Internet Draft
Expiration: February 2004 Editor B. Claise
Document: draft-claise-netflow-9-03.txt Cisco Systems
Category: Informational August 2003
Cisco Systems NetFlow Services Export Version 9
Status of this Memo
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all provisions of Section 10 of RFC2026.
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Abstract
This document specifies the implementation details of the latest
version of the Cisco Systems NetFlow services export format, also
known as the NetFlow version 9 format. This format provides network
administrators with access to IP flows information in a flexible
and extensible way. The distinguishing feature of this new NetFlow
services export format, compared with previous formats, is that it
is template based. The template is a collection of fields, with
corresponding descriptions of their structures and their semantics.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC 2119.
Table of Contents
1. Introduction..................................................2
1.1 Overview..................................................2
1.2 Applications..............................................2
2. Terminology...................................................4
2.1 Terminology Summary Table.................................6
3. NetFlow High-Level Picture on the Exporter....................6
3.1 The NetFlow Process on the Exporter.......................6
3.2 Flow Expiration...........................................6
3.3 Transport Protocol........................................7
4. Packet Layout.................................................7
5. Export Packet Format..........................................8
5.1 Header Format.............................................8
Cisco Systems NetFlow Services Export Version 9 August 2003
5.2 Template FlowSet Format...................................9
5.3 Data FlowSet Format......................................11
6. Options......................................................12
6.1 Options Template FlowSet Format..........................12
6.2 Options Data Record Format...............................14
7. Template Management..........................................15
8. Field Type Definitions.......................................17
9. The Collector Side...........................................21
10. Examples....................................................22
10.1 Packet Header Example...................................22
10.2 Template FlowSet Example................................22
10.3 Data FlowSet Example....................................23
10.4 Options Template FlowSet Example........................24
10.5 Data FlowSet with Options Data Records Example..........25
11. References..................................................25
12. Authors.....................................................26
13. Acknowledgments.............................................26
1. Introduction
1.1 Overview
NetFlow services data can be used for a variety of purposes. A
partial list is provided in the "Application" section. This paper
specifies the most recent version of the NetFlow services flow
record format known as version 9. The distinguishing feature of the
NetFlow version 9 format, compared with previous formats, is that
it is template based. A template is a collection of fields with
corresponding descriptions of their structures and their semantics.
The template-based approach provides the following advantages:
- New fields can be added to NetFlow flow records without
changing the structure of the export record format. With previous
NetFlow versions, adding a new field in the flow record implied a
new version of the export protocol format and a new version of the
NetFlow collector that supported the parsing of the new export
protocol format.
- Templates that are sent to the collector contain the
structural information about the exported flow record fields.
Therefore, if the collector does not understand the semantics of
new fields, it can still interpret the flow record.
- Because the template mechanism is flexible, it allows the
export of only the required fields from the flows to the NetFlow
collector. This helps to reduce the exported flow data volume and
provides possible memory savings for the exporter and collector.
Sending only the required information can also reduce network load.
1.2 Applications
NetFlow services data enables several critical customer
applications:
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Accounting and Billing
NetFlow services data provides fine-grained metering (for example,
flow records include details such as IP addresses, packet and byte
counts, timestamps, Type of Service (ToS), application ports, etc.)
for highly flexible and detailed resource usage accounting. ISPs
can use this information to migrate from single fee, flat-rate
billing to more flexible charging mechanisms based on time of day,
bandwidth usage, application usage, quality of service, etc.
Enterprise customers can use this information for departmental
chargeback or cost allocation for resource usage.
Network Planning
NetFlow services data captured over a long period of time can be
used to track and anticipate network growth and plan upgrades to
increase the number of routing devices, ports, or higher-bandwidth
interfaces. NetFlow services data optimizes both strategic network
planning (peering, backbone upgrade planning, and routing policy
planning) as well as tactical network engineering decisions
(upgrading the router or link capacity). This helps to minimize the
total cost of network operations while maximizing network
performance, capacity, and reliability.
Peering Agreements
NetFlow services data enables ISP peering partners to measure the
volume and characteristics of traffic exchanged with other ISP
peers.
