGP) Policy Accounting, and persistent caches.
Original NetFlow allows you to understand the activities in the network and thus to optimize network
design and reduce operational costs. Flexible NetFlow allows you to understand network behavior with
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Flexible NetFlow Components
Information About Flexible NetFlow
more efficiency, with specific flow information tailored for various services used in the network. The
following are some example applications for a Flexible NetFlow feature:
•
•
•
Flexible NetFlow enhances Cisco NetFlow as a security monitoring tool. For instance, new flow keys
can be defined for packet length or MAC address, allowing users to search for a specific type of attack
in the network.
Flexible NetFlow allows you to quickly identify how much application traffic is being sent between
hosts by specifically tracking TCP or UDP applications by the class of service (CoS) in the packets.
The accounting of traffic entering a Multiprotocol Label Switching (MPLS) or IP core network and its
destination for each next hop per class of service. This capability allows the building of an edge-toedge traffic matrix.
The figure below is an example of how Flexible NetFlow might be deployed in a network.
Figure 2
Typical Deployment for Flexible NetFlow
Flexible NetFlow Components
Flexible NetFlow consists of components that can be used together in several variations to perform traffic
analysis and data export. The user-defined flow records and the component structure of Flexible NetFlow
facilitates the creation of various configurations for traffic analysis and data export on a networking device
with a minimum number of configuration commands. Each flow monitor can have a unique combination of
flow record, flow exporter, and cache type. If you change a parameter such as the destination IP address for
a flow exporter, it is automatically changed for all the flow monitors that use the flow exporter. The same
flow monitor can be used in conjunction with different flow samplers to sample the same type of network
traffic at different rates on different interfaces. The following sections provide more information on
Flexible NetFlow components:
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Records, page 5
Flow Monitors, page 5
Flow Exporters, page 7
Flow Samplers, page 9
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Records
Records
In Flexible NetFlow a combination of key and nonkey fields is called a record . Flexible NetFlow records
are assigned to Flexible NetFlow flow monitors to define the cache that is used for storing flow data.
Flexible NetFlow includes several predefined records that can help you get started using Flexible NetFlow.
To use Flexible NetFlow to its fullest potential, you need to create your own customized records, as
described in the following section(s):
•
•
NetFlow Predefined Records, page 5
User-Defined Records, page 5
NetFlow Predefined Records
Flexible NetFlow includes several predefined records that you can use to start monitoring traffic in your
network. The predefined records are available to help you quickly deploy Flexible NetFlow and are easier
to use than user-defined flow records. You can choose from a list of already defined records that may meet
the needs for network monitoring. As Flexible NetFlow evolves, popular user-defined flow records will be
made available as predefined records to make them easier to implement.
The predefined records ensure backward compatibility with your existing NetFlow collector configurations
for the data that is exported. Each of the predefined records has a unique combination of key and nonkey
fields that offer you the built-in ability to monitor various types of traffic in your network without
customizing Flexible NetFlow on your router.
Two of the predefined records (NetFlow original and NetFlow IPv4/IPv6 original output), which are
functionally equivalent, emulate original (ingress) NetFlow and the Egress NetFlow Accounting feature in
original NetFlow, respectively. Some of the other Flexible NetFlow predefined records are based on the
aggregation cache schemes available in original NetFlow. The Flexible NetFlow predefined records that are
based on the aggregation cache schemes available in original NetFlow do not perform aggregation. Instead
each flow is tracked separately by the predefined records.
User-Defined Records
Flexible NetFlow enables you to define your own records for a Flexible NetFlow flow monitor cache by
specifying the key and nonkey fields to customize the data collection to your specific requirements. When
you define your own records for a Flexible NetFlow flow monitor cache, they are referred to as userdefined records . The values in nonkey fields are added to flows to provide additional information about the
traffic in the flows. A change in the value of a nonkey field does not create a new flow. In most cases the
values for nonkey fields are taken from only the first packet in the flow. Flexible NetFlow enables you to
capture counter values such as the number of bytes and packets in a flow as nonkey fields.
Flexible NetFlow adds a new Version 9 export format field type for the header and packet section types.
Flexible NetFlow will communicate to the NetFlow collector the configured section sizes in the
corresponding Version 9 export template fields. The payload sections will have a corresponding length
field that can be used to collect the actual size of the collected section.
Flow Monitors
Flow monitors are the Flexible NetFlow component that is applied to interfaces to perform network traffic
monitoring.
Flow data is collected from the network traffic and added to the flow monitor cache during the monitoring
process based on the key and nonkey fields in the flow record.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Flow Monitors
Flexible NetFlow can be used to perform different types of analysis on the same traffic. In the figure below,
packet 1 is analyzed using a record designed for standard traffic analysis on the input interface and a record
designed for security analysis on the output interface.
Figure 3
Example of Using Two Flow Monitors to Analyze the Same Traffic
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Flow Exporters
The figure below shows a more complex example of how you can apply different types of flow monitors
with custom records.
Figure 4
Complex Example of Using Multiple Types of Flow Monitors with Custom Records
Normal
The default cache type is "normal." In this mode, the entries in the cache are aged out according to the
timeout active and timeout inactive settings. When a cache entry is aged out, it is removed from the cache
and exported via any exporters configured.
Flow Exporters
Flow exporters export the data in the flow monitor cache to a remote system, such as a server running
NetFlow collector, for analysis and storage. Flow exporters are created as separate entities in the
configuration. Flow exporters are assigned to flow monitors to provide data export capability for the flow
monitors. You can create several flow exporters and assign them to one or more flow monitors to provide
several export destinations. You can create one flow exporter and apply it to several flow monitors.
NetFlow Data Export Format Version 9
The basic output of NetFlow is a flow record. Several different formats for flow records have evolved as
NetFlow has matured. The most recent evolution of the NetFlow export format is known as Version 9. The
distinguishing feature of the NetFlow Version 9 export format is that it is template-based. Templates
provide an extensible design to the record format, a feature that should allow future enhancements to
NetFlow services without requiring concurrent changes to the basic flow-record format. Using templates
provides several key benefits:
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Flow Exporters
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•
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Third-party business partners who produce applications that provide collector or display services for
NetFlow do not have to recompile their applications each time a new NetFlow feature is added.
Instead, they should be able to use an external data file that documents the known template formats.
New features can be added to NetFlow quickly without breaking current implementations.
NetFlow is "future-proofed" against new or developing protocols because the Version 9 format can be
adapted to provide support for them.
The Version 9 export format consists of a packet header followed by one or more template flow or data
flow sets. A template flow set provides a description of the fields that will be present in future data flow
sets. These data flow sets may occur later within the same export packet or in subsequent export packets.
Template flow and data flow sets can be intermingled within a single export packet, as illustrated in the
figure below.
Figure 5
Version 9 Export Packet
NetFlow Version 9 will periodically export the template data so the NetFlow collector will understand what
data is to be sent and also export the data flow set for the template. The key advantage to Flexible NetFlow
is that the user configures a flow record, which is effectively converted to a Version 9 template and then
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Cisco IOS Flexible NetFlow Overview
Flow Samplers
forwarded to the collector. The figure below is a detailed example of the NetFlow Version 9 export format,
including the header, template flow, and data flow sets.
Figure 6
Detailed Example of the NetFlow Version 9 Export Format
For more information on the Version 9 export format, refer to the white paper titled Cisco IOS NetFlow
Version 9 Flow-Record Format, available at this URL: http://www.cisco.com/en/US/tech/tk648/tk362/
technologies_white_paper09186a00800a3db9.shtml .
Flow Samplers
Flow samplers are created as separate components in a router’s configuration. Flow samplers are used to
reduce the load on the device that is running Flexible NetFlow by limiting the number of packets that are
selected for analysis.
Flow sampling exchanges monitoring accuracy for router performance. When you apply a sampler to a
flow monitor, the overhead load on the router of running the flow monitor is reduced because the number
of packets that the flow monitor must analyze is reduced. The reduction in the number of packets that are
analyzed by the flow monitor causes a corresponding reduction in the accuracy of the information stored in
the flow monitor’s cache.
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Security Monitoring with Flexible NetFlow
Flow Samplers
Samplers are combined with flow monitors when they are applied to an interface with the ip flow monitor
command.
Security Monitoring with Flexible NetFlow
Flexible NetFlow can be used as a network attack detection tool with capabilities to track all parts of the IP
header and even packet sections and characterize this information into flows. Security monitoring systems
can analyze Flexible NetFlow data, and upon finding an issue in the network, create a virtual bucket or
virtual cache that will be configured to track specific information and identify details about the attack
pattern or worm propagation. The capability to create caches dynamically with specific information
combined with input filtering (for example, filtering all flows to a specific destination) makes Flexible
NetFlow a powerful security monitoring tool.
One common type of attack occurs when TCP flags are used to flood open TCP requests to a destination
server (for example, a SYN flood attack). The attacking device sends a stream of TCP SYNs to a given
destination address but never sends the ACK in response to the servers SYN-ACK as part of the TCP threeway handshake. The flow information needed for a security detection server requires the tracking of three
key fields: destination address or subnet, TCP flags, and packet count. The security detection server may be
monitoring general Flexible NetFlow information, and this data may trigger a detailed view of this
particular attack by the Flexible NetFlow dynamically creating a new flow monitor in the router’s
configuration. The new flow monitor might include input filtering to limit what traffic is visible in the
Flexible NetFlow cache along with the tracking of the specific information to diagnose the TCP-based
attack. In this case the user may want to filter all flow information to the server destination address or
subnet to limit the amount of information the security detection server needs to evaluate. If the security
detection server decided it understood this attack, it might then program another flow monitor to collect and
export payload information or sections of packets to take a deeper look at a signature within the packet.
This example is just one of many possible ways that Flexible NetFlow can be used to detect security
incidents.
Feature Comparison of Original NetFlow and Flexible NetFlow
The table below provides a feature-by-feature comparison of original NetFlow and Flexible NetFlow.
Table 1
Feature-by-Feature Comparison of Original NetFlow and Flexible NetFlow
Feature
Original NetFlow
Flexible NetFlow
Comments
NetFlow Data Capture
Supported
Supported
Data capture is available
with the predefined and
user-defined records in
Flexible NetFlow.
Flexible NetFlow has
several predefined keys
that emulate the traffic
analysis capabilities of
original NetFlow.
NetFlow Data Export
Supported
Supported
Flow exporters export
data from the Flexible
NetFlow flow monitor
caches to remote
systems.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Flow Samplers
Feature
Original NetFlow
Flexible NetFlow
Comments
NetFlow for IPv6
Supported
Supported
IPv6 support was
removed from original
NetFlow in Cisco IOS
Release 12.4(20)T.
The Flexible NetFlow-IPv6 Unicast Flows
feature implemented
IPv6 support for Flexible
NetFlow in Cisco IOS
Release 12.4(20)T.
MPLS-Aware NetFlow
Supported
Not supported
--
MPLS Egress NetFlow
Supported
Supported
The Flexible NetFlow-MPLS Egress NetFlow
feature implemented
MPLS NetFlow egress
support for Flexible
NetFlow in Cisco IOS
Release 12.4(22)T.
NetFlow BGP Next Hop Supported
Support
Supported
Available in the
predefined and userdefined keys in Flexible
NetFlow records.
Random Packet Sampled Supported
NetFlow
Supported
Available with Flexible
NetFlow sampling.
NetFlow v9 Export
Format
Supported
Supported
Available with Flexible
NetFlow exporters.
NetFlow Subinterface
Support
Supported
Supported
Flexible NetFlow
monitors can be assigned
to subinterfaces.
NetFlow Multiple
Export Destinations
Supported
Supported
Available with Flexible
NetFlow exporters.
NetFlow ToS-Based
Router Aggregation
Supported
Supported
Available in the
predefined and userdefined records in
Flexible NetFlow
records.
NetFlow Minimum
Prefix Mask for RouterBased Aggregation
Supported
Supported
Available in the
predefined and userdefined records.
NetFlow Input Filters
Supported
Not supported
--
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Cisco IOS Flexible NetFlow Overview
Flow Samplers
Feature
Original NetFlow
Flexible NetFlow
Comments
NetFlow MIB
Supported
Not supported
--
NetFlow MIB and Top
Talkers
Supported
Not supported
--
NetFlow Multicast
Support
Supported
Supported
In Cisco IOS Release
12.4(9)T through
12.4(20)T Flexible
NetFlow collects
statistics for multicast
flows. However, specific
additional fields such as
replication counts for
bytes and packets are not
supported.
The Flexible NetFlow-IPv4 Multicast Statistics
Support feature
implemented support for
capturing multicast
replication counts for
bytes and packets in
Cisco IOS Release
12.4(22)T.
NetFlow Layer 2 and
Security Monitoring
Exports
Supported
Partially supported
The Flexible NetFlow-Layer 2 Fields feature
implemented support for
capturing MAC
addresses and virtual
LAN (VLAN) IDs in
Cisco IOS Release
12.4(22)T.
Egress NetFlow
Accounting
Supported
Supported
Flexible NetFlow
monitors can be used to
monitor egress traffic on
interfaces and
subinterfaces.
NetFlow Reliable Export Supported
with SCTP
Not supported
--
NetFlow Dynamic Top
Talkers CLI
Supported
The Flexible NetFlow-Top N Talkers Support
feature implemented in
Cisco IOS Release
12.4(22)T provides the
same functionailty.
Supported
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
12
Limitations
Where to Go Next
Limitations
When using Flexible NetFlow to monitor outbound traffic on a router at the edge of an MPLS cloud, for IP
traffic that leaves over a VRF, the following fields are not collected and have a value of 0:
•
•
•
•
•
•
destination mask
destination prefix
destination AS numbers
destination BGP traffic index
nexthop
BGP nexthop
Where to Go Next
To implement a basic Flexible NetFlow configuration that emulates original NetFlow traffic analysis and
data export, refer to the "Getting Started with Configuring Cisco IOS Flexible NetFlow" module. To
implement other Flexible NetFlow configurations, refer to the Where to Go Next, page 13.
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Emulating original NetFlow with Flexible NetFlow
"Getting Started with Configuring Cisco IOS
Flexible NetFlow"
Configuring flow exporters to export Flexible
NetFlow data
"Configuring Data Export for Cisco IOS Flexible
NetFlow with Flow Exporters"
Customizing Flexible NetFlow for your network
"Customizing Cisco IOS Flexible NetFlow Flow
Records and Flow Monitors"
Configuring flow sampling to reduce the overhead
of monitoring traffic with Flexible NetFlow
"Using Cisco IOS Flexible NetFlow Flow Sampling
to Reduce the CPU Overhead of Analyzing Traffic"
Configuring Flexible NetFlow using predefined
records
"Configuring Cisco IOS Flexible NetFlow with
Predefined Records"
Using Flexible NetFlow Top N Talkers to analyze
network traffic
"Using Cisco IOS Flexible NetFlow Top N Talkers
to Analyze Network Traffic"
Configuring IPv4 multicast statistics support for
Flexible NetFlow
"Configuring IPv4 Multicast Statistics Support for
Cisco IOS Flexible NetFlow"
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
13
Cisco IOS Flexible NetFlow Overview
RFCs
RFC
Title
RFC 3954
Cisco Systems NetFlow Services Export Version 9
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.
http://www.cisco.com/cisco/web/support/
index.html
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 Configuration Guide, Cisco IOS Release 15S
14
Getting Started with Configuring Cisco IOS
Flexible NetFlow
This document contains information about and instructions for configuring Flexible NetFlow to emulate
the data capture, data analysis, and data export features of original NetFlow. The Flexible NetFlow
equivalents of some of the other features that have been added to original NetFlow, such as NetFlow
Subinterface Support and Multiple Export Destinations, are described in this document. The purpose of
this document is to help you start using Flexible NetFlow as quickly as possible, and explains how to
configure certain Flexible NetFlow features but does not explain them in detail. The documents listed in
the Getting Started with Configuring Cisco IOS Flexible NetFlow, page 15 contain more detailed
information on Flexible NetFlow features.