Traffic Engineering
NetFlow services data provides traffic engineering details for a
set of prefixes. This data can be used in network optimization for
load balancing traffic across alternate paths, or for forwarding
traffic of a certain set of prefixes on a preferred route.
Network Monitoring
NetFlow services data enables extensive near real-time network
monitoring capabilities. NetFlow services data analysis can be used
to display traffic patterns associated with routing devices and
switches on an individual or network-wide basis. This can display
traffic- or application-based views and therefore help with
proactive problem detection, efficient troubleshooting, and rapid
problem resolution.
Application Monitoring and Profiling
NetFlow services data enables content and service providers to view
detailed, time-based, and application-based usage of a network.
This information allows planning and allocation of network and
application resources such as Web server, gaming, or multimedia.
User Monitoring and Profiling
NetFlow services data provides a detailed understanding of customer
or end-user usage of network and application resources. This
information can then be used to efficiently plan and allocate
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access, backbone, and application resources, as well as to detect
and resolve potential security and policy violations.
Security Analysis
NetFlow services data provides details on source and destination
addresses, along with the start times of flows and application
ports. This data can be used to analyze network security and
identify network attacks.
NetFlow Data Warehousing and Mining
NetFlow services data (or derived information) can be stored for
later retrieval and analysis to support proactive marketing and
customer service programs. An example of this would be to determine
which applications and services are being used by internal and
external users and then target them for improved service such as
advertising. This is especially useful for ISPs because NetFlow
services data enables them to create better service packaging.
2. Terminology
Various terms used in this document are described in this section.
Note that the terminology summary table in Section 2.1 gives a
quick overview of the relationships between some of the different
terms defined.
Observation Point
An Observation Point is a location in the network where IP packets
can be observed; for example, one or a set of interfaces on a
network device like a router. Every Observation Point is associated
with an Observation Domain.
Observation Domain
The set of Observation Points that is the largest aggregatable set
of flow information at the network device with NetFlow services
enabled is termed an Observation Domain. For example, a router line
card composed of several interfaces with each interface being an
Observation Point.
IP Flow or Flow
An IP Flow, also called a Flow, is defined as a set of IP packets
passing an Observation Point in the network during a certain time
interval. All packets that belong to a particular Flow have a set
of common properties derived from the data contained in the packet
and from the packet treatment at the Observation Point.
Flow Record
A Flow Record provides information about an IP Flow observed at an
Observation Point. In this document, the Flow Data Records are also
referred to as NetFlow services data and NetFlow data.
Exporter
A device (for example, a router) with the NetFlow services enabled,
the Exporter monitors packets entering an Observation Point and
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creates Flows from these packets. The information from these Flows
is exported in the form of Flow Records to the NetFlow Collector.
NetFlow Collector
The NetFlow Collector receives Flow Records from one or more
Exporters. It processes the received Export Packet(s); that is, it
parses and stores the Flow Record information. Flow Records can be
optionally aggregated before being stored on the hard disk.
The NetFlow Collector is also referred to as the Collector in this
document.
Export Packet
An Export Packet is a packet originating at the Exporter that
carries the Flow Records of this Exporter and whose destination is
the NetFlow Collector.
Packet Header
The Packet Header is the first part of an Export Packet. The Packet
Header provides basic information about the packet such as the
NetFlow version, number of records contained within the packet, and
sequence numbering.
Template Record
A Template Record defines the structure and interpretation of
fields in a Flow Data Record.
Flow Data Record
A Flow Data Record is a data record that contains values of the
Flow parameters corresponding to a Template Record.
Options Template Record
An Options Template Record defines the structure and interpretation
of fields in an Options Data Record, including defining how to
scope the applicability of the Options Data Record.
Options Data Record
The data record that contains values and scope information of the
Flow measurement parameters, corresponding to an Options Template
Record.
FlowSet
FlowSet is a generic term for a collection of Flow Records that
have a similar structure. In an Export Packet, one or more FlowSets
follow the Packet Header. There are three different types of
FlowSets: Template FlowSet, Options Template FlowSet, and Data
FlowSet.
Template FlowSet
A Template FlowSet is one or more Template Records that have been
grouped together in an Export Packet.
Options Template FlowSet
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An Options Template FlowSet is one or more Options Template Records
that have been grouped together in an Export Packet.
Data FlowSet
A Data FlowSet is one or more records, of the same type, that are
grouped together in an Export Packet. Each record is either a Flow
Data Record or an Options Data Record previously defined by a
Template Record or an Options Template Record.
2.1 Terminology Summary Table
FlowSet Template Record Data Record
+----------------------------------------------------------------+
| | | Flow Data Record(s) |
| Data FlowSet | / | or |
| | | Options Data Record(s) |
+----------------------------------------------------------------+
| Template FlowSet | Template Record(s) | / |
+----------------------------------------------------------------+
| Options Template | Options Template | / |
| FlowSet | Record(s) | |
+----------------------------------------------------------------+
A Data FlowSet is composed of an Options Data Record(s) or Flow
Data Record(s). No Template Record is included.
A Template Record defines the Flow Data Record, and an Options
Template Record defines the Options Data Record.
A Template FlowSet is composed of Template Record(s). No Flow or
Options Data Record is included.
An Options Template FlowSet is composed of Options Template
Record(s). No Flow or Options Data Record is included.
3. NetFlow High-Level Picture on the Exporter
3.1 The NetFlow Process on the Exporter
The NetFlow process on the Exporter is responsible for the creation
of Flows from the observed IP packets. The details of this process
are beyond the scope of this document.
3.2 Flow Expiration
A Flow is considered to be inactive if no packets belonging to the
Flow have been observed at the Observation Point for a given
timeout. If any packet is seen within the timeout, the flow is
considered an active flow.
A Flow can be exported under the following conditions:
1. If the Exporter can detect the end of a Flow. For example, if
the FIN or RST bit is detected in a TCP [3] connection, the Flow
Record is exported.
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2. If the Flow has been inactive for a certain period of time.
This inactivity timeout SHOULD be configurable, with a minimum
value of 0 for an immediate expiration.
3. For long-lasting Flows, the Exporter SHOULD export the Flow
Records on a regular basis. This timeout SHOULD be configurable.
4. If the Exporter experiences internal constraints, a Flow MAY
be forced to expire prematurely; for example, counters wrapping
or low memory.
3.3 Transport Protocol
To achieve efficiency in terms of processing at the Exporter while
handling high volumes of Export Packets, the NetFlow Export Packets
are encapsulated into UDP [2] datagrams for export to the NetFlow
Collector. However, NetFlow version 9 has been designed to be
transport protocol independent. Hence, it can also operate over
congestion-aware protocols such as TCP [3] or SCTP [4].
Note that the Exporter can export to multiple Collectors, using
independent transport protocols.
4. Packet Layout
An Export Packet consists of a Packet Header followed by one or
more FlowSets. The FlowSets can be any of the possible three types:
Template, Data, or Options Template.
Export Packet:
+--------+-------------------------------------------+
| | +----------+ +---------+ +----------+ |
| Packet | | Template | | Data | | Options | |
| Header | | FlowSet | | FlowSet | | Template | ... |
| | | | | | | FlowSet | |
| | +----------+ +---------+ +----------+ |
+--------+-------------------------------------------+
A FlowSet ID is used to distinguish the different types of
FlowSets. FlowSet IDs lower than 256 are reserved for special
FlowSets, such as the Template FlowSet (ID 0) and the Options
Template FlowSet (ID 1). The Data FlowSets will have a FlowSet ID
greater than 255.
The format of the Template, Data, and Options Template FlowSets
will be discussed later in this document. All fields of the
different FlowSets MUST be coded in network byte order (big-
endian).
Following are some examples of export packets:
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1. An Export Packet consisting of interleaved Template, Data, and
Options Template FlowSets-A newly created Template is exported as
soon as possible. So if there is already an Export Packet with a
Data FlowSet that is being prepared for export, the Template and
Option FlowSets are also interleaved with this information, subject
to availability of space.