NetFlow is a Cisco IOS technology that provides statistics on packets flowing through the router. NetFlow
is the standard for acquiring IP operational data from IP networks. NetFlow provides data to support
network and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
•
•
•
•
•
•
•
•
•
Finding Feature Information, page 15
Prerequisites for Getting Started with Configuring Flexible NetFlow, page 16
Restrictions for Getting Started with Configuring Flexible NetFlow, page 16
Information About Getting Started with Configuring Flexible NetFlow, page 16
How to Get Started with Configuring Flexible NetFlow, page 23
Configuration Examples for Emulating Original NetFlow Features with Flexible NetFlow, page 31
Where to Go Next, page 33
Additional References, page 33
Feature Information for Flexible NetFlow, page 34
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 Configuration Guide, Cisco IOS Release 15S
15
Benefit of Emulating Original NetFlow with Flexible NetFlow
Prerequisites for Getting Started with Configuring Flexible NetFlow
Prerequisites for Getting Started with Configuring Flexible
NetFlow
•
•
You are familiar with the information in the " Cisco IOS Flexible NetFlow Overview " module.
The networking device must be running a Cisco IOS release that supports Cisco IOS Flexible
NetFlow.
IPv4 Traffic
•
•
The networking device must be configured for IPv4 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding .
IPv6 Traffic
•
•
The networking device must be configured for IPv6 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding
IPv6.
Restrictions for Getting Started with Configuring Flexible
NetFlow
•
•
Locally generated traffic (traffic that is generated by the router on which the Flexible NetFlow Output
Accounting feature is configured) is not counted as flow traffic for the Output Flexible NetFlow
Accounting feature.
The Flexible NetFlow Output Accounting feature counts CEF-switched packets only. Processswitched transit packets are not counted.
Information About Getting Started with Configuring Flexible
NetFlow
•
•
•
•
•
•
Benefit of Emulating Original NetFlow with Flexible NetFlow, page 16
NetFlow Original and NetFlow IPv4 Original Input Predefined Records, page 17
NetFlow IPv4 Original Output Predefined Record, page 18
NetFlow IPv6 Original Input Predefined Record, page 19
NetFlow IPv6 Original Output Predefined Record, page 21
Flexible NetFlow MPLS Egress NetFlow, page 22
Benefit of Emulating Original NetFlow with Flexible NetFlow
Emulating original NetFlow with Flexible NetFlow enables to you to deploy Flexible NetFlow quickly
because you can use a predefined record instead of designing and configuring a custom user-defined
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
16
NetFlow Original and NetFlow IPv4 Original Input Predefined Records
Information About Getting Started with Configuring Flexible NetFlow
record. You need only configure a flow monitor and apply it to an interface for Flexible NetFlow to start
working like original NetFlow. You can add an optional exporter if you want to analyze the data that you
collect with an application such as NetFlow collector.
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.
Flow exporters are used to send the data that you collect with Flexible NetFlow to a remote system such as
a NetFlow Collection Engine. Exporters use UDP as the transport protocol and use the Version 9 export
format.
If you are familiar with original NetFlow, you already understand the format and content of the data that
you collect and export with Flexible NetFlow when you emulate original NetFlow. You will be able to use
the same techniques for analyzing the data.
NetFlow Original and NetFlow IPv4 Original Input Predefined Records
The Flexible NetFlow "NetFlow original" and "NetFlow IPv4 original input" predefined records can be
used interchangeably because they have the same key and nonkey fields. The key and nonkey fields and the
counters for the Flexible NetFlow "NetFlow original" and "NetFlow IPv4 original input" predefined
records are shown in the table below.
Table 2
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow Original and NetFlow IPv4 Original
Input Predefined Records
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the type of service (ToS)
field.
IP Protocol
Key
Value in the IP protocol field.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Flow Sampler ID
Key
ID number of the flow sampler (if
flow sampling is enabled).
IP Source AS
Nonkey
Source autonomous system
number.
IP Destination AS
Nonkey
Destination autonomous system
number.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
17
NetFlow IPv4 Original Output Predefined Record
Information About Getting Started with Configuring Flexible NetFlow
Field
Key or Nonkey Field
Definition
IP Next Hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
TCP Flags
Nonkey
Value in the TCP flag field.
Interface Output
Nonkey
Interface on which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
The configuration in the How to Get Started with Configuring Flexible NetFlow, page 23 uses the
predefined Flexible NetFlow "NetFlow original" record.
NetFlow IPv4 Original Output Predefined Record
The Flexible NetFlow "NetFlow IPv4 original output" predefined record is used to emulate the original
NetFlow Egress NetFlow Accounting feature that was released in Cisco IOS Release 12.3(11)T. The key
and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv4 original output" predefined
record are shown in the table below.
Table 3
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv4 Original Output Predefined
Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Protocol
Key
Value in the IP protocol field.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
18
NetFlow IPv6 Original Input Predefined Record
Information About Getting Started with Configuring Flexible NetFlow
Field
Key or Nonkey Field
Definition
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Sampler ID
Key
ID number of the flow sampler (if
flow sampling is enabled).
IP Source AS
Nonkey
Source autonomous system
number.
IP Destination AS
Nonkey
Destination autonomous system
number.
IP Next Hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
TCP Flags
Nonkey
Value in the TCP flag field.
Interface Input
Nonkey
Interface on which the traffic is
received.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
The configuration in the Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6
Traffic, page 31 uses the predefined Flexible NetFlow "NetFlow original output" record.
NetFlow IPv6 Original Input Predefined Record
The key and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv6 original input"
predefined record are shown in the table below.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
19
Getting Started with Configuring Cisco IOS Flexible NetFlow
Information About Getting Started with Configuring Flexible NetFlow
Table 4
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv6 Original Input Predefined Record
Field
Key or NonKey Field
Definition
Traffic Class
Key
Value in the traffic class field.
Flow Label
Key
Flow label.
Protocol
Key
Value in the protocol field.
Extension Map
Key
Value in the extension map
bitmap.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Flow Direction
Key
The direction of the flow.
Flow Sampler
Key
ID number of the flow sampler (if
flow sampling is enabled).
Routing Source AS
Nonkey
Source autonomous system
number.
Routing Destination AS
Nonkey
Destination autonomous system
number.
Routing Next-hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
Transport TCP Flags
Nonkey
Value in the TCP flag field.
Interface Output
Nonkey
Interface over which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
20
NetFlow IPv6 Original Output Predefined Record
Information About Getting Started with Configuring Flexible NetFlow
Field
Key or NonKey Field
Definition
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
NetFlow IPv6 Original Output Predefined Record
The key and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv6 original output"
predefined record are shown in the table below.
Table 5
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv6 Original Output Predefined
Record
Field
Key or Nonkey Field
Definition
Traffic Class
Key
Value in the traffic class field.
Flow Label
Key
The flow label.
Protocol
Key
Value in the protocol field.
Extension Map
Key
Value in the extension map
bitmap.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Output
Key
Interface over which the traffic is
transmitted.
Flow Direction
Key
The direction of the flow.
Flow Sampler
Key
ID number of the flow sampler (if
flow sampling is enabled).
Routing Source AS
Nonkey
Source autonomous system
number.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
21
Flexible NetFlow MPLS Egress NetFlow
Information About Getting Started with Configuring Flexible NetFlow
Field
Key or Nonkey Field
Definition
Routing Destination AS
Nonkey
Destination autonomous system
number.
Routing Next-hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
Transport TCP Flags
Nonkey
Value in the TCP flag field.
Interface Input
Nonkey
Interface on which the traffic is
received.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Flexible NetFlow MPLS Egress NetFlow
The Flexible NetFlow--MPLS Egress NetFlow feature allows you to capture IP flow information for
packets that arrive on a router as Multiprotocol Label Switching (MPLS) packets and are transmitted as IP
packets. This feature allows you to capture the MPLS VPN IP flows that are traveling through the service
provider backbone from one site of a VPN to another site of the same VPN. The Flexible NetFlow--MPLS
Egress NetFlow feature is enabled by applying a flow monitor in output (egress) mode on the provider edge
(PE) to customer edge (CE) interface of the provider’s network.
The figure below shows a sample MPLS VPN network topology that includes four VPN 1 sites and two
VPN 2 sites. If the Flexible NetFlow--MPLS Egress NetFlow is enabled on an outgoing PE interface by
applying a flow monitor in output mode, IP flow information for packets that arrive at the PE as MPLS
packets (from an MPLS VPN) and that are transmitted as IP packets to the PE router is captured. For
example:
•
•
To capture the flow of traffic going to site 2 of VPN 1 from any remote VPN 1 sites, you enable a flow
monitor in output mode on link PE2-CE5 of provider edge router PE2.
To capture the flow of traffic going to site 1 of VPN 2 from any remote VPN 2 site, you enable a flow
monitor in output mode on link PE3-CE4 of the provider edge router PE3.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
22
Getting Started with Configuring Cisco IOS Flexible NetFlow
How to Get Started with Configuring Flexible NetFlow
The flow data is stored in the Flexible NetFlow cache. You can use the show flow monitor monitor-name
cachecommand to display the flow data in the cache.
Figure 7
Sample MPLS VPN Network Topology with Flexible NetFlow--MPLS Egress NetFlow Feature
If you configure a Flexible NetFlow exporter for the flow monitors you use for the Flexible NetFlow-MPLS Egress NetFlow feature, the PE routers will export the captured flows to the configured collector
devices in the provider network. Applications such as the Network Data Analyzer or the VPN Solution
Center (VPN-SC) can gather information from the captured flows and compute and display site-to-site
VPN traffic statistics.
How to Get Started with Configuring Flexible NetFlow
The tasks in this section explain how to configure and verify the emulation of original (ingress) NetFlow
data capture with Flexible NetFlow for traffic that is received by the router and how to configure and verify
the emulation of original NetFlow data export with Flexible NetFlow.
Note
Flexible NetFlow emulation of original NetFlow requires the configuration of a flow monitor and the
application of the flow monitor to at least one interface that is receiving the traffic that you want to analyze.
Note
Only the keywords and arguments required for the Flexible NetFlow commands used in these tasks are
explained in these tasks. For information on the other keywords and arguments available for these Flexible
NetFlow commands, refer to the Cisco IOS Flexible NetFlow Command Reference .
•
•
•
•
Configuring a Flow Monitor for IPv4 or IPv6 Traffic Using the Predefined Record, page 24
Applying an IPv4 Flow Monitor to an Interface, page 25
Applying an IPv6 Flow Monitor to an Interface, page 27
Configuring a Flow Exporter for the Flow Monitor, page 29
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
23
Configuring a Flow Monitor for IPv4 or IPv6 Traffic Using the Predefined Record
How to Get Started with Configuring Flexible NetFlow
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
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Example:
Device# configure terminal
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
24
Enters global configuration mode.
Applying an IPv4 Flow Monitor to an Interface
How to Get Started with Configuring Flexible NetFlow
Command or Action
Step 3 flow monitor monitor-name
Purpose
Creates a flow monitor and enters Flexible NetFlow
flow monitor configuration mode.
•
Example:
This command also allows you to modify an
existing flow monitor.
Device(config)# flow monitor FLOW-MONITOR-1
Step 4 description description
(Optional) Creates a description for the flow monitor.
Example:
Device(config-flow-monitor)# description Used for
monitoring IPv4 traffic
Step 5 record netflow {ipv4 | ipv6} original-input
Specifies the record for the flow monitor.
Example:
Device(config-flow-monitor)# record netflow ipv4
original-input
Step 6 end
Exits Flexible NetFlow flow monitor configuration
mode and returns to privileged EXEC mode.
Example:
Device(config-flow-monitor)# end
Step 7 show flow monitor [[name] monitor-name [cache [format {csv | (Optional) Displays the status and statistics for a
Flexible NetFlow flow monitor.
record | table}]][statistics]]
Example:
Device# show flow monitor FLOW-MONITOR-2 cache
Step 8 show running-config flow monitor monitor-name
(Optional) Displays the configuration of the specified
flow monitor.
Example:
Device# show flow monitor FLOW_MONITOR-1
Applying an IPv4 Flow Monitor to an Interface
Before it can be activated an IPv4 flow monitor must be applied to at least one interface. To activate an
IPv4 flow monitor, perform the following required task.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
25
Getting Started with Configuring Cisco IOS Flexible NetFlow
How to Get Started with Configuring Flexible NetFlow
Note
When you specify the "NetFlow original" or the "NetFlow IPv4 original input" predefined record for the
flow monitor to emulate original NetFlow, the flow monitor can be used for analyzing only input (ingress)
traffic.
When you specify the "NetFlow IPv4 original output" predefined record for the flow monitor to emulate
the Egress NetFlow Accounting feature, the flow monitor can be used for analyzing only output (egress)
traffic.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ip flow monitor monitor-name input
5. end
6. show flow interface type number
7. show flow monitor name monitor-name cache format record
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 interface type number
Specifies an interface and enters interface configuration
mode.
Example:
Router(config)# interface ethernet 0/0
Step 4 ip flow monitor monitor-name input
Example:
Router(config-if)# ip flow monitor FLOW-MONITOR-1
input
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
26
Activates the flow monitor that you created previously
by assigning it to the interface to analyze traffic.
Applying an IPv6 Flow Monitor to an Interface
How to Get Started with Configuring Flexible NetFlow
Command or Action
Purpose
Step 5 end
Exits interface configuration mode and returns to
privileged EXEC mode.
Example:
Router(config-if)# end
Step 6 show flow interface type number
Displays the status of Flexible NetFlow (enabled or
disabled) on the specified interface.
Example:
Router# show flow interface ethernet 0/0
Step 7 show flow monitor name monitor-name cache format record Displays the status, statistics, and flow data in the cache
for the specified flow monitor.
Example:
Router# show flow monitor name FLOW_MONITOR-1 cache
format record
Applying an IPv6 Flow Monitor to an Interface
Before it can be activated an IPv6 flow monitor must be applied to at least one interface. To activate an
IPv6 flow monitor, perform the following required task.
Note
When you specify the "NetFlow IPv6 original input" predefined record for the flow monitor to emulate
original NetFlow, the flow monitor can be used for analyzing only input (ingress) traffic.
When you specify the "NetFlow IPv6 original output" predefined record for the flow monitor to emulate
the Egress NetFlow Accounting feature, the flow monitor can be used for analyzing only output (egress)
traffic.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipv6 flow monitor monitor-name input
5. end
6. show flow interface type number
7. show flow monitor name monitor-name cache format record
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
27
Getting Started with Configuring Cisco IOS Flexible NetFlow
How to Get Started with Configuring Flexible NetFlow
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 interface type number
Specifies an interface and enters interface configuration
mode.
Example:
Router(config)# interface ethernet 0/0
Step 4 ipv6 flow monitor monitor-name input
Activates the flow monitor that you created previously
by assigning it to the interface to analyze traffic.
Example:
Router(config-if)# ipv6 flow monitor FLOW-MONITOR-2
input
Step 5 end
Exits interface configuration mode and returns to
privileged EXEC mode.
Example:
Router(config-if)# end
Step 6 show flow interface type number
Displays the status of Flexible NetFlow (enabled or
disabled) on the specified interface.
Example:
Router# show flow interface ethernet 0/0
Step 7 show flow monitor name monitor-name cache format record Displays the status, statistics, and flow data in the cache
for the specified flow monitor.
Example:
Router# show flow monitor name FLOW_MONITOR-1 cache
format record
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
28
Configuring a Flow Exporter for the Flow Monitor
How to Get Started with Configuring Flexible NetFlow
Configuring a Flow Exporter for the Flow Monitor
To configure a flow exporter for the flow monitor, in order to export the data that is collected by Flexible
NetFlow to a remote system for further analysis and storage, perform the following optional task.
Flow exporters are used to send the data that you collect with Flexible NetFlow to a remote system such as
a NetFlow Collection Engine. Exporters use UDP as the transport protocol and use the Version 9 export
format.