Export Packet:
+--------+--------------------------------------------------------+
| | +----------+ +---------+ +-----------+ +---------+ |
| Packet | | Template | | Data | | Options | | Data | |
| Header | | FlowSet | | FlowSet | ... | Template | | FlowSet | |
| | | | | | | FlowSet | | | |
| | +----------+ +---------+ +-----------+ +---------+ |
+--------+--------------------------------------------------------+
2. An Export Packet consisting entirely of Data FlowSetsùAfter the
appropriate Template Records have been defined and transmitted to
the NetFlow Collector device, the majority of Export Packets will
consist solely of Data FlowSets.
Export Packet:
+--------+----------------------------------------------+
| | +---------+ +---------+ +---------+ |
| Packet | | Data | ... | Data | ... | Data | |
| Header | | FlowSet | ... | FlowSet | ... | FlowSet | |
| | +---------+ +---------+ +---------+ |
+--------+----------------------------------------------+
3. An Export Packet consisting entirely of Template and Options
Template FlowSetsùThe Exporter MAY transmit a packet containing
Template and Options Template FlowSets periodically to help ensure
that the NetFlow Collector has the correct Template Records and
Options Template Records when the corresponding Flow Data records
are received.
Export Packet:
+--------+-------------------------------------------------+
| | +----------+ +----------+ +----------+ |
| Packet | | Template | | Template | | Options | |
| Header | | FlowSet | ... | FlowSet | ... | Template | |
| | | | | | | FlowSet | |
| | +----------+ +----------+ +----------+ |
+--------+-------------------------------------------------+
5. Export Packet Format
5.1 Header Format
The Packet Header format in this version is the same as that
defined in the previous versions.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version Number | Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sysUpTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| UNIX Secs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Packet Header Field Descriptions
Version
Version of Flow Record format exported in this packet. The
value of this field is 9 for the current version.
Count
The total number of records in the Export Packet, which is
the sum of Options FlowSet records, Template FlowSet
records, and Data FlowSet records.
SysUpTime
Time in milliseconds since this device was first booted.
Refer to [1].
UNIX Secs
Seconds since 0000 UTC 1970.
Sequence Number
Incremental sequence counter of all Export Packets sent from
the current Observation Domain by the Exporter. This value
will be cumulative, and can be used to identify whether any
Export Packets have been missed.
Source ID
A 32-bit value that identifies the Exporter Observation
Domain. NetFlow Collectors SHOULD use the combination of the
source IP address and the Source ID field to separate
different export streams originating from the same Exporter.
5.2 Template FlowSet Format
One of the essential elements in the NetFlow format is the Template
FlowSet. Templates greatly enhance the flexibility of the Flow
Record format because they allow the NetFlow Collector to process
Flow Records without necessarily knowing the interpretation of all
the data in the Flow Record.
The format of the Template FlowSet is as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 0 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID 1 | Field Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type 1 | Field Length 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type 2 | Field Length 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type N | Field Length N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID 2 | Field Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type 1 | Field Length 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type 2 | Field Length 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Type M | Field Length M |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID K | Field Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Template FlowSet Field Descriptions
FlowSet ID
FlowSet ID value of 0 is reserved for the Template FlowSet.
Length
Total length of this FlowSet. Because an individual Template
FlowSet MAY contain multiple Template Records, the Length
value MUST be used to determine the position of the next
FlowSet record, which could be any type of FlowSet. Length
is the sum of the lengths of the FlowSet ID, the Length
itself, and all Template Records within this FlowSet.
Template ID
Each of the newly generated Template Records is given a
unique Template ID. This uniqueness is local to the
Observation Domain that generated the Template ID.
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Template IDs 0-255 are reserved for Template FlowSets,
Options FlowSets, and other reserved FlowSets yet to be
created. Template IDs of Data FlowSets are numbered from 256
to 65535.
Field Count
Number of fields in this Template Record. Because a Template
FlowSet usually contains multiple Template Records, this
field allows the Collector to determine the end of the
current Template Record and the start of the next.
Field Type
A numeric value that represents the type of the field. Refer
to the "Field Type Definitions" section.
Field Length
The length of the corresponding Field Type, in bytes. Refer
to the "Field Type Definitions" section.