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 {hostname | ip-address} [vrf vrf-name]
6. export-protocol {netflow-v5 | netflow-v9 | ipfix}
7. transport udp udp-port
8. exit
9. flow monitor flow-monitor-name
10. exporter exporter-name
11. end
12. show flow exporter exporter-name
13. show running-config flow exporter exporter-name
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Getting Started with Configuring Cisco IOS Flexible NetFlow
How to Get Started with Configuring Flexible NetFlow
Command or Action
Step 3 flow exporter exporter-name
Example:
Purpose
Creates a flow exporter and enters Flexible NetFlow flow
exporter configuration mode.
•
This command also allows you to modify an existing
flow exporter.
Device(config)# flow exporter EXPORTER-1
Step 4 description description
(Optional) Creates a description for the flow exporter.
Example:
Device(config-flow-exporter)# description
Exports to datacenter
Step 5 destination {hostname | ip-address} [vrf vrf-name]
Example:
Specifies the hostname or IP address of the system to which
the exporter sends data.
Note You can export to a destination using either an IPv4 or
IPv6 address.
Device(config-flow-exporter)# destination
172.16.10.2
Step 6 export-protocol {netflow-v5 | netflow-v9 | ipfix}
Example:
Specifies the version of the NetFlow export protocol used by
the exporter.
•
Default: netflow-v9.
Device(config-flow-exporter)# export-protocol
netflow-v9
Step 7 transport udp udp-port
Configures UDP as the transport protocol and specifies the
UDP port on which the destination system is listening for
exported Flexible NetFlow traffic.
Example:
Device(config-flow-exporter)# transport udp 65
Step 8 exit
Exits Flexible NetFlow flow exporter configuration mode and
returns to global configuration mode.
Example:
Device(config-flow-exporter)# exit
Step 9 flow monitor flow-monitor-name
Example:
Device(config)# flow monitor FLOW-MONITOR-1
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
30
Enters Flexible NetFlow flow monitor configuration mode for
the flow monitor that you created previously.
Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6 Traffic
Configuration Examples for Emulating Original NetFlow Features with Flexible NetFlow
Command or Action
Step 10 exporter exporter-name
Purpose
Specifies the name of an exporter that you created previously.
Example:
Device(config-flow-monitor)# exporter
EXPORTER-1
Step 11 end
Exits Flexible NetFlow flow monitor configuration mode and
returns to privileged EXEC mode.
Example:
Device(config-flow-monitor)# end
Step 12 show flow exporter exporter-name
(Optional) Displays the current status of the specified flow
exporter.
Example:
Device# show flow exporter FLOW_EXPORTER-1
Step 13 show running-config flow exporter exporter-name
(Optional) Displays the configuration of the specified flow
exporter.
Example:
Device<# show running-config flow exporter
FLOW_EXPORTER-1
Configuration Examples for Emulating Original NetFlow
Features with Flexible NetFlow
•
•
•
Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6 Traffic, page 31
Example: Configuring Flexible NetFlow Subinterface Support, page 32
Example: Configuring Flexible NetFlow Multiple Export Destinations, page 32
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 sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 original-output
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
31
Example: Configuring Flexible NetFlow Subinterface Support
Configuration Examples for Emulating Original NetFlow Features with Flexible NetFlow
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
!
Example: Configuring Flexible NetFlow Subinterface Support
The following example shows how to configure Flexible NetFlow subinterface support for IPv4 traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 original-input
exit
!
ip cef
!
interface Ethernet0/0.1
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 input
!
The following example shows how to configure Flexible NetFlow to emulate NetFlow subinterface support
for IPv6 traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-2
record netflow ipv6 original-input
exit
!
ip cef
ipv6 cef
!
interface Ethernet0/0.1
ipv6 address 2001:DB8:2:ABCD::2/48
ipv6 flow monitor FLOW-MONITOR-2 input
!
Example: Configuring Flexible NetFlow Multiple Export Destinations
The following example shows how to configure Flexible NetFlow multiple export destinations.
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
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Getting Started with Configuring Cisco IOS Flexible NetFlow
Where to Go Next
transport udp 90
exit
!
flow monitor FLOW-MONITOR-1
record netflow-original
exporter EXPORTER-2
exporter EXPORTER-1
exit
!
ip cef
!
interface GigabitEthernet0/0/0
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 input
!
Where to Go Next
For information on advanced Flexible NetFlow configurations for specific purposes such as quality of
service (QoS) and bandwidth monitoring, application and user flow monitoring and profiling, and security
analysis, refer to the "Customizing Cisco IOS Flexible NetFlow Flow Records and Flow Monitors"
module.
If you want to configure additional options for data export for Flexible NetFlow, refer to the "Configuring
Data Export for Cisco IOS Flexible NetFlow with Flow Exporters" module.
If you want to configure flow sampling to reduce the CPU overhead of analyzing traffic, refer to the "Using
Cisco IOS Flexible NetFlow Flow Sampling to Reduce the CPU Overhead of Analyzing Traffic" module.
If you want to configure any of the predefined records for Flexible NetFlow refer, to the "Configuring
Cisco IOS Flexible NetFlow with Predefined Records" module.
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Overview of Flexible NetFlow
"Cisco IOS Flexible NetFlow Overview"
Configuring flow exporters to export Flexible
NetFlow data
"Configuring Data Export for Cisco IOS Flexible
NetFlow with Flow Exporters"
Customizing Flexible NetFlow
"Customizing Cisco IOS Flexible NetFlow Flow
Records and Flow Monitors"
Configuring flow sampling to reduce the overhead
of monitoring traffic with Flexible NetFlow
"Using Cisco IOS Flexible NetFlow Flow Sampling
to Reduce the CPU Overhead of Analyzing Traffic"
Configuring Flexible NetFlow using predefined
records
"Configuring Cisco IOS Flexible NetFlow with
Predefined Records"
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
33
Getting Started with Configuring Cisco IOS Flexible NetFlow
Feature Information for Flexible NetFlow
Related Topic
Document Title
Using Flexible NetFlow Top N Talkers to analyze
network traffic
"Using Cisco IOS Flexible NetFlow Top N Talkers
to Analyze Network Traffic"
Configuring IPv4 multicast statistics support for
Flexible NetFlow
"Configuring IPv4 Multicast Statistics Support for
Cisco IOS Flexible NetFlow"
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Standards
Standard
Title
None
--
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:
http://www.cisco.com/go/mibs
RFCs
RFC
Title
RFC 3954
Cisco Systems NetFlow Services Export Version 9
Technical Assistance
Description
Link
The Cisco Support and Documentation website
http://www.cisco.com/cisco/web/support/
provides online resources to download
index.html
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
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
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
34
Getting Started with Configuring Cisco IOS Flexible NetFlow
Feature Information for Flexible NetFlow
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.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
35
Getting Started with Configuring Cisco IOS Flexible NetFlow
Feature Information for Flexible NetFlow
Table 6
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow
12.2(33)SRC
Flexible NetFlow is introduced.
12.2(50)SY
Support for this feature was
added for Cisco 7200 series
routers in Cisco IOS Release
12.2(33)SRC.
12.4(9)T
15.0(1)SY
15.0(1)SY1
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
36
The following commands were
introduced or modified: cache
(Flexible NetFlow), clear flow
exporter, clear flow monitor,
clear sampler, collect counter,
collect flow, collect interface,
collect ipv4, collect ipv4
destination, collect ipv4
fragmentation, collect ipv4
section, collect ipv4 source,
collect ipv4 total-length, collect
ipv4 ttl, collect routing, collect
timestamp sys-uptime, collect
transport, collect transport
icmp ipv4, collect transport tcp,
collect transport udp, debug
flow exporter, debug flow
monitor, debug flow record,
debug sampler, description
(Flexible NetFlow), destination,
dscp (Flexible NetFlow),
exporter, flow exporter, flow
monitor, flow platform, flow
record, ip flow monitor, match
flow, match interface (Flexible
NetFlow), match ipv4, match
ipv4 destination, match ipv4
fragmentation, match ipv4
section, match ipv4 source,
match ipv4 total-length, match
ipv4 ttl, match routing, match
transport, match transport
icmp ipv4, match transport tcp,
match transport udp, mode
(Flexible NetFlow), option
(Flexible NetFlow), record,
sampler, show flow exporter,
show flow interface, show flow
monitor, show flow record,
show sampler, source (Flexible
NetFlow), statistics packet,
Getting Started with Configuring Cisco IOS Flexible NetFlow
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
template data timeout,
transport (Flexible NetFlow).
Flexible NetFlow--IPv6 Unicast
Flows
12.2(33)SRE
12.2(50)SY
12.4(20)T
15.0(1)SY
15.0(1)SY1
Enables Flexible NetFlow to
monitor IPv6 traffic.
Support for this feature was
added for Cisco 7200 and 7300
NPE series routers in Cisco IOS
Release 12.2(33)SRE.
The following commands were
introduced or modified: collect
routing, debug flow record,
match routing, record, show
flow monitor, show flow record,
collect ipv6, collect ipv6
destination, collect ipv6
extension map, collect ipv6
fragmentation, collect ipv6 hoplimit, collect ipv6 length, collect
ipv6 section, collect ipv6 source,
collect transport icmp ipv6,
ipv6 flow monitor, match ipv6,
match ipv6 destination, match
ipv6 extension map, match ipv6
fragmentation, match ipv6 hoplimit, match ipv6 length, match
ipv6 section, match ipv6 source,
match transport icmp ipv6.
Flexible NetFlow--MPLS Egress
NetFlow
12.2(33)SRE
12.2(50)SY
12.4(22)T
15.0(1)SY
15.0(1)SY1
The Flexible NetFlow--MPLS
Egress NetFlow feature allows
you to capture IP flow
information for packets
undergoing MPLS label
disposition; that is, packets that
arrive on a router as MPLS
packets and are transmitted as IP
packets.
Support for this feature was
added for Cisco 7200 and 7300
NPE series routers in Cisco IOS
Release 12.2(33)SRE.
No commands were introduced or
modified by this feature.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Getting Started with Configuring Cisco IOS Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow: Export to an
IPv6 Address
15.2(2)T
This feature enables Flexible
NetFlow to export data to a
destination using an IPv6 address.
The following commands were
introduced or modified:
destination
Flexible NetFlow: IPFIX Export
Format
15.2(4)M
Enables sending export packets
using the IPFIX export protocol.
The export of extracted fields
from NBAR is only supported
over IPFIX.
Support for this feature was
added for Cisco ASR 1000 Series
Aggregation Services routers in
Cisco IOS XE Release 3.7S.
The following command was
introduced: export-protocol.
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 Configuration Guide, Cisco IOS Release 15S
38
Configuring Cisco IOS Flexible NetFlow with
Predefined Records
This module contains information about and instructions for configuring Flexible NetFlow using
predefined records. Many of the Flexible NetFlow predefined records use the same key and nonkey fields
as the aggregation caches available in original NetFlow. However, the predefined Flexible NetFlow
records do not perform aggregation.
NetFlow is a Cisco IOS technology that provides statistics on packets flowing through a router. NetFlow
is the standard for acquiring IP operational data from IP networks. NetFlow provides data to support
network and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
•
•
•
•
•
•
•
•
•
Finding Feature Information, page 39
Prerequisites for Flexible NetFlow with Predefined Records, page 39
Restrictions for Flexible NetFlow with Predefined Records, page 40
Information About Configuring Flexible NetFlow with Predefined Records, page 40
How to Configure a Predefined Record for the Flow Monitor, page 60
Configuration Examples for Flexible NetFlow with Predefined Records, page 67
Where to Go Next, page 68
Additional References, page 68
Feature Information for Flexible NetFlow, page 69
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.
Prerequisites for Flexible NetFlow with Predefined Records
•
You are familiar with the information in the " Cisco IOS Flexible NetFlow Overview " module.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
39
Configuring Cisco IOS Flexible NetFlow with Predefined Records
Restrictions for Flexible NetFlow with Predefined Records
•
The networking device must be running a Cisco IOS release that supports Flexible NetFlow.
IPv4 Traffic
•
•
The networking device must be configured for IPv4 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding.
IPv6 Traffic
•
•
The networking device must be configured for IPv6 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding
IPv6.
Restrictions for Flexible NetFlow with Predefined Records
Cisco IOS Release 12.2(50)SY
•
Predefined records specifying mask and prefix are not supported.
Information About Configuring Flexible NetFlow with
Predefined Records
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Flexible NetFlow Predefined Records, page 41
Benefits of Flexible NetFlow Predefined Records, page 41
NetFlow Original and NetFlow IPv4 Original Input Predefined Records, page 41
NetFlow IPv4 Original Output Predefined Record, page 42
NetFlow IPv6 Original Input Predefined Record, page 43
NetFlow IPv6 Original Input Predefined Record, page 45
Autonomous System Predefined Record, page 46
Autonomous System ToS Predefined Record, page 47
BGP Next-Hop Predefined Record, page 48
BGP Next-Hop ToS Predefined Record, page 49
Destination Prefix Predefined Record, page 50
Destination Prefix ToS Predefined Record, page 51
Prefix Predefined Record, page 52
Prefix Port Predefined Record, page 53
Prefix ToS Predefined Record, page 55
Protocol Port Predefined Record, page 56
Protocol Port ToS Predefined Record, page 57
Source Prefix Predefined Record, page 58
Source Prefix ToS Predefined Record, page 59
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
40
Flexible NetFlow Predefined Records
Information About Configuring Flexible NetFlow with Predefined Records
Flexible NetFlow Predefined Records
Flexible NetFlow predefined records are based on the original NetFlow ingress and egress caches and the
aggregation caches. The difference between the original NetFlow aggregation caches and the corresponding
predefined Flexible NetFlow records is that the predefined records do not perform aggregation. Flexible
NetFlow predefined records are associated with a Flexible NetFlow flow monitor the same way that you
associate a user-defined (custom) record.
Benefits of Flexible NetFlow Predefined Records
If you have been using original NetFlow or original NetFlow with aggregation caches you can continue to
capture the same traffic data for analysis when you migrate to Flexible NetFlow by using the predefined
records available with Flexible NetFlow. Many users will find that the preexisting Flexible NetFlow
records are suitable for the majority of their traffic analysis requirements.
NetFlow Original and NetFlow IPv4 Original Input Predefined Records
The Flexible NetFlow "NetFlow original" and "NetFlow IPv4 original input" predefined records can be
used interchangeably because they have the same key and nonkey fields. The key and nonkey fields and the
counters for the Flexible NetFlow "NetFlow original" and "NetFlow IPv4 original input" predefined
records are shown in the table below.
Table 7
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow Original and NetFlow IPv4 Original
Input Predefined Records
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the type of service (ToS)
field.
IP Protocol
Key
Value in the IP protocol field.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Flow Sampler ID
Key
ID number of the flow sampler (if
flow sampling is enabled).
IP Source AS
Nonkey
Source autonomous system
number.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
41
NetFlow IPv4 Original Output Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IP Destination AS
Nonkey
Destination autonomous system
number.
IP Next Hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
TCP Flags
Nonkey
Value in the TCP flag field.
Interface Output
Nonkey
Interface on which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
The configuration in the How to Get Started with Configuring Flexible NetFlow, page 23 uses the
predefined Flexible NetFlow "NetFlow original" record.
NetFlow IPv4 Original Output Predefined Record
The Flexible NetFlow "NetFlow IPv4 original output" predefined record is used to emulate the original
NetFlow Egress NetFlow Accounting feature that was released in Cisco IOS Release 12.3(11)T. The key
and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv4 original output" predefined
record are shown in the table below.
Table 8
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv4 Original Output Predefined
Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Protocol
Key
Value in the IP protocol field.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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NetFlow IPv6 Original Input Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Sampler ID
Key
ID number of the flow sampler (if
flow sampling is enabled).
IP Source AS
Nonkey
Source autonomous system
number.
IP Destination AS
Nonkey
Destination autonomous system
number.
IP Next Hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
TCP Flags
Nonkey
Value in the TCP flag field.
Interface Input
Nonkey
Interface on which the traffic is
received.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
The configuration in the Example: Configuring Flexible NetFlow Egress Accounting for IPv4 and IPv6
Traffic, page 31 uses the predefined Flexible NetFlow "NetFlow original output" record.
NetFlow IPv6 Original Input Predefined Record
The key and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv6 original input"
predefined record are shown in the table below.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
43
Configuring Cisco IOS Flexible NetFlow with Predefined Records
Information About Configuring Flexible NetFlow with Predefined Records
Table 9
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv6 Original Input Predefined Record
Field
Key or NonKey Field
Definition
Traffic Class
Key
Value in the traffic class field.
Flow Label
Key
Flow label.
Protocol
Key
Value in the protocol field.
Extension Map
Key
Value in the extension map
bitmap.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Flow Direction
Key
The direction of the flow.
Flow Sampler
Key
ID number of the flow sampler (if
flow sampling is enabled).
Routing Source AS
Nonkey
Source autonomous system
number.
Routing Destination AS
Nonkey
Destination autonomous system
number.
Routing Next-hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
Transport TCP Flags
Nonkey
Value in the TCP flag field.
Interface Output
Nonkey
Interface over which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
44
NetFlow IPv6 Original Input Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or NonKey Field
Definition
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
NetFlow IPv6 Original Input Predefined Record
The key and nonkey fields and the counters for the Flexible NetFlow "NetFlow IPv6 original input"
predefined record are shown in the table below.
Table 10
Key and Nonkey Fields Used by the Flexible NetFlow NetFlow IPv6 Original Input Predefined Record
Field
Key or NonKey Field
Definition
Traffic Class
Key
Value in the traffic class field.
Flow Label
Key
Flow label.
Protocol
Key
Value in the protocol field.
Extension Map
Key
Value in the extension map
bitmap.
IP Source Address
Key
IP source address.
IP Destination Address
Key
IP destination address.
Transport Source Port
Key
Value of the transport layer
source port field.
Transport Destination Port
Key
Value of the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Flow Direction
Key
The direction of the flow.
Flow Sampler
Key
ID number of the flow sampler (if
flow sampling is enabled).
Routing Source AS
Nonkey
Source autonomous system
number.
Routing Destination AS
Nonkey
Destination autonomous system
number.
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
45
Autonomous System Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or NonKey Field
Definition
Routing Next-hop Address
Nonkey
IP address of the next hop.
IP Source Mask
Nonkey
Mask for the IP source address.
IP Destination Mask
Nonkey
Mask for the IP destination
address.
Transport TCP Flags
Nonkey
Value in the TCP flag field.
Interface Output
Nonkey
Interface over which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Autonomous System Predefined Record
The Flexible NetFlow "autonomous system" predefined record creates flows based on autonomous systemto-autonomous system traffic flow data. The Flexible NetFlow "autonomous system" predefined record
uses the same key and nonkey fields as the original NetFlow "autonomous system" aggregation cache.
Note
This predefined record can be used to analyze IPv4 and IPv6 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "autonomous system"
predefined record.
Table 11
Key and Nonkey Fields Used by the Flexible NetFlow Autonomous System Predefined Record
Field
Key or Nonkey Field
Definition
IP Source AS
Key
Autonomous system of the source
IP address (peer or origin).
IP Destination AS
Key
Autonomous system of the
destination IP address (peer or
origin).
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Autonomous System ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds since this device
was first booted) when the last
packet was switched.
Nonkey
Autonomous System ToS Predefined Record
The Flexible NetFlow "autonomous system ToS" predefined record creates flows based on autonomous
system-to-autonomous system and type of service (ToS) traffic flow data. The Flexible NetFlow
"autonomous system ToS" predefined record uses the same key and nonkey fields as the original NetFlow
"autonomous system ToS" aggregation cache.
Note
Tip
This predefined record can be used to analyze only IPv4 traffic.
This predefined record is particularly useful for generating autonomous system-to-autonomous system
traffic flow data.
The table below lists the key and nonkey fields used in the Flexible NetFlow "autonomous system ToS"
predefined record.
Table 12
Key and Nonkey Fields Used by the Flexible NetFlow Autonomous System ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
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BGP Next-Hop Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
BGP Next-Hop Predefined Record
The Flexible NetFlow "BGP next-hop" predefined record creates flows based on Border Gateway Protocol
(BGP) traffic flow data.
Note
This predefined record can be used to analyze only IPv6 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "BGP next-hop" predefined
record.
Table 13
Key and Nonkey Fields Used by the Flexible NetFlow BGP Next-Hop Predefined Record
Field
Key or Nonkey Field
Definition
Routing Source AS
Key
Autonomous system of the source
IP address.
Routing Destination AS
Key
Autonomous system of the
destination IP address.
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BGP Next-Hop ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Routing Next-hop Address IPv6
BGP
Key
IPv6 address of the BGP next
hop.
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Timestamp Sys-uptime First
Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Timestamp Sys-uptime Last
Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
BGP Next-Hop ToS Predefined Record
The Flexible NetFlow "BGP next-hop ToS" predefined record creates flows based on BGP and ToS traffic
flow data. The Flexible NetFlow "BGP next-hop ToS" predefined record uses the same key and nonkey
fields as the original NetFlow "BGP next-hop ToS" aggregation cache.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the "BGP next-hop ToS" predefined record.
Table 14
Key and Nonkey Fields Used by the Flexible NetFlow BGP Next-Hop ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
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Destination Prefix Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IPv4 Next Hop Address BGP
Key
IPv4 address of the BGP next
hop.
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Destination Prefix Predefined Record
The Flexible NetFlow "destination prefix" predefined record creates flows based on destination prefix
traffic flow data. The Flexible NetFlow "destination prefix" predefined record uses the same key and
nonkey fields as the original NetFlow "destination prefix" aggregation cache.
Note
This predefined record can be used to analyze IPv4 and IPv6 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "destination prefix"
predefined record.
Table 15
Key and Nonkey Fields Used by the Flexible NetFlow Destination Prefix Predefined Record
Field
Key or Nonkey Field
Definition
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
IPv4 or IPv6 Destination Prefix
Key
Destination IP address ANDed
with the destination prefix mask.
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Destination Prefix ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IPv4 or IPv6 Destination Mask
Key
Number of bits in the destination
prefix.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Destination Prefix ToS Predefined Record
The Flexible NetFlow "destination prefix ToS" predefined record creates flows based on destination prefix
and ToS traffic flow data. The Flexible NetFlow "destination prefix ToS" predefined record uses the same
key and nonkey fields as the original NetFlow "destination prefix ToS" aggregation cache.
This predefined record is particularly useful for capturing data with which you can examine the destinations
of network traffic passing through a NetFlow-enabled device.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "destination prefix ToS"
predefined record.
Table 16
Key and Nonkey Fields Used by the Flexible NetFlow Destination Prefix ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
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Prefix Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IPv4 Destination Prefix
Key
Destination IP address ANDed
with the destination prefix mask.
IPv4 Destination Mask
Key
Number of bits in the destination
prefix.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Prefix Predefined Record
The Flexible NetFlow "prefix" predefined record creates flows based on the source and destination prefixes
in the traffic flow data. The Flexible NetFlow "prefix" predefined record uses the same key and nonkey
fields as the original NetFlow "prefix" aggregation cache.
Note
This predefined record can be used to analyze IPv4 and IPv6 traffic. For IPv6 traffic, a minimum prefix
mask length of 0 bits is assumed.
The table below lists the key and nonkey fields used in the Flexible NetFlow "prefix" predefined record.
Table 17
Key and Nonkey Fields Used by the Flexible NetFlow Prefix Predefined Record
Field
Key or Nonkey Field
Definition
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
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Prefix Port Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
IPv4 or IPv6 Source Prefix
Key
Source IP address ANDed with
the source prefix mask, or the
prefix to which the source IP
address of the aggregated flows
belongs.
IPv4 or IPv6 Source Mask
Key
Number of bits in the source
prefix.
IPv4 or IPv6 Destination Prefix
Key
Destination IP address ANDed
with the destination prefix mask.
IPv4 or IPv6 Destination Mask
Key
Number of bits in the destination
prefix.
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Prefix Port Predefined Record
The Flexible NetFlow "prefix port" predefined record creates flows based on source and destination
prefixes and ports in the traffic flow data. The Flexible NetFlow "prefix port" predefined record uses the
same key and nonkey fields as the original NetFlow "prefix port" aggregation cache.
This predefined record is particularly useful for capturing data with which you can examine the sources and
destinations of network traffic passing through a NetFlow-enabled device.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the destination Flexible NetFlow "prefix port"
predefined record.
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Configuring Cisco IOS Flexible NetFlow with Predefined Records
Information About Configuring Flexible NetFlow with Predefined Records
Table 18
Key and Nonkey Fields Used by the Flexible NetFlow Prefix Port Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Protocol
Key
Value in the IP protocol field.
IPv4 Source Prefix
Key
Source IP address ANDed with
the source prefix mask, or the
prefix to which the source IP
address of the aggregated flows
belongs.
IPv4 Source Mask
Key
Number of bits in the source
prefix.
IPv4 Destination Prefix
Key
Destination IP address ANDed
with the destination prefix mask.
IPv4 Destination Mask
Key
Number of bits in the destination
prefix.
Transport Source Port
Key
Value in the transport layer
source port field.
Transport Destination Port
Key
Value in the transport layer
destination port field.
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
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Prefix ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Prefix ToS Predefined Record
The Flexible NetFlow "prefix ToS" predefined record creates flows based on source and destination
prefixes and ToS traffic flow data. The Flexible NetFlow "prefix ToS" predefined record uses the same key
and nonkey fields as the original NetFlow "destination prefix ToS" aggregation cache.
This predefined record is particularly useful for capturing data with which you can examine the sources and
destinations of network traffic passing through a NetFlow-enabled device.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "prefix ToS" predefined
record.
Table 19
Key and Nonkey Fields Used by the Flexible NetFlow Prefix ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
IP Destination autonomous
system
Key
Autonomous system of the
destination IP address (peer or
origin).
IPv4 Source Prefix
Key
Source IP address ANDed with
the source prefix mask, or the
prefix to which the source IP
address of the aggregated flows
belongs.
IPv4 Source Mask
Key
Number of bits in the source
prefix.
IPv4 Destination Prefix
Key
Destination IP address ANDed
with the destination prefix mask.
IPv4 Destination Mask
Key
Number of bits in the destination
prefix.
Interface Input
Key
Interface on which the traffic is
received.
Interface Output
Key
Interface on which the traffic is
transmitted.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
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Protocol Port Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
Protocol Port Predefined Record
The Flexible NetFlow "protocol port" predefined record creates flows based on protocols and ports in the
traffic flow data. The Flexible NetFlow "protocol port" predefined record uses the same key and nonkey
fields as the original NetFlow "protocol port" aggregation cache.
Note
This predefined record can be used to analyze IPv4 and IPv6 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "protocol port" predefined
record.
Table 20
Key and Nonkey Fields Used by the Flexible NetFlow Protocol Port Predefined Record
Field
Key or Nonkey Field
Definition
IP Protocol
Key
Value in the IP protocol field.
Transport Source Port
Key
Value in the transport layer
source port field.
Transport Destination Port
Key
Value in the transport layer
destination port field.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
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System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Protocol Port ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Time Stamp System Uptime Last
Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Protocol Port ToS Predefined Record
The Flexible NetFlow "protocol port ToS" predefined record creates flows based on the protocol, port, and
ToS value in the traffic data. The Flexible NetFlow "protocol port ToS" predefined record uses the same
key and nonkey fields as the original NetFlow "protocol port ToS" aggregation cache.
This predefined record is particularly useful for capturing data with which you can examine network usage
by type of traffic.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "protocol port ToS"
predefined record.
Table 21
Key and Nonkey Fields Used by the Flexible NetFlow Protocol Port ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Protocol
Key
Value in the IP protocol field.
Transport Source Port
Key
Value in the transport layer
source port field.
Transport Destination Port
Key
Value in the transport layer
destination port field.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
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Source Prefix Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Time Stamp System Uptime Last
Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Source Prefix Predefined Record
The Flexible NetFlow "source prefix" predefined record creates flows based on source prefixes in the
network traffic. The Flexible NetFlow "source prefix" predefined record uses the same key and nonkey
fields as the original NetFlow "source prefix" aggregation cache.
Note
This predefined record can be used to analyze IPv4 and IPv6 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "source prefix" predefined
record.
Table 22
Key and Nonkey Fields Used by the Flexible NetFlow Source Prefix Predefined Record
Field
Key or Nonkey Field
Definition
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
IPv4 or IPv6 Source Prefix
Key
Source IP address ANDed with
the source prefix mask, or the
prefix to which the source IP
address of the aggregated flows
belongs.
IPv4 or IPv6 Source Mask
Key
Number of bits in the source
prefix.
Interface Input
Key
Interface on which the traffic is
received.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
Time Stamp System Uptime First Nonkey
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System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Source Prefix ToS Predefined Record
Information About Configuring Flexible NetFlow with Predefined Records
Field
Key or Nonkey Field
Definition
Time Stamp System Uptime Last
Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Source Prefix ToS Predefined Record
The Flexible NetFlow "source prefix ToS" predefined record creates flows based on source prefixes and
ToS values in the network traffic. The Flexible NetFlow "source prefix ToS" predefined record uses the
same key and nonkey fields as the original NetFlow "source prefix ToS" aggregation cache.
This predefined record is particularly useful for capturing data with which you can examine the sources of
network traffic passing through a NetFlow-enabled device.
Note
This predefined record can be used to analyze only IPv4 traffic.
The table below lists the key and nonkey fields used in the Flexible NetFlow "source prefix ToS"
predefined record.
Table 23
Key and Nonkey Fields Used by the Flexible NetFlow Source Prefix ToS Predefined Record
Field
Key or Nonkey Field
Definition
IP ToS
Key
Value in the ToS field.
IP Source autonomous system
Key
Autonomous system of the source
IP address (peer or origin).
IPv4 Source Prefix
Key
Source IP address ANDed with
the source prefix mask, or the
prefix to which the source IP
address of the aggregated flows
belongs.
IPv4 Source Mask
Key
Number of bits in the source
prefix.
Interface Input
Key
Interface on which the traffic is
received.
Flow Direction
Key
Direction in which the flow is
being monitored.
Counter Bytes
Nonkey
Number of bytes seen in the flow.
Counter Packets
Nonkey
Number of packets seen in the
flow.
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Configuring a Flow Monitor for IPv4 Traffic Using a Predefined Record
How to Configure a Predefined Record for the Flow Monitor
Field
Key or Nonkey Field
Definition
Time Stamp System Uptime First Nonkey
System uptime (time, in
milliseconds, since this device
was first booted) when the first
packet was switched.
Time Stamp System Uptime Last
System uptime (time, in
milliseconds, since this device
was first booted) when the last
packet was switched.
Nonkey
How to Configure a Predefined Record for the Flow Monitor
Note
Only the keywords and arguments required for the Flexible NetFlow commands used in these tasks are
explained in these tasks. For information on the other keywords and arguments available for these Flexible
NetFlow commands, refer to the Cisco IOS Flexible NetFlow Command Reference.
•
•
•
•
Configuring a Flow Monitor for IPv4 Traffic Using a Predefined Record, page 60
Configuring a Flow Monitor for IPv6 Traffic Using a Predefined Record, page 62
Applying an IPv4 Flow Monitor to an Interface, page 64
Applying an IPv6 Flow Monitor to an Interface, page 65
Configuring a Flow Monitor for IPv4 Traffic Using a Predefined Record
To configure a flow monitor for IPv4 traffic using a 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 on which you have applied it before you can
modify the record format of the flow monitor.
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Configuring Cisco IOS Flexible NetFlow with Predefined Records
How to Configure a Predefined Record for the Flow Monitor
SUMMARY STEPS
1. enable
2. configure terminal
3. flow monitor monitor-name
4. description description
5. record {netflow-original | netflow ipv4 record [peer]}
6. end
7. show flow record record-name
8. show running-config flow record record-name
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 flow monitor monitor-name
Example:
Creates a flow monitor and enters Flexible NetFlow
flow monitor configuration mode.
•
This command also allows you to modify an
existing flow monitor.
Router(config)# flow monitor FLOW-MONITOR-1
Step 4 description description
(Optional) Creates a description for the flow monitor.
Example:
Router(config-flow-monitor)# description Used for
monitoring IPv4 traffic
Step 5 record {netflow-original | netflow ipv4 record [peer]}
Specifies the record for the flow monitor.