5.3 Data FlowSet Format
The format of the Data FlowSet is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = Template ID | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 1 - Field Value 1 | Record 1 - Field Value 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 1 - Field Value 3 | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 2 - Field Value 1 | Record 2 - Field Value 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 2 - Field Value 3 | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 3 - Field Value 1 | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data FlowSet Field Descriptions
FlowSet ID = Template ID
Each Data FlowSet is associated with a FlowSet ID. The
FlowSet ID maps to a (previously generated) Template ID. The
Collector MUST use the FlowSet ID to find the corresponding
Template Record and decode the Flow Records from the
FlowSet.
Length
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The length of this FlowSet. Length is the sum of the lengths
of the FlowSet ID, Length itself, all Flow Records within
this FlowSet, and the padding bytes, if any.
Record N - Field Value M
The remainder of the Data FlowSet is a collection of Flow
Data Record(s), each containing a set of field values. The
Type and Length of the fields have been previously defined
in the Template Record referenced by the FlowSet ID or
Template ID.
Padding
Padding SHOULD be inserted so that the subsequent FlowSet
starts at a 4-byte aligned boundary. It is important to note
that the Length field includes the padding bits.
Interpretation of the Data FlowSet format can be done only if the
Template FlowSet corresponding to the Template ID is available at
the Collector.
6. Options
6.1 Options Template FlowSet Format
The Options Template Record (and its corresponding Options Data
Record) is used to supply information about the NetFlow process
configuration or NetFlow process specific data, rather than
supplying information about IP Flows.
For example, the Options Template FlowSet can report the sample
rate of a specific interface, if sampling is supported, along with
the sampling method used.
The format of the Options Template FlowSet follows.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 1 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID | Option Scope Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Length | Scope 1 Field Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Scope 1 Field Length | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Scope N Field Length | Option 1 Field Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option 1 Field Length | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option M Field Length | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Options Template FlowSet Field Definitions
FlowSet ID = 1
A FlowSet ID value of 1 is reserved for the Options
Template.
Length
Total length of this FlowSet. Each Options Template FlowSet
MAY contain multiple Options Template Records. Thus, the
Length value MUST be used to determine the position of the
next FlowSet record, which could be either a Template
FlowSet or Data FlowSet.
Length is the sum of the lengths of the FlowSet ID, the
Length itself, and all Options Template Records within this
FlowSet Template ID.
Template ID
Template ID of this Options Template. This value is greater
than 255.
Option Scope Length
The length in bytes of any Scope field definition contained
in the Options Template Record (The use of "Scope" is
described below).
Option Length
The length (in bytes) of any options field definitions
contained in this Options Template Record.
Scope 1 Field Type
The relevant portion of the Exporter/NetFlow process to
which the Options Template Record refers.
Currently defined values are:
1 System
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2 Interface
3 Line Card
4 Cache
5 Template
For example, the NetFlow process can be implemented on a
per-interface basis, so if the Options Template Record were
reporting on how the NetFlow process is configured, the
Scope for the report would be 2 (interface). The associated
interface ID would then be carried in the associated Options
Data FlowSet. The Scope can be limited further by listing
multiple scopes that all must match at the same time. Note
that the Scope fields always precede the Option fields.
Scope 1 Field Length
The length (in bytes) of the Scope field, as it would appear
in an Options Data Record.
Option 1 Field Type
A numeric value that represents the type of field that would
appear in the Options Template Record. Refer to the Field
Type Definitions section.
Option 1 Field Length
The length (in bytes) of the Option field.
Padding
Padding SHOULD be inserted so that the subsequent FlowSet
starts at a 4-byte aligned boundary. It is important to note
that
the Length field includes the padding bits.
6.2 Options Data Record Format
The Options Data Records are sent in Data FlowSets, on a regular
basis, but not with every Flow Data Record. How frequently these
Options Data Records are exported is configurable. See the
"Templates Management" section for more details.
The format of the Data FlowSet containing Options Data Records
follows.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = Template ID | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 1 - Scope 1 Value |Record 1 - Option Field 1 Value|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Record 1 - Option Field 2 Value| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 2 - Scope 1 Value |Record 2 - Option Field 1 Value|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Record 2 - Option Field 2 Value| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record 3 - Scope 1 Value |Record 3 - Option Field 1 Value|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Record 3 - Option Field 2 Value| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Options Data Records of the Data FlowSet Field Descriptions
FlowSet ID = Template ID
A FlowSet ID precedes each group of Options Data Records
within a Data FlowSet. The FlowSet ID maps to a previously
generated Template ID corresponding to this Options Template
Record. The Collector MUST use the FlowSet ID to map the
appropriate type and length to any field values that follow.
Length
The length of this FlowSet.
Length is the sum of the lengths of the FlowSet ID, Length
itself, all the Options Data Records within this FlowSet,
and the padding bytes, if any.
Record N - Option Field M Value
The remainder of the Data FlowSet is a collection of Flow
Records, each containing a set of scope and field values.
The type and length of the fields were previously defined in
the Options Template Record referenced by the FlowSet ID or
Template ID.
Padding
Padding SHOULD be inserted so that the subsequent FlowSet
starts at a 4-byte aligned boundary. It is important to note
that the Length field includes the padding bits.
The Data FlowSet format can be interpreted only if the Options
Template FlowSet corresponding to the Template ID is available at
the Collector.
7. Template Management
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Flow Data records that correspond to a Template Record MAY appear
in the same and/or subsequent Export Packets. The Template Record
is not necessarily carried in every Export Packet. As such, the
NetFlow Collector MUST store the Template Record to interpret the
corresponding Flow Data Records that are received in subsequent
data packets.
A NetFlow Collector that receives Export Packets from several
Observation Domains from the same Exporter MUST be aware that the
uniqueness of the Template ID is not guaranteed across Observation
Domains.
The Template IDs must remain constant for the life of the NetFlow
process on the Exporter. If the Exporter or the NetFlow process
restarts for any reason, all information about Templates will be
lost and new Template IDs will be created. Template IDs are thus
not guaranteed to be consistent across an Exporter or NetFlow
process restart.
A newly created Template record is assigned an unused Template ID
from the Exporter. If the template configuration is changed, the
current Template ID is abandoned and SHOULD NOT be reused until the
NetFlow process or Exporter restarts. If a Collector should receive
a new definition for an already existing Template ID, it MUST
discard the previous template definition and use the new one.
If a configured Template Record on the Exporter is deleted, and re-
configured with exactly the same parameters, the same Template ID
COULD be reused.
The Exporter sends the Template FlowSet and Options Template
FlowSet under the following conditions:
1. After a NetFlow process restarts, the Exporter MUST NOT send any
Data FlowSet without sending the corresponding Template FlowSet
and the required Options Template FlowSet in a previous packet
or including it in the same Export Packet. It MAY transmit the
Template FlowSet and Options Template FlowSet, without any Data
FlowSets, in advance to help ensure that the Collector will have
the correct Template Record before receiving the first Flow or
Options Data Record.
2. In the event of configuration changes, the Exporter SHOULD send
the new template definitions at an accelerated rate. In such a
case, it MAY transmit the changed Template Record(s) and Options
Template Record(s), without any data, in advance to help ensure
that the Collector will have the correct template information
before receiving the first data.
3. On a regular basis, the Exporter MUST send all the Template
Records and Options Template Records to refresh the Collector.
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Template IDs have a limited lifetime at the Collector and MUST
be periodically refreshed.
Two approaches are taken to make sure that Templates get
refreshed at the Collector:
* Every N number of Export Packets.
* On a time basis, so every N number of minutes.
Both options MUST be configurable by the user.
When one of these expiry conditions is met, the Exporter MUST
send the Template FlowSet and Options Template.
8. Field Type Definitions
The following table describes all the field type definitions that
an Exporter MAY support. The fields are a selection of Packet
Header fields, lookup results (for example, the autonomous system
numbers or the subnet masks), and properties of the packet such as
length.