Example:
Router(config-flow-monitor)# record netflow ipv4
original-input
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Configuring a Flow Monitor for IPv6 Traffic Using a Predefined Record
How to Configure a Predefined Record for the Flow Monitor
Command or Action
Step 6 end
Purpose
Exits Flexible NetFlowflow monitor configuration
mode and returns to privileged EXEC mode.
Example:
Router(config-flow-monitor)# end
Step 7 show flow record record-name
(Optional) Displays the current status of the specified
flow record.
Example:
Router# show flow record FLOW_RECORD-1
Step 8 show running-config flow record record-name
(Optional) Displays the configuration of the specified
flow record.
Example:
Router# show running-config flow record FLOW_RECORD-1
Configuring a Flow Monitor for IPv6 Traffic Using a Predefined Record
To configure a flow monitor for IPv6 traffic using a 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 on 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 ipv6 record [peer]
6. end
7. show flow record record-name
8. show running-config flow record record-name
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Configuring Cisco IOS Flexible NetFlow with Predefined Records
How to Configure a Predefined Record for the Flow Monitor
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 flow monitor monitor-name
Example:
Creates a flow monitor and enters Flexible NetFlow
flow monitor configuration mode.
•
This command also allows you to modify an
existing flow monitor.
Router(config)# flow monitor FLOW-MONITOR-2
Step 4 description description
(Optional) Creates a description for the flow monitor.
Example:
Router(config-flow-monitor)# description Used for
monitoring IPv6 traffic
Step 5 record netflow ipv6 record [peer]
Specifies the record for the flow monitor.
Example:
Router(config-flow-monitor)# record netflow ipv6
original-input
Step 6 end
Exits Flexible NetFlow flow monitor configuration
mode and returns to privileged EXEC mode.
Example:
Router(config-flow-monitor)# end
Step 7 show flow record record-name
(Optional) Displays the current status of the specified
flow record.
Example:
Router# show flow record FLOW_RECORD-1
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Applying an IPv4 Flow Monitor to an Interface
How to Configure a Predefined Record for the Flow Monitor
Command or Action
Purpose
Step 8 show running-config flow record record-name
(Optional) Displays the configuration of the specified
flow record.
Example:
Router# show running-config flow record FLOW_RECORD-1
Applying an IPv4 Flow Monitor to an Interface
Before it can be activated, an IPv4 flow monitor must be applied to at least one interface. To activate an
IPv4 flow monitor by applying the flow monitor to an interface, perform the following required task.
Note
When you specify the "NetFlow original" or the "NetFlow IPv4 original input" predefined record for the
flow monitor to emulate original NetFlow, the flow monitor can be used for analyzing only input (ingress)
traffic.
When you specify the "NetFlow IPv4 original output" predefined record for the flow monitor to emulate
the Egress NetFlow Accounting feature, the flow monitor can be used for analyzing only output (egress)
traffic.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ip flow monitor monitor-name {input | output}
5. end
6. show flow monitor monitor-name
7. show flow monitor [[name] monitor-name [cache [format {csv | record | table}]][statistics]]
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Example:
Router> enable
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Enter your password if prompted.
Applying an IPv6 Flow Monitor to an Interface
How to Configure a Predefined Record for the Flow Monitor
Command or Action
Step 2 configure terminal
Purpose
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 interface type number
Specifies an interface and enters interface configuration mode.
Example:
Router(config)# interface ethernet 0/0
Step 4 ip flow monitor monitor-name {input | output}
Activates the flow monitor that you created previously by
assigning it to the interface to analyze traffic.
•
Example:
Router(config-if)# ip flow monitor FLOWMONITOR-1 input
Step 5 end
You can configure input and output traffic analysis
concurrently by configuring the ip flow monitor monitorname input and ip flow monitor monitor-name output
commands on the same interface. You can use different
flow monitors for input and output traffic analysis.
Exits interface configuration mode and returns to privileged
EXEC mode.
Example:
Router(config-if)# end
Step 6 show flow monitor monitor-name
(Optional) Displays the current status of the specified flow
monitor.
Example:
Router# show flow monitor FLOW_MONITOR-1
Step 7 show flow monitor [[name] monitor-name [cache
[format {csv | record | table}]][statistics]]
(Optional) Displays the status and statistics for a Flexible
NetFlow flow monitor.
Example:
Router# show flow monitor FLOW-MONITOR-1
Applying an IPv6 Flow Monitor to an Interface
Before it can be activated, an IPv6 flow monitor must be applied to at least one interface. To activate an
IPv4 flow monitor by applying the flow monitor to an interface, perform the following required task.
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How to Configure a Predefined Record for the Flow Monitor
Note
When you specify 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 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. interface type number
4. ipv6 flow monitor monitor-name {input | output}
5. end
6. show flow monitor monitor-name
7. show running-config flow monitor monitor-name
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Router# configure terminal
Step 3 interface type number
Specifies an interface and enters interface configuration mode.
Example:
Router(config)# interface ethernet 0/0
Step 4 ipv6 flow monitor monitor-name {input | output}
Example:
Router(config-if)# ipv6 flow monitor FLOWMONITOR-2 input
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Activates the flow monitor that you created previously by
assigning it to the interface to analyze traffic.
•
You can configure input and output traffic analysis
concurrently by configuring the ipv6 flow monitor monitorname input and ipv6 flow monitor monitor-name output
commands on the same interface. You can use different flow
monitors for input and output traffic analysis.
Example: Configuring a Flexible NetFlow Predefined Record for IPv4 Traffic
Configuration Examples for Flexible NetFlow with Predefined Records
Command or Action
Step 5 end
Purpose
Exits interface configuration mode and returns to privileged
EXEC mode.
Example:
Router(config-if)# end
Step 6 show flow monitor monitor-name
(Optional) Displays the current status of the specified flow
monitor.
Example:
Router# show flow monitor FLOW_MONITOR-1
Step 7 show running-config flow monitor monitor-name
(Optional) Displays the configuration of the specified flow
monitor.
Example:
Router# show flow monitor FLOW_MONITOR-1
Configuration Examples for Flexible NetFlow with Predefined
Records
•
•
Example: Configuring a Flexible NetFlow Predefined Record for IPv4 Traffic, page 67
Example: Configuring a Flexible NetFlow Predefined Record for IPv6 Traffic, page 67
Example: Configuring a Flexible NetFlow Predefined Record for IPv4 Traffic
The following example shows how to configure a flow monitor using the Flexible NetFlow "BGP ToS
next-hop" predefined record to monitor IPv4 traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 bgp-nexthop-tos
exit
!
ip cef
!
interface Ethernet 0/0
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 input
!
Example: Configuring a Flexible NetFlow Predefined Record for IPv6 Traffic
The following example shows how to configure a flow monitor using the Flexible NetFlow "source prefix"
predefined record to monitor IPv6 traffic.
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Configuring Cisco IOS Flexible NetFlow with Predefined Records
Where to Go Next
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-2
record netflow ipv6 source-prefix
exit
ip cef
ipv6 cef
!
interface Ethernet 0/0
ipv6 address 2001:DB8:2:ABCD::2/48
ipv6 flow monitor FLOW-MONITOR-2 input
!
Where to Go Next
For information on advanced Flexible NetFlow configurations for specific purposes such as quality of
service (QoS) and bandwidth monitoring, application and user flow monitoring and profiling, and security
analysis, refer to the "Customizing Cisco IOS Flexible NetFlow Flow Records and Flow Monitors"
module.
If you want to configure flow sampling to reduce the CPU overhead of analyzing traffic, refer to the "Using
Cisco IOS Flexible NetFlow Flow Sampling to Reduce the CPU Overhead of Analyzing Traffic" module.
If you want to configure data export for Flexible NetFlow, refer to the "Configuring Data Export for Cisco
IOS Flexible NetFlow with Flow Exporters" module.
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Overview of Flexible NetFlow
"Cisco IOS Flexible NetFlow Overview"
Emulating original NetFlow with Flexible NetFlow
"Getting Started with Configuring Cisco IOS
Flexible NetFlow"
Configuring flow exporters to export Flexible
NetFlow data
"Configuring Data Export for Cisco IOS Flexible
NetFlow with Flow Exporters"
Customizing Flexible NetFlow
"Customizing Cisco IOS Flexible NetFlow Flow
Records and Flow Monitors"
Configuring flow sampling to reduce the overhead
of monitoring traffic with Flexible NetFlow
"Using Cisco IOS Flexible NetFlow Flow Sampling
to Reduce the CPU Overhead of Analyzing Traffic"
Using Flexible NetFlow Top N Talkers to analyze
network traffic
"Using Cisco IOS Flexible NetFlow Top N Talkers
to Analyze Network Traffic"
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Configuring Cisco IOS Flexible NetFlow with Predefined Records
Feature Information for Flexible NetFlow
Related Topic
Document Title
Configuring IPv4 multicast statistics support for
Flexible NetFlow
"Configuring IPv4 Multicast Statistics Support for
Cisco IOS Flexible NetFlow"
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Standards
Standard
Title
None
--
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:
http://www.cisco.com/go/mibs
RFCs
RFC
Title
RFC 3954
Cisco Systems NetFlow Services Export Version 9
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.
http://www.cisco.com/cisco/web/support/
index.html
Feature Information for Flexible NetFlow
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.
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Feature Information for Flexible NetFlow
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.
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Feature Information for Flexible NetFlow
Table 24
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow
12.2(33)SRC
Flexible NetFlow is introduced.
12.2(50)SY
Support for this feature was
added for Cisco 7200 series
routers in Cisco IOS Release
12.2(33)SRC.
12.4(9)T
15.0(1)SY
15.0(1)SY1
The following commands were
introduced or modified:
cache(Flexible NetFlow), clear
flow exporter, clear flow
monitor, clear sampler, collect
counter, collect flow, collect
interface, collect ipv4, collect
ipv4 destination, collect ipv4
fragmentation, collect ipv4
section, collect ipv4 source,
collect ipv4 total-length, collect
ipv4 ttl, collect routing, collect
timestamp sys-uptime, collect
transport, collect transport
icmp ipv4, collect transport tcp,
collect transport udp, debug
flow exporter, debug flow
monitor, debug flow record,
debug sampler, description
(Flexible NetFlow), destination,
dscp (Flexible NetFlow),
exporter, flow exporter, flow
monitor, flow platform, flow
record, ip flow monitor, match
flow, match interface (Flexible
NetFlow), match ipv4, match
ipv4 destination, match ipv4
fragmentation, match ipv4
section, match ipv4 source,
match ipv4 total-length, match
ipv4 ttl, match routing, match
transport, match transport
icmp ipv4, match transport tcp,
match transport udp, mode
(Flexible NetFlow), option
(Flexible NetFlow), record,
sampler, show flow exporter,
show flow interface, show flow
monitor, show flow record,
show sampler, source (Flexible
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Feature Name
Releases
Feature Information
NetFlow), statistics packet,
template data timeout,
transport (Flexible NetFlow).
Flexible NetFlow--IPv6 Unicast
Flows
12.2(33)SRE
12.2(50)SY
12.4(20)T
15.0(1)SY
15.0(1)SY1
Enables Flexible NetFlow to
monitor IPv6 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
routing, debug flow record,
match routing, record, show
flow monitor, show flow record,
collect ipv6, collect ipv6
destination, collect ipv6
extension map, collect ipv6
fragmentation, collect ipv6 hoplimit, collect ipv6 length, collect
ipv6 section, collect ipv6 source,
collect transport icmp ipv6,
ipv6 flow monitor, match ipv6,
match ipv6 destination, match
ipv6 extension map, match ipv6
fragmentation, match ipv6 hoplimit, match ipv6 length, match
ipv6 section, match ipv6 source,
match transport icmp ipv6.
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.
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Configuring Data Export for Flexible NetFlow
with Flow Exporters
This document contains information about and instructions for configuring flow exporters to export
Flexible NetFlow data to remote systems such as a UNIX server running NetFlow collector.
NetFlow is a Cisco IOS technology that provides statistics on packets flowing through the router. NetFlow
is the standard for acquiring IP operational data from IP networks. NetFlow provides data to support
network and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
•
•
•
•
•
•
•
•
•
Finding Feature Information, page 73
Prerequisites for Data Export for Flexible NetFlow with Flow Exporters, page 73
Restrictions for Data Export for Flexible NetFlow with Flow Exporters, page 74
Information About Data Export for Flexible NetFlow with Flow Exporters, page 74
How to Configure Data Export for Flexible NetFlow with Flow Exporters, page 75
Configuration Examples for Flexible NetFlow Data Export with Flow Exporters, page 81
Where to Go Next, page 83
Additional References, page 83
Feature Information for Flexible NetFlow, page 85
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.
Prerequisites for Data Export for Flexible NetFlow with Flow
Exporters
•
You are familiar with the information in the "Cisco IOS Flexible NetFlow Overview" module.
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Flow Exporters
Restrictions for Data Export for Flexible NetFlow with Flow Exporters
•
The networking device must be running a Cisco IOS or Cisco IOS XE release that supports Flexible
NetFlow.
IPv4 Traffic
•
•
The networking device must be configured for IPv4 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding.
IPv6 Traffic
•
•
The networking device must be configured for IPv6 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding.
Restrictions for Data Export for Flexible NetFlow with Flow
Exporters
•
The NetFlow Version 5 export protocol that was first shipped in Cisco IOS Release 12.4(22)T is
supported for flow monitors that use only the following Flexible NetFlow predefined records: netfloworiginal, original input, and original output.
Information About Data Export for Flexible NetFlow with Flow
Exporters
•
•
Flow Exporters, page 74
Benefits of Flexible NetFlow Flow Exporters, page 74
Flow Exporters
Flow exporters are created as separate components in a router’s configuration. Exporters are assigned to
flow monitors to export the data from the flow monitor cache to a remote system such as a NetFlow
collector. Flow monitors can support more than one exporter. Each exporter can be customized to meet the
requirements of the flow monitor or monitors in which it is used and the NetFlow collector systems to
which it is exporting data.
Benefits of Flexible NetFlow Flow Exporters
Flexible NetFlow allows you to configure many different flow exporters, depending on your requirements.
Some of the benefits of Flexible NetFlow flow exporters are as follows:
•
Using flow exporters, you can create an exporter for every type of traffic that you want to analyze so
that you can send each type of traffic to a different NetFlow collector. Original NetFlow sends the data
in a cache for all of the analyzed traffic to a maximum of two export destinations.
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Restrictions
How to Configure Data Export for Flexible NetFlow with Flow Exporters
•
•
•
•
Flow exporters support up to ten exporters per flow monitor. Original NetFlow is limited to only two
export destinations per cache.
Flow exporters can use both TCP and UDP for export.
Depending on your release, flow exporters can use class of service (CoS) in the packets that are sent to
export destinations to help ensure that the packets are given the correct priority throughout the
network. Original NetFlow exporters do not use CoS in the packets that are sent to export destinations.
Depending on your release, flow exporter traffic can be encrypted.
How to Configure Data Export for Flexible NetFlow with Flow
Exporters
The tasks in this section explain how to export the data that is collected by Flexible NetFlow to a remote
system for further analysis and storage.
Flow exporters are used to send the data that you collect with Flexible NetFlow to a remote system such as
a NetFlow collector. Flow exporters use UDP as the transport protocol.
•
•
•
Restrictions, page 75
Configuring the Flow Exporter, page 75
Configuring and Enabling Flexible NetFlow with Data Export, page 79
Restrictions
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. Flow exporters are added
to flow monitors to enable data export from the flow monitor cache.
Note
Only the keywords and arguments required for the Flexible NetFlow commands used in these tasks are
explained in these tasks. For information about the other keywords and arguments available for these
Flexible NetFlow commands, refer to the Cisco IOS Flexible NetFlow Command Reference .
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.
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How to Configure Data Export for Flexible NetFlow with Flow Exporters
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
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 flow exporter exporter-name
Example:
Device(config)# flow exporter EXPORTER-1
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Creates the flow exporter and enters Flexible NetFlow flow
exporter configuration mode.
•
This command also allows you to modify an existing flow
exporter.
Configuring Data Export for Flexible NetFlow with Flow Exporters
How to Configure Data Export for Flexible NetFlow with Flow Exporters
Command or Action
Step 4 description description
Purpose
(Optional) Configures a description to the exporter that will appear
in the configuration and the display of the show flow exporter
command.
Example:
Device(config-flow-exporter)# description
Exports to the datacenter
Step 5 destination {ip-address | hostname} [vrf vrf-name] Specifies the IP address or hostname of the destination system for
the exporter.
Example:
Note You can export to a destination using either an IPv4 or IPv6
address.
Device(config-flow-exporter)# destination
172.16.10.2
Step 6 export-protocol {netflow-v5 | netflow-v9 | ipfix}
Example:
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.
Device(config-flow-exporter)# exportprotocol netflow-v9
Step 7 dscp dscp
Example:
(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.
Device(config-flow-exporter)# dscp 63
Step 8 source interface-type interface-number
(Optional) Specifies the local interface from which the exporter
will use the IP address as the source IP address for exported
datagrams.
Example:
Device(config-flow-exporter)# source
ethernet 0/0
Step 9 option {exporter-stats | interface-table | sampler- (Optional) Configures options data parameters for the exporter.
table| vrf-table} [timeout seconds]
• You can configure all three options concurrently.
• The range for the seconds argument is 1 to 86,400. Default:
600.
Example:
Device(config-flow-exporter)# option
exporter-stats timeout 120
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How to Configure Data Export for Flexible NetFlow with Flow Exporters
Command or Action
Step 10 output-features
Purpose
(Optional) Enables sending export packets using quality of service
(QoS) and encryption.
Example:
Device(config-flow-exporter)# outputfeatures
Step 11 template data timeout seconds
(Optional) Configure resending of templates based on a timeout.
•
Example:
The range for the seconds argument is 1 to 86400 (86400
seconds = 24 hours).
Device(config-flow-exporter)# template
data timeout 120
Step 12 transport udp udp-port
Example:
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.
Device(config-flow-exporter)# transport
udp 650
Step 13 ttl seconds
Example:
(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.
Device(config-flow-exporter)# ttl 15
Step 14 end
Exits flow exporter configuration mode and returns to privileged
EXEC mode.
Example:
Device(config-flow-exporter)# end
Step 15 show flow exporter exporter-name
(Optional) Displays the current status of the specified flow
exporter.
Example:
Device# show flow exporter FLOW_EXPORTER-1
Step 16 show running-config flow exporter exportername
Example:
Device# show running-config flow exporter
FLOW_EXPORTER-1
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(Optional) Displays the configuration of the specified flow
exporter.
Configuring and Enabling Flexible NetFlow with Data Export
How to Configure Data Export for Flexible NetFlow with Flow Exporters
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
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
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Configuring Data Export for Flexible NetFlow with Flow Exporters
How to Configure Data Export for Flexible NetFlow with Flow Exporters
Command or Action
Step 2 configure terminal
Purpose
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 flow monitor monitor-name
Example:
Creates a flow monitor and enters Flexible NetFlow flow
monitor configuration mode.
•
This command also allows you to modify an
existing flow monitor.
Device(config)# flow monitor FLOW-MONITOR-1
Step 4 record {record-name | netflow-original | netflow {ipv4 |
ipv6 record [peer] }]
Specifies the record for the flow monitor.
Example:
Device(config-flow-monitor)# record netflow ipv4
original-input
Step 5 exporter exporter-name
Specifies the name of an exporter that you created
previously.
Example:
Device(config-flow-monitor)# exporter EXPORTER-1
Step 6 exit
Exits Flexible NetFlow flow monitor configuration mode
and returns to global configuration mode.
Example:
Device(config-flow-monitor)# exit
Step 7 interface type number
Specifies an interface and enters interface configuration
mode.
Example:
Device(config)# interface ethernet 0/0
Step 8 {ip | ipv6} flow monitor monitor-name {input | output}
Example:
Device(config-if)# ip flow monitor FLOW-MONITOR-1
input
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Activates the flow monitor that you created previously
by assigning it to the interface to analyze traffic.
Example: Configuring Multiple Export Destinations
Configuration Examples for Flexible NetFlow Data Export with Flow Exporters
Command or Action
Purpose
Step 9 end
Exits interface configuration mode and returns to
privileged EXEC mode.
Example:
Device(config-if)# end
Step 10 show flow monitor [[name] monitor-name [cache [format
{csv | record | table}]][statistics]]
(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:
Device# show flow monitor FLOW-MONITOR-2 cache
Configuration Examples for Flexible NetFlow Data Export
with Flow Exporters
•
•
•
Example: Configuring Multiple Export Destinations, page 81
Example: Configuring Sending Export Packets Using QoS, page 82
Example: Configuring Version 5 Export, page 83
Example: Configuring Multiple Export Destinations
The following example shows how to configure multiple export destinations for Flexible NetFlow for IPv4
and 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
!
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Example: Configuring Sending Export Packets Using QoS
Configuration Examples for Flexible NetFlow Data Export with Flow Exporters
interface Ethernet 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:
Device# 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
Status:
allocated
Size:
4096 entries / 311316 bytes
Inactive Timeout: 15 secs
Active Timeout:
1800 secs
Update Timeout:
1800 secs
Example: Configuring Sending Export Packets Using QoS
The following example shows how to enable QoS on Flexible Netflow export packets.
Note
The Flexible NetFlow export packets are transmitted using QoS on Ethernet interface 0/1 (the interface on
which the destination is reachable) to the destination host (IP address 10.0.1.2).
This sample starts in global configuration mode:
!
flow record FLOW-RECORD-1
match ipv4 source address
collect counter packets
!
flow exporter FLOW-EXPORTER-1
destination 10.0.1.2
output-features
dscp 18
!
flow monitor FLOW-MONITOR-1
record FLOW-RECORD-1
exporter FLOW-EXPORTER-1
cache entries 1024
!
ip cef
!
class-map match-any COS3
!
policy-map PH_LABS_FRL_64k_16k_16k_8k_8k
class COS3
bandwidth percent 2
random-detect dscp-based
random-detect exponential-weighting-constant 1
random-detect dscp 18 200 300 10
!
interface Ethernet 0/0
ip address 10.0.0.1 255.255.255.0
ip flow monitor FLOW-MONITOR-1 input
!
interface Ethernet 0/1
ip address 10.0.1.1 255.255.255.0
service-policy output PH_LABS_FRL_64k_16k_16k_8k_8k
!
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Example: Configuring Version 5 Export
Where to Go Next
The following display output shows that the flow monitor is exporting data using output feature support
that enables the exported data to use QoS:
Device# show flow monitor FLOW-MONITOR-1
Flow Exporter FLOW-EXPORTER-1:
Description:
User defined
Tranport Configuration:
Destination IP address: 10.0.1.2
Source IP address:
10.0.0.1
Transport Protocol:
UDP
Destination Port:
9995
Source Port:
56750
DSCP:
0x12
TTL:
255
Output Features:
Used
Example: Configuring Version 5 Export
The following example shows how to configure version 5 export for Flexible NetFlow.
This sample starts in global configuration mode:
!
flow exporter EXPORTER-1
destination 172.16.10.2
export-protocol netflow-v5
transport udp 90
exit
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 original-input
exporter EXPORTER-1
!
ip cef
!
interface Ethernet 0/0
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 input
!
Where to Go Next
For information on advanced Flexible NetFlow configurations for specific purposes such as QoS and
bandwidth monitoring, application and user flow monitoring and profiling, and security analysis, refer to
the "Customizing Cisco IOS Flexible NetFlow Flow Records and Flow Monitors" module.
If you want to configure flow sampling to reduce the CPU overhead of analyzing traffic, refer to the "Using
Cisco IOS Flexible NetFlow Flow Sampling to Reduce the CPU Overhead of Analyzing Traffic" module.
If you want to configure any of the predefined records for Flexible NetFlow, refer to the "Configuring
Cisco IOS Flexible NetFlow with Predefined Records" module.
Additional References
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Configuring Data Export for Flexible NetFlow with Flow Exporters
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Overview of Flexible NetFlow
"Cisco IOS Flexible NetFlow Overview"
Emulating original NetFlow with Flexible NetFlow
"Getting Started with Configuring Cisco IOS
Flexible NetFlow"
Customizing Flexible NetFlow
"Customizing Cisco IOS Flexible NetFlow Flow
Records and Flow Monitors"
Configuring flow sampling to reduce the overhead
of monitoring traffic with Flexible NetFlow
"Using Cisco IOS Flexible NetFlow Flow Sampling
to Reduce the CPU Overhead of Analyzing Traffic"
Configuring Flexible NetFlow using predefined
records
"Configuring Cisco IOS Flexible NetFlow with
Predefined Records"
Using Flexible NetFlow Top N Talkers to analyze
network traffic
"Using Cisco IOS Flexible NetFlow Top N Talkers
to Analyze Network Traffic"
Configuring IPv4 multicast statistics support for
Flexible NetFlow
"Configuring IPv4 Multicast Statistics Support for
Cisco IOS Flexible NetFlow"
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Standards
Standard
Title
None
--
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:
http://www.cisco.com/go/mibs
RFCs
RFC
Title
RFC 3954
Cisco Systems NetFlow Services Export Version 9
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Configuring Data Export for Flexible NetFlow with Flow Exporters
Feature Information for Flexible NetFlow
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.
http://www.cisco.com/cisco/web/support/
index.html
Feature Information for Flexible NetFlow
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.
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Feature Information for Flexible NetFlow
Table 25
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow
12.2(33)SRC
Flexible NetFlow is introduced.
12.2(50)SY
Support for this feature was
added for Cisco 7200 series
routers in Cisco IOS Release
12.2(33)SRC.
12.4(9)T
15.0(1)SY
15.0(1)SY1
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The following commands were
introduced or modified: cache
(Flexible NetFlow), clear flow
exporter, clear flow monitor,
clear sampler, collect counter,
collect flow, collect interface,
collect ipv4, collect ipv4
destination, collect ipv4
fragmentation, collect ipv4
section, collect ipv4 source,
collect ipv4 total-length, collect
ipv4 ttl, collect routing, collect
timestamp sys-uptime, collect
transport, collect transport
icmp ipv4, collect transport tcp,
collect transport udp, debug
flow exporter, debug flow
monitor, debug flow record,
debug sampler, description
(Flexible NetFlow), destination,
dscp (Flexible NetFlow),
exporter, flow exporter, flow
monitor, flow platform, flow
record, ip flow monitor, match
flow, match interface (Flexible
NetFlow), match ipv4, match
ipv4 destination, match ipv4
fragmentation, match ipv4
section, match ipv4 source,
match ipv4 total-length, match
ipv4 ttl, match routing, match
transport, match transport
icmp ipv4, match transport tcp,
match transport udp, mode
(Flexible NetFlow), option
(Flexible NetFlow), record,
sampler, show flow exporter,
show flow interface, show flow
monitor, show flow record,
show sampler, source (Flexible
NetFlow), statistics packet,
Configuring Data Export for Flexible NetFlow with Flow Exporters
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
template data timeout,
transport (Flexible NetFlow).
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.
Flexible NetFlow--NetFlow v9
Export Format
12.2(33)SRE
12.2(50)SY
12.4(9)T
15.0(1)SY
15.0(1)SY1
Enables sending export packets
using the Version 9 export
format.
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.
No commands were introduced or
modified by this feature.
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Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow--IPv6 Unicast
Flows
12.2(33)SRE
Enables Flexible NetFlow to
monitor IPv6 traffic.
12.2(50)SY
12.4(20)T
15.0(1)SY
15.0(1)SY1
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
routing, debug flow record,
match routing, record, show
flow monitor, show flow record,
collect ipv6, collect ipv6
destination, collect ipv6
extension map, collect ipv6
fragmentation, collect ipv6 hoplimit, collect ipv6 length, collect
ipv6 section, collect ipv6 source,
collect transport icmp ipv6,
ipv6 flow monitor, match ipv6,
match ipv6 destination, match
ipv6 extension map, match ipv6
fragmentation, match ipv6 hoplimit, match ipv6 length, match
ipv6 section, match ipv6 source,
match transport icmp ipv6.
Flexible NetFlow--Output
Features on Data Export
12.4(20)T
Enables sending export packets
using QoS and encryption.
The following command was
introduced: output-features.
Flexible NetFlow--NetFlow V5
Export Protocol
12.2(33)SRE
12.2(50)SY
12.4(22)T
15.0(1)SY
15.0(1)SY1
Enables sending export packets
using the Version 5 export
protocol.
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 command was
introduced: export-protocol.
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Configuring Data Export for Flexible NetFlow with Flow Exporters
Feature Name
Releases
Feature Information
Flexible NetFlow: Export to an
IPv6 Address
15.2(2)T
This feature enables Flexible
NetFlow to export data to a
destination using an IPv6 address.
The following commands were
introduced or modified:
destination
Flexible NetFlow: IPFIX Export
Format
15.2(4)M
Enables sending export packets
using the IPFIX export protocol.
The export of extracted fields
from NBAR is only supported
over IPFIX.
Support for this feature was
added for Cisco ASR 1000 Series
Aggregation Services routers in
Cisco IOS XE Release 3.7S.
The following command was
introduced: export-protocol.
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.
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Example: Configuring Version 5 Export
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Customizing Flexible NetFlow Flow Records
and Flow Monitors
This document contains information about and instructions for customizing Cisco IOS Flexible NetFlow
flow records and flow monitors. If the tasks and configuration examples in the "Getting Started with
Configuring Cisco IOS Flexible NetFlow" module and the "Configuring Cisco IOS Flexible NetFlow with
Predefined Records" module were not suitable for your traffic analysis requirements, you can use the
information and instructions in this document to customize Flexible NetFlow to meet your traffic analysis
requirements.
NetFlow is a Cisco IOS technology that provides statistics on packets flowing through a router. NetFlow
is the standard for acquiring IP operational data from IP networks. NetFlow provides data to support
network and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow facilitates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
•
•
•
•
•
•
•
•
Finding Feature Information, page 91
Prerequisites for Customizing Flexible NetFlow Flow Records and Flow Monitors, page 92
Information About Customizing Flexible NetFlow Flow Records and Flow Monitors, page 92
How to Customize Flexible NetFlow Flow Records and Flow Monitors, page 93
Configuration Examples for Customizing Flow Records and Flow Monitors, page 100
Where to Go Next, page 104
Additional References, page 104
Feature Information for Flexible NetFlow, page 105
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.
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Criteria for Identifying Traffic To Be Used in Analysis in Flexible NetFlow
Prerequisites for Customizing Flexible NetFlow Flow Records and Flow Monitors
Prerequisites for Customizing Flexible NetFlow Flow Records
and Flow Monitors
•
•
•
•
You are familiar with the information in the " Cisco IOS Flexible NetFlow Overview " module.
You are familiar with the Flexible NetFlow key fields as they are defined in the following commands
in the Cisco IOS Flexible NetFlow Command Reference :
◦ match flow
◦ match interface
◦ match {ipv4 | ipv6}
◦ match routing
◦ match transport
You are familiar with the Flexible NetFlow nonkey fields as they are defined in the following
commands in the Cisco IOS Flexible NetFlow Command Reference :
◦ collect counter
◦ collect flow
◦ collect interface
◦ collect{ipv4 | ipv6}
◦ collect routing
◦ collect timestamp sys-uptime
◦ collect transport
The networking device must be running a Cisco IOS release that supports Flexible NetFlow.
IPv4 Traffic
•
•
The networking device must be configured for IPv4 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding.
IPv6 Traffic
•
•
The networking device must be configured for IPv6 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding.
Information About Customizing Flexible NetFlow Flow
Records and Flow Monitors
•
Criteria for Identifying Traffic To Be Used in Analysis in Flexible NetFlow, page 92
Criteria for Identifying Traffic To Be Used in Analysis in Flexible NetFlow
If the predefined Flexible NetFlow records are not suitable for your traffic requirements, you can create a
user-defined (custom) record using the Flexible NetFlow collect and match commands. Before you can
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How to Customize Flexible NetFlow Flow Records and Flow Monitors
create a customized record, you must decide the criteria that you are going to use for the key and nonkey
fields.