Field Type Value Length Description
(bytes)
Incoming counter with length
IN_BYTES 1 N N x 8 bits for bytes
associated with an IP Flow
Incoming counter with length
IN_PKTS 2 N N x 8 bits for packets
associated with an IP Flow
FLOWS 3 N Number of Flows
that were aggregated;
by default N is 4
PROTOCOL 4 1 IP protocol byte
TOS 5 1 Type of service byte
TCP_FLAGS 6 1 TCP flags; cumulative of all
the TCP flags seen in this
Flow
TCP/UDP source port number
L4_SRC_PORT 7 2 (for example, FTP, Telnet,
or equivalent)
IPV4_SRC_ADDR 8 4 IPv4 source address
SRC_MASK 9 1 Source route mask bits
Input interface index.
INPUT_SNMP 10 N By default N is 2, but
higher values can be used
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TCP/UDP destination port
L4_DST_PORT 11 2 number (for example, FTP,
Telnet, or equivalent)
IPV4_DST_ADDR 12 4 IPv4 destination address
DST_MASK 13 1 Destination route mask bits
Output interface index.
OUTPUT_SNMP 14 N By default N is 2, but
higher values can be used
IPV4_NEXT_HOP 15 4 IPv4 address of the next-hop
router
Source BGP autonomous
SRC_AS 16 N system number where N could
be 2 or 4
Destination BGP autonomous
DST_AS 17 N system number where N could
be 2 or 4
BGP_IPV4_NEXT_HOP 18 4 Next-hop router's IP address
in the BGP domain
IP multicast outgoing
MUL_DST_PKTS 19 N packet counter with length
N x 8 bits for packets
associated with the IP Flow
IP multicast outgoing
MUL_DST_BYTES 20 N Octet (byte) counter with
length N x 8 bits for bytes
associated with the IP Flow
SysUptime at which the
LAST_SWITCHED 21 4 last packet of this Flow
was switched
SysUptime at which the
FIRST_SWITCHED 22 4 first packet of this Flow
was switched
IPV6_SRC_ADDR 27 16 IPv6 source address
IPV6_DST_ADDR 28 16 IPv6 destination address
IPV6_SRC_MASK 29 1 Length of the IPv6 source
mask in contiguous bits
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IPV6_DST_MASK 30 1 Length of the IPv6
destination mask in
contiguous bits
Flow identifier for a given
FLOW_LABEL 31 3 source/destination pair of
IPv6 traffic
Internet Control Message
ICMP_TYPE 32 2 Protocol (ICMP) packet type;
reported as ICMP Type *
256 + ICMP code
IGMP_TYPE 33 1 Internet Group Management
Protocol (IGMP) packet type
When using sampled NetFlow,
the rate at which packets
SAMPLING_INTERVAL 34 4 are sampled; for example, a
value of 100 indicates that
one of every hundred packets
is sampled
The type of algorithm used
for sampled NetFlow:
SAMPLING_ALGO 35 1 1 interval packet
sampling
2 pseudorandom sampling
Timeout value (in seconds)
FLOW_ACTIVE_TIMEOUT 36 2 for active Flow entries in
the NetFlow cache
Timeout value (in seconds)
FLOW_INACTIVE_TIMEOUT 37 2 for inactive Flow entries in
the NetFlow cache
ENGINE_TYPE 38 1 Type of Flow switching
engine
ENGINE_ID 39 1 ID number of the Flow
switching engine
Counter with length
N x 8 bits for bytes
TOTAL_BYTES_EXPORTED 40 N for the number of bytes
exported by the Observation
Domain
Counter with length
N x 8 bits for bytes
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TOTAL_EXP_PKTS_SENT 41 N for the number of packets
exported by the Observation
Domain
Counter with length
N x 8 bits for bytes
TOTAL_FLOWS_EXP 42 N for the number of Flows
exported by the Observation
Domain
Internet Protocol Version
Set to 4 for IPv4, set to 6
IP_PROTOCOL_VERSION 60 1 for IPv6. If not present in
the template, then version 4
is assumed
Flow direction:
DIRECTION 61 1 0 - ingress flow
1 û egress flow
IPV6_NEXT_HOP 62 16 IPv6 address of the next-hop
router
BPG_IPV6_NEXT_HOP 63 16 Next-hop router in the BGP
domain
Bit-encoded field
IPV6_OPTION_HEADERS 64 4 identifying IPv6 option
headers found in the flow
MPLS_LABEL_1 70 3 MPLS label at position 1 in
the stack
MPLS_LABEL_2 71 3 MPLS label at position 2 in
the stack
MPLS_LABEL_3 72 3 MPLS label at position 3 in
the stack
MPLS_LABEL_4 73 3 MPLS label at position 4 in
the stack
MPLS_LABEL_5 74 3 MPLS label at position 5 in
the stack
MPLS_LABEL_6 75 3 MPLS label at position 6 in
the stack
MPLS_LABEL_7 76 3 MPLS label at position 7 in
the stack
MPLS_LABEL_8 77 3 MPLS label at position 8 in
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the stack
MPLS_LABEL_9 78 3 MPLS label at position 9 in
the stack
MPLS_LABEL_10 79 3 MPLS label at position 10
in the stack
The value field is a numeric identifier for the field type.