If you want to create a customized record for detecting network attacks, you must include the appropriate
key and nonkey fields in the record to ensure that the router creates the flows and captures the data that you
need to analyze the attack and respond to it. For example, SYN flood attacks are a common denial of
service (DoS) attack in which TCP flags are used to flood open TCP requests to a destination host. When a
normal TCP connection starts, a destination host receives a SYN (synchronize/start) packet from a source
host and sends back a SYN ACK (synchronize acknowledge). The destination host must then hear an ACK
(acknowledge) of the SYN ACK before the connection is established. This is referred to as the "TCP threeway handshake." While the destination host waits for the ACK to the SYN ACK, a connection queue of
finite size on the destination host keeps track of connections waiting to be completed. This queue typically
empties quickly because the ACK is expected to arrive a few milliseconds after the SYN ACK. The TCP
SYN attack exploits this design by having an attacking source host generate TCP SYN packets with
random source addresses toward a victim host. The victim destination host sends a SYN ACK back to the
random source address and adds an entry to the connection queue. Because the SYN ACK is destined for
an incorrect or nonexistent host, the last part of the TCP three-way handshake is never completed and the
entry remains in the connection queue until a timer expires, typically for about one minute. Rapid
generation by the source of TCP SYN packets from random IP addresses can fill the connection queue and
cause denial of TCP services (such as e-mail, file transfer, or WWW) to legitimate users.
The information needed for a security monitoring record for this type of DoS attack might include the
following key and nonkey fields:
•
Key fields:
•
◦ Destination IP address or destination IP subnet
◦ TCP flags
◦ Packet count
Nonkey fields
◦
◦
◦
Tip
Destination IP address
Source IP address
Interface input and output
Many users configure a general Flexible NetFlow monitor that triggers a more detailed Flexible NetFlow
view of a DoS attack using these key and nonkey fields.
How to Customize Flexible NetFlow Flow Records and Flow
Monitors
Note
Only the keywords and arguments required for the Flexible NetFlow commands used in these tasks are
explained in these tasks. For information about the other keywords and arguments available for these
Flexible NetFlow commands, refer to the Cisco IOS Flexible NetFlow Command Reference.
•
Configuring a Customized Flow Record, page 94
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Configuring a Customized Flow Record
How to Customize Flexible NetFlow Flow Records and Flow Monitors
•
•
Creating a Customized Flow Monitor, page 96
Applying a Flow Monitor to an Interface, page 98
Configuring 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 explains the steps that
are used to create one of the possible permutations. Modify the steps in these tasks as appropriate to create
a customized flow record for your requirements.
To configure a customized flow record, perform the following task.
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
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Example:
Device# configure terminal
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Enters global configuration mode.
Customizing Flexible NetFlow Flow Records and Flow Monitors
How to Customize Flexible NetFlow Flow Records and Flow Monitors
Command or Action
Step 3 flow record record-name
Example:
Purpose
Creates a flow record and enters Flexible NetFlow flow record
configuration mode.
•
This command also allows you to modify an existing
flow record.
Device(config)# flow record FLOW-RECORD-1
Step 4 description description
(Optional) Creates a description for the flow record.
Example:
Device(config-flow-record)# description Used
for basic traffic analysis
Step 5 match {ipv4 | ipv6}{destination | source} 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 .
Example:
Device(config-flow-record)# match ipv4
destination address
Step 6 Repeat Step 5 as required to configure additional key
fields for the record.
--
Step 7 collect interface {input | output}
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 .
Example:
Device(config-flow-record)# collect interface
input
Step 8 Repeat Step 7 as required to configure additional nonkey -fields for the record.
Step 9 end
Exits Flexible NetFlow flow record configuration mode and
returns to privileged EXEC mode.
Example:
Device(config-flow-record)# end
Step 10 show flow record record-name
(Optional) Displays the current status of the specified flow
record.
Example:
Device# show flow record FLOW_RECORD-1
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How to Customize Flexible NetFlow Flow Records and Flow Monitors
Command or Action
Step 11 show running-config flow record record-name
Purpose
(Optional) Displays the configuration of the specified flow
record.
Example:
Device# show running-config flow record
FLOW_RECORD-1
Creating a Customized Flow Monitor
To create a customized 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.
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
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How to Customize Flexible NetFlow Flow Records and Flow Monitors
DETAILED STEPS
Command or Action
Purpose
Step 1 enable
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 flow monitor monitor-name
Creates a flow monitor and enters Flexible NetFlow
flow monitor configuration mode.
•
Example:
This command also allows you to modify an
existing flow monitor.
Device(config)# flow monitor FLOW-MONITOR-1
Step 4 description description
(Optional) Creates a description for the flow monitor.
Example:
Device(config-flow-monitor)# description Used for
basic ipv4 traffic analysis
Step 5 record {record-name | netflow-original | netflow {ipv4 |
ipv6} record [peer]}
Specifies the record for the flow monitor.
Example:
Device(config-flow-monitor)# record FLOW-RECORD-1
Step 6 cache {entries number | timeout {active |inactive|update}
seconds | type {immediate | normal | permanent}}
Example:
(Optional) Modifies the flow monitor cache parameters
such as timeout values, number of cache entries, and the
cache type.
•
Device(config-flow-monitor)# cache type normal
Step 7 Repeat Step 6 as required to finish modifying the cache
parameters for this flow monitor.
The values for the keywords associated with the
timeout keyword have no effect when the cache
type is set to immediate.
--
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How to Customize Flexible NetFlow Flow Records and Flow Monitors
Command or Action
Step 8 statistics packet protocol
Purpose
(Optional) Enables the collection of protocol
distribution statistics for Flexible NetFlow monitors.
Example:
Device(config-flow-monitor)# statistics packet
protocol
Step 9 statistics packet size
(Optional) Enables the collection of size distribution
statistics for Flexible NetFlow monitors.
Example:
Device(config-flow-monitor)# statistics packet size
Step 10 exporter exporter-name
(Optional) Specifies the name of an exporter that was
created previously.
Example:
Device(config-flow-monitor)# exporter EXPORTER-1
Step 11 end
Exits Flexible NetFlow flow monitor configuration
mode and returns to privileged EXEC mode.
Example:
Device(config-flow-monitor)# end
Step 12 show flow monitor [[name] monitor-name [cache [format
{csv | record | table}]][statistics]]
(Optional) Displays the status and statistics for a
Flexible NetFlow flow monitor.
Example:
Device# show flow monitor FLOW-MONITOR-2 cache
Step 13 show running-config flow monitor monitor-name
(Optional) Displays the configuration of the specified
flow monitor.
Example:
Device# show running-config flow monitor
FLOW_MONITOR-1
Applying a Flow Monitor to an Interface
Before it can be activated, a flow monitor must be applied to at least one interface. To activate a flow
monitor, perform the following required task.
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Customizing Flexible NetFlow Flow Records and Flow Monitors
How to Customize Flexible NetFlow Flow Records and Flow Monitors
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
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 interface type number
Specifies an interface and enters interface
configuration mode.
Example:
Device(config)# interface GigabitEthernet 0/0/0
Step 4 {ip | ipv6} flow monitor monitor-name {input | output}
Activates a flow monitor that was created
previously by assigning it to the interface to
analyze traffic.
Example:
Device(config-if)# ip flow monitor FLOW-MONITOR-1 input
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
Exits interface configuration mode and returns to
privileged EXEC mode.
Example:
Device(config-if)# end
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Example: Configuring a Permanent Flow Record Cache with a Limited Number of Flows
Configuration Examples for Customizing Flow Records and Flow Monitors
Command or Action
Step 7 show flow interface type number
Purpose
Displays the status of Flexible NetFlow (enabled or
disabled) on the specified interface.
Example:
Device# show flow interface GigabitEthernet 0/0/0
Step 8 show flow monitor name monitor-name cache format record
Displays the status, statistics, and flow data in the
cache for the specified flow monitor.
Example:
Device# show flow monitor name FLOW_MONITOR-1 cache
format record
Configuration Examples for Customizing Flow Records and
Flow Monitors
•
•
•
•
•
•
Example: Configuring a Permanent Flow Record Cache with a Limited Number of Flows, page 100
Example: Configuring a Customized Flow Record Cache for Monitoring IPv6 Traffic, page 101
Example: Configuring Flexible NetFlow for Monitoring MAC and VLAN Statistics, page 102
Example: Configuring Flexible NetFlow for Ingress VRF Support, page 102
Example: Configuring Flexible NetFlow for Network-Based Application Recognition, page 103
Example: Configuring Flexible NetFlow for CTS Fields, page 103
Example: Configuring a Permanent Flow Record Cache with a Limited
Number of Flows
The following example is designed to monitor the type of service (ToS) field usage on all interfaces in the
router. An exporter is not configured because this example is intended to be used to capture additional data
for analysis on the router using the show flow monitorcommand.
This sample starts in global configuration mode:
!
ip cef
!
flow record QOS_RECORD
description UD: Flow Record to monitor the use of TOS within this router/network
match interface input
match interface output
match ipv4 tos
collect counter packets
collect counter bytes
exit
!
flow monitor QOS_MONITOR
description UD: Flow Monitor which watches the limited combinations of interface and TOS
record QOS_RECORD
cache type permanent
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Example: Configuring a Customized Flow Record Cache for Monitoring IPv6 Traffic
Configuration Examples for Customizing Flow Records and Flow Monitors
cache entries 8192
! 2^5 (combos of interfaces) * 256 (values of TOS)
exit
!
interface ethernet0/0
ip flow monitor QOS_MONITOR input
exit
!
interface ethernet0/1
ip flow monitor QOS_MONITOR input
exit
!
interface ethernet0/2
ip flow monitor QOS_MONITOR input
exit
!
interface serial2/0
ip flow monitor QOS_MONITOR input
exit
!
interface serial2/1
ip flow monitor QOS_MONITOR input
!
The display from the show flow monitor command shows the current status of the cache.
Router# show flow monitor QOS_MONITOR cache
Cache type:
Permanent
Cache size:
8192
Current entries:
2
High Watermark:
2
Flows added:
2
Updates sent
( 1800 secs)
0
Example: Configuring a Customized Flow Record Cache for Monitoring IPv6
Traffic
The following example creates a customized flow record cache for monitoring IPv6 traffic.
This sample starts in global configuration mode:
!
ip cef
ipv6 cef
!
flow record FLOW-RECORD-2
description Used for basic IPv6 traffic analysis
match ipv6 destination address
collect counter bytes
collect counter packets
!
flow monitor FLOW-MONITOR-2
description Used for basic IPv6 traffic analysis
record FLOW-RECORD-2
cache entries 1000
!
interface GigabitEthernet0/0/0
ipv6 address 2001:DB8:2:ABCD::2/48
ipv6 flow monitor FLOW-MONITOR-2 input
!
interface GigabitEthernet1/0/0
ipv6 address 2001:DB8:3:ABCD::1/48
ipv6 flow monitor FLOW-MONITOR-2 output
!
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Example: Configuring Flexible NetFlow for Monitoring MAC and VLAN Statistics
Configuration Examples for Customizing Flow Records and Flow Monitors
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 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
!
Example: Configuring Flexible NetFlow for Ingress VRF Support
The following example configures the collection of the virtual routing and forwarding (VRF) ID from
incoming packets on a router by applying an input flow monitor having a flow record that collects the VRF
ID as a key field.
This sample starts in global configuration mode:
!
flow record rm_1
match routing vrf input
match ipv4 source address
match ipv4 destination address
collect interface input
collect interface output
collect counter packets
!
flow monitor mm_1
record rm_1
!
interface Serial2/0
ip vrf forwarding green
ip address 172.16.2.2 255.255.255.252
ip flow monitor mm_1 output
!
end
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Example: Configuring Flexible NetFlow for Network-Based Application Recognition
Configuration Examples for Customizing Flow Records and Flow Monitors
Example: Configuring Flexible NetFlow for Network-Based Application
Recognition
The following example uses Network-based Application recognition (NBAR) to create different flows for
each application seen between any two IP hosts by applying a flow monitor having a flow record that
collects the application name as a key field.
This sample starts in global configuration mode:
!
flow record rm_1
match application name
match ipv4 source address
match ipv4 destination address
collect interface input
collect interface output
collect counter packets
!
flow monitor mm_1
record rm_1
!
interface FastEthernet0/0
ip address 172.16.2.2 255.255.255.0
ip flow monitor mm_1 input
!
end
Example: Configuring Flexible NetFlow for CTS Fields
This following example configures the collection of the Cisco TrustSec (CTS) fields, source Security
Group Tag (SGT) and destination Security Group Tag (DGT), in IPv4 traffic.
This sample starts in global configuration mode:
!
flow exporter EXPORTER-1
destination 172.16.10.2
transport udp 90
exit
flow record rm_1
match ipv4 protocol
match ipv4 source address
match ipv4 destination address
match transport source-port
match transport destination-port
match flow direction
match flow cts source group-tag
match flow cts destination group-tag
collect routing source as
collect routing destination as
collect routing source as peer
collect routing destination as peer
collect routing next-hop address ipv4
collect routing next-hop address ipv4 bgp
collect ipv4 source prefix
collect ipv4 source mask
collect ipv4 destination prefix
collect ipv4 destination mask
collect interface input
collect interface output
collect counter bytes
collect counter packets
collect timestamp sys-uptime first
collect timestamp sys-uptime last
!
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Customizing Flexible NetFlow Flow Records and Flow Monitors
Where to Go Next
flow monitor mm_1
record rm_1
exporter EXPORTER-1
!
interface FastEthernet0/0
ip address 172.16.2.2 255.255.255.0
ip flow monitor mm_1 input
!
end
Where to Go Next
If you want to configure data export for Flexible NetFlow, refer to the "Configuring Data Export for Cisco
IOS Flexible NetFlow with Flow Exporters" module.
If you want to configure flow sampling to reduce the CPU overhead of analyzing traffic, refer to the "Using
Cisco IOS Flexible NetFlow Flow Sampling to Reduce the CPU Overhead of Analyzing Traffic" module.
If you want to configure any of the predefined records for Flexible NetFlow, refer to the "Configuring
Cisco IOS Flexible NetFlow with Predefined Records" module.
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Overview of Flexible NetFlow
"Cisco IOS Flexible NetFlow Overview"
Flexible NetFlow Feature Roadmap
"Cisco IOS Flexible NetFlow Features Roadmap"
Emulating original NetFlow with Flexible NetFlow
"Getting Started with Configuring Cisco IOS
Flexible NetFlow"
Configuring flow exporters to export Flexible
NetFlow data.
"Configuring Data Export for Cisco IOS Flexible
NetFlow with Flow Exporters"
Configuring flow sampling to reduce the overhead
of monitoring traffic with Flexible NetFlow
"Using Cisco IOS Flexible NetFlow Flow Sampling
to Reduce the CPU Overhead of Analyzing Traffic"
Configuring Flexible NetFlow using predefined
records
"Configuring Cisco IOS Flexible NetFlow with
Predefined Records"
Using Flexible NetFlow Top N Talkers to analyze
network traffic
"Using Cisco IOS Flexible NetFlow Top N Talkers
to Analyze Network Traffic"
Configuring IPv4 multicast statistics support for
Flexible NetFlow
"Configuring IPv4 Multicast Statistics Support for
Cisco IOS Flexible NetFlow"
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Flexible Netflow Configuration Guide, Cisco IOS Release 15S
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Customizing Flexible NetFlow Flow Records and Flow Monitors
Feature Information for Flexible NetFlow
Standards
Standard
Title
None
--
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:
http://www.cisco.com/go/mibs
RFCs
RFC
Title
RFC 3954
Cisco Systems NetFlow Services Export Version 9
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.
http://www.cisco.com/cisco/web/support/
index.html
Feature Information for Flexible NetFlow
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.
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Customizing Flexible NetFlow Flow Records and Flow Monitors
Feature Information for Flexible NetFlow
Table 26
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow
12.2(33)SRC
Flexible NetFlow is introduced.
12.2(50)SY
Support for this feature was
added for Cisco 7200 series
routers in Cisco IOS Release
12.2(33)SRC.
12.4(9)T
15.0(1)SY
15.0(1)SY1
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The following commands were
introduced or modified: cache
(Flexible NetFlow), clear flow
exporter, clear flow monitor,
clear sampler, collect counter,
collect flow, collect interface,
collect ipv4, collect ipv4
destination, collect ipv4
fragmentation, collect ipv4
section, collect ipv4 source,
collect ipv4 total-length, collect
ipv4 ttl, collect routing, collect
timestamp sys-uptime, collect
transport, collect transport
icmp ipv4, collect transport tcp,
collect transport udp, debug
flow exporter, debug flow
monitor, debug flow record,
debug sampler, description
(Flexible NetFlow), destination,
dscp (Flexible NetFlow),
exporter, flow exporter, flow
monitor, flow platform, flow
record, ip flow monitor, match
flow, match interface (Flexible
NetFlow), match ipv4, match
ipv4 destination, match ipv4
fragmentation, match ipv4
section, match ipv4 source,
match ipv4 total-length, match
ipv4 ttl, match routing, match
transport, match transport
icmp ipv4, match transport tcp,
match transport udp, mode
(Flexible NetFlow), option
(Flexible NetFlow), record,
sampler, show flow exporter,
show flow interface, show flow
monitor, show flow record,
show sampler, source (Flexible
NetFlow), statistics packet,
Customizing Flexible NetFlow Flow Records and Flow Monitors
Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
template data timeout,
transport (Flexible NetFlow).
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.
Flexible NetFlow--Layer 2 Fields 12.2(33)SRE
12.4(22)T
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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Feature Information for Flexible NetFlow
Feature Name
Releases
Feature Information
Flexible NetFlow--IPv6 Unicast
Flows
12.2(33)SRE
Enables Flexible NetFlow to
monitor IPv6 traffic.
12.2(50)SY
12.4(20)T
15.0(1)SY
15.0(1)SY1
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
routing, debug flow record,
match routing, record, show
flow monitor, show flow record,
collect ipv6, collect ipv6
destination, collect ipv6
extension map, collect ipv6
fragmentation, collect ipv6 hoplimit, collect ipv6 length, collect
ipv6 section, collect ipv6 source,
collect transport icmp ipv6,
ipv6 flow monitor, match ipv6,
match ipv6 destination, match
ipv6 extension map, match ipv6
fragmentation, match ipv6 hoplimit, match ipv6 length, match
ipv6 section, match ipv6 source,
match transport icmp ipv6.
Flexible NetFlow--Ingress VRF
Support
12.2(33)SRE
12.2(50)SY
15.0(1)M
15.0(1)SY
15.0(1)SY1
Enables collecting the virtual
routing and forwarding (VRF) ID
from incoming packets on a
router by applying an input flow
monitor having a flow record that
collects the VRF ID as a key or a
nonkey field.
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
routing, match routing, option
(Flexible NetFlow), show flow
monitor.
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Customizing Flexible NetFlow Flow Records and Flow Monitors
Feature Name
Releases
Feature Information
Flexible NetFlow--NBAR
Application Recognition
15.0(1)M
Network-based Application
recognition (NBAR) enables
creation of different flows for
each application seen between
any two IP hosts by applying a
flow monitor having a flow
record that collects the
application name as a key or a
nonkey field.
The following commands were
introduced or modified:
collect application name, match
application name, option
(Flexible NetFlow), show flow
monitor.
TrustSec NetFlow IPv4 SGACL
Deny and Drop Export
12.2(50)SY
15.0(1)SY
15.0(1)SY1
TrustSec NetFlow IPv6 SGACL
Deny and Drop ExportS
12.2(50)SY
15.0(1)SY
15.0(1)SY1
Enables Flexible NetFlow to
collect Cisco Trusted Security
(CTS) information in IPv4 traffic.
The following commands were
introduced or modified: collect
flow, match flow, show flow
monitor.
Enables Flexible NetFlow to
collect Cisco Trusted Security
(CTS) information in IPv6 traffic.
The following commands were
introduced or modified: collect
flow, match flow, show flow
monitor.
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.
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Example: Configuring Flexible NetFlow for CTS Fields
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Using Flexible NetFlow Flow Sampling
This document contains information about and instructions for configuring sampling to reduce the CPU
overhead of analyzing traffic with Flexible NetFlow.
NetFlow is a Cisco technology that provides statistics on packets flowing through a router. NetFlow is the
standard for acquiring IP operational data from IP networks. NetFlow provides data to support network
and security monitoring, network planning, traffic analysis, and IP accounting.
Flexible NetFlow improves on original NetFlow by adding the capability to customize the traffic analysis
parameters for your specific requirements. Flexible NetFlow faciltates the creation of more complex
configurations for traffic analysis and data export through the use of reusable configuration components.
•
•
•
•
•
•
•
Finding Feature Information, page 111
Prerequisites for Using Flow Sampling, page 111
Information About Flexible NetFlow Samplers, page 112
How to Configure Flexible NetFlow Flow Sampling, page 112
Configuration Examples for Using Flexible NetFlow Flow Sampling, page 116
Additional References, page 118
Feature Information for Flexible Netflow—Random Sampling, page 119
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.
Prerequisites for Using Flow Sampling
•
The networking device must be running a Cisco release that supports Flexible NetFlow.
IPv4 Traffic
•
•
The networking device must be configured for IPv4 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding or distributed Cisco Express Forwarding.
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Flow Samplers
Information About Flexible NetFlow Samplers
IPv6 Traffic
•
•
The networking device must be configured for IPv6 routing.
One of the following must be enabled on your router and on any interfaces on which you want to
enable Flexible NetFlow: Cisco Express Forwarding IPv6 or distributed Cisco Express Forwarding
IPv6.
Information About Flexible NetFlow Samplers
•
Flow Samplers, page 112
Flow Samplers
Flow samplers are created as separate components in a router’s configuration. Flow samplers are used to
reduce the load on the device that is running Flexible NetFlow by limiting the number of packets that are
selected for analysis.
Flow sampling exchanges monitoring accuracy for router performance. When you apply a sampler to a
flow monitor, the overhead load on the router of running the flow monitor is reduced because the number
of packets that the flow monitor must analyze is reduced. The reduction in the number of packets that are
analyzed by the flow monitor causes a corresponding reduction in the accuracy of the information stored in
the flow monitor’s cache.
Samplers are combined with flow monitors when they are applied to an interface with the ip flow monitor
command.
How to Configure Flexible NetFlow Flow Sampling
Flow sampling reduces the CPU overhead of analyzing traffic with Flexible NetFlow by reducing the
number of packets that are analyzed.
Note
Only the keywords and arguments required for the Flexible NetFlow commands used in these tasks are
explained in these tasks. For information about the other keywords and arguments available for these
Flexible NetFlow commands, refer to the Cisco IOS Flexible NetFlow Command Reference .
•
•
Configuring a Flow Monitor, page 112
Configuring and Enabling Flow Sampling, page 114
Configuring a Flow Monitor
Samplers are applied to an interface in conjunction with a flow monitor. You must create a flow monitor to
configure the types of traffic that you want to analyze before you can enable sampling. To configure a 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.
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Using Flexible NetFlow Flow Sampling
How to Configure Flexible NetFlow Flow Sampling
Note
You must use the no ip flow monitorcommand 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.
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. end
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Enter your password if prompted.
Example:
Device> enable
Step 2 configure terminal
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 flow monitor monitor-name
Example:
Creates a flow monitor and enters Flexible NetFlow
flow monitor configuration mode.
•
This command also allows you to modify an
existing flow monitor.
Device(config)# flow monitor FLOW-MONITOR-1
Step 4 description description
(Optional) Creates a description for the flow monitor.
Example:
Device(config-flow-monitor)# description Used for
basic traffic analysis
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Configuring and Enabling Flow Sampling
How to Configure Flexible NetFlow Flow Sampling
Command or Action
Purpose
Step 5 record {record-name | netflow-original | netflow {ipv4 | ipv6} Specifies the record for the flow monitor.
record [peer]}
Example:
Device(config-flow-monitor)# record netflow ipv4
original-input
Step 6 end
Exits Flexible NetFlow flow monitor configuration
mode and returns to privileged EXEC mode.
Example:
Device(config-flow-monitor)# end
Configuring and Enabling Flow Sampling
To configure and enable a flow sampler, perform the following required task.
SUMMARY STEPS
1. enable
2. configure terminal
3. sampler sampler-name
4. description description
5. mode {deterministic | random} 1 out-of window-size
6. exit
7. interface type number
8. {ip | ipv6} flow monitor monitor-name [[sampler] sampler-name] {input | output}
9. end
10. show sampler sampler-name
DETAILED STEPS
Command or Action
Step 1 enable
Purpose
Enables privileged EXEC mode.
•
Example:
Device> enable
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Enter your password if prompted.
Using Flexible NetFlow Flow Sampling
How to Configure Flexible NetFlow Flow Sampling
Command or Action
Step 2 configure terminal
Purpose
Enters global configuration mode.
Example:
Device# configure terminal
Step 3 sampler sampler-name
Creates a sampler and enters sampler configuration mode.
•
Example:
This command also allows you to modify an existing
sampler.
Device(config)# sampler SAMPLER-1
Step 4 description description
(Optional) Creates a description for the flow sampler.
Example:
Device(config-sampler)# description Sample at 50%
Step 5 mode {deterministic | random} 1 out-of window-size
Example:
Specifies the sampler mode and the flow sampler window
size.
•
The range for the window-size argument is from 2 to
32,768.
Device(config-sampler)# mode random 1 out-of 2
Step 6 exit
Exits sampler configuration mode and returns to global
configuration mode.
Example:
Device(config-sampler)# exit
Step 7 interface type number
Specifies an interface and enters interface configuration
mode.
Example:
Device(config)# interface GigabitEthernet 0/0/0
Step 8 {ip | ipv6} flow monitor monitor-name [[sampler]
sampler-name] {input | output}
Assigns the flow monitor and the flow sampler that you
created to the interface to enable sampling.
Example:
Device(config-if)# ip flow monitor FLOW-MONITOR-1
sampler SAMPLER-1 input
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Example: Configuring and Enabling a Deterministic Sampler for IPv4 Traffic
Configuration Examples for Using Flexible NetFlow Flow Sampling
Command or Action
Step 9 end
Purpose
Exits interface configuration mode and returns to
privileged EXEC mode.
Example:
Device(config-if)# end
Step 10 show sampler sampler-name
Displays the status and statistics of the flow sampler that
you configured and enabled.
Example:
Device# show sampler SAMPLER-1
Configuration Examples for Using Flexible NetFlow Flow
Sampling
•
•
•
•
Example: Configuring and Enabling a Deterministic Sampler for IPv4 Traffic, page 116
Example: Configuring and Enabling a Deterministic Sampler for IPv6 Traffic, page 117
Example: Adding a Sampler to a Flow Monitor When a Flow Monitor Is Already Enabled, page 117
Example: Removing a Sampler from a Flow Monitor, page 118
Example: Configuring and Enabling a Deterministic Sampler for IPv4 Traffic
The following example shows how to configure and enable deterministic sampling for IPv4 output traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 original-output
exit
!
sampler SAMPLER-1
mode deterministic 1 out-of 2
exit
!
ip cef
!
interface GigabitEthernet 0/0/0
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 sampler SAMPLER-1 output
!
The following example shows how to configure and enable deterministic sampling for IPv4 input traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-1
record netflow ipv4 original-input
exit
!
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Example: Configuring and Enabling a Deterministic Sampler for IPv6 Traffic
Configuration Examples for Using Flexible NetFlow Flow Sampling
sampler SAMPLER-1
mode deterministic 1 out-of 2
exit
!
ip cef
!
interface GigabitEthernet 0/0/0
ip address 172.16.6.2 255.255.255.0
ip flow monitor FLOW-MONITOR-1 sampler SAMPLER-1 input
!
Example: Configuring and Enabling a Deterministic Sampler for IPv6 Traffic
The following example shows how to configure and enable deterministic sampling for IPv6 output traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-2
record netflow ipv6 original-output
exit
!
sampler SAMPLER-1
mode deterministic 1 out-of 2
exit
!
ip cef
ipv6 cef
!
interface GigabitEthernet 0/0/0
ipv6 address 2001:DB8:2:ABCD::2/48
ipv6 flow monitor FLOW-MONITOR-2 sampler SAMPLER-1 output
!
The following example shows how to configure and enable deterministic sampling for IPv6 input traffic.
This sample starts in global configuration mode:
!
flow monitor FLOW-MONITOR-2
record netflow ipv6 original-input
exit
!
sampler SAMPLER-1
mode deterministic 1 out-of 2
exit
!
ip cef
ipv6 cef
!
interface GigabitEthernet 0/0/0
ipv6 address 2001:DB8:2:ABCD::2/48
ipv6 flow monitor FLOW-MONITOR-1 sampler SAMPLER-1 input
!
Example: Adding a Sampler to a Flow Monitor When a Flow Monitor Is
Already Enabled
The following example shows what happens when you try to add a sampler to a flow monitor that has
already been enabled on an interface without a sampler:
Router(config)# interface GigabitEthernet 0/0/0
Router(config-if)# ip flow monitor FLOW-MONITOR-1 sampler SAMPLER-2 input
% Flow Monitor: Flow Monitor 'FLOW-MONITOR-1' is already on in full mode and cannot be
enabled with a sampler.
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Example: Removing a Sampler from a Flow Monitor
Additional References
The following example shows how to remove the flow monitor from the interface so that it can be enabled
with the sampler:
Router(config)# interface GigabitEthernet 0/0/0
Router(config-if)# no ip flow monitor FLOW-MONITOR-1 input
Router(config-if)# ip flow monitor FLOW-MONITOR-1 sampler SAMPLER-2 input
Example: Removing a Sampler from a Flow Monitor
The following example shows what happens when you try to remove a sampler from a flow monitor on an
interface by entering the flow monitor command again without the sampler keyword and argument:
Router(config)# interface GigabitEthernet 0/0/0
Router(config-if)# ip flow monitor FLOW-MONITOR-1 input
% Flow Monitor: Flow Monitor 'FLOW-MONITOR-1' is already on in sampled mode and cannot be
enabled in full mode.
The following example shows how to remove the flow monitor that was enabled with a sampler from the
interface so that it can be enabled without the sampler:
Router(config)# interface GigabitEthernet 0/0/0
Router(config-if)# no ip flow monitor FLOW-MONITOR-1 sampler SAMPLER-2 input
Router(config-if)# ip flow monitor FLOW-MONITOR-1 input
Additional References
Related Documents
Related Topic
Document Title
Cisco IOS commands
Cisco IOS Master Commands List, All Releases
Flexible NetFlow conceptual and configuration
information
Flexible NetFlow Configuration Guide
Configuration commands for Flexible NetFlow
Cisco IOS Flexible NetFlow Command Reference
Standards/RFCs
Standard
Title
No new or modified standards/RFCs are supported
by this feature.
--
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Using Flexible NetFlow Flow Sampling
Feature Information for Flexible Netflow—Random Sampling
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:
http://www.cisco.com/go/mibs
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.
http://www.cisco.com/cisco/web/support/
index.html
Feature Information for Flexible Netflow—Random Sampling
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.
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Using Flexible NetFlow Flow Sampling
Table 27
Feature Information for Flexible Netflow—Random Sampling
Feature Name
Releases
Feature Information
Flexible Netflow—Random
Sampling
12.2(50)SY
Flow samplers are created as
separate components in a router’s
configuration. Flow samplers are
used to reduce the load on the
device that is running Flexible
NetFlow by limiting the number
of packets that are selected for
analysis. Samplers use either
random or deterministic sampling
techniques (modes).
12.4(20)T
Cisco IOS XE Release 3.1S
Cisco IOS XE Release 3.2SE
The following commands were
introduced or modified: clear
sampler, debug sampler ,
mode , record , sampler , show
sampler .
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.
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