The following value fields are reserved for Cisco proprietary field
types: 23 to 26, 43 to 59, and 65 to 69.
When extensibility is required, the new field types will be added
to the list. The new field types have to be updated on the Exporter
and Collector but the NetFlow export format would remain unchanged.
Refer to the latest documentation at http://www.cisco.com for the
newly updated list.
All counters and counter-like objects are unsigned integers. In
some cases the optimum size of the counter is implementation
dependent. In these cases the field types are specified as objects
of size N bytes, which should be interpreted as unsigned integers
of size N.
9. The Collector Side
The Collector will receive Template Records from the Exporter,
normally before receiving Flow Data Records (or Options Data
Records). The Flow Data Records (or Options Data Records) can then
be decoded and stored locally on the devices. If the Template
Records have not been received at the time Flow Data Records (or
Options Data Records) are received, the Collector SHOULD store the
Flow Data Records (or Options Data Records) and decode them after
the Template Records are received. A Collector device MUST NOT
assume that the Data FlowSet and the associated Template FlowSet
(or Options Template FlowSet) are exported in the same Export
Packet.
The Collector MUST NOT assume that one and only one Template
FlowSet is present in an Export Packet.
The life of a template at the Collector is limited to a fixed
refresh timeout. Templates not refreshed from the Exporter within
the timeout are expired at the Collector. The Collector MUST NOT
attempt to decode the Flow or Options Data Records with an expired
Template. At any given time the Collector SHOULD maintain the
following for all the current Template Records and Options Template
Records: Exporter, Observation Domain, Template ID, Template
Definition, Last Received.
Note that the Observation Domain is identified by the Source ID
field from the Export Packet.
Template IDs are unique per Exporter and per Observation Domain.
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If the Collector receives a new Template Record (for example, in
the case of an Exporter restart) it MUST immediately override the
existing Template Record.
10. Examples
Let us consider the example of an Export Packet composed of a
Template FlowSet, a Data FlowSet (which contains three Flow Data
Records), an Options Template FlowSet, and a Data FlowSet (which
contains two Options Data Records).
Export Packet:
+--------+---------------------------------------------. . .
| | +--------------+ +-----------------------+
| Packet | | Template | | Data |
| Header | | FlowSet | | FlowSet | . . .
| | | (1 Template) | | (3 Flow Data Records) |
| | +--------------+ +-----------------------+
+--------+---------------------------------------------. . .
. . .+-------------------------------------------------+
+------------------+ +--------------------------+ |
| Options | | Data | |
. . .| Template FlowSet | | FlowSet | |
| (1 Template) | | (2 Options Data Records) | |
+------------------+ +--------------------------+ |
. . .--------------------------------------------------+
10.1 Packet Header Example
The Packet Header is composed of:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version = 9 | Count = 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sysUpTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| UNIX Secs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
10.2 Template FlowSet Example
We want to report the following Field Types:
- The source IP address (IPv4), so the length is 4
- The destination IP address (IPv4), so the length is 4
- The next-hop IP address (IPv4), so the length is 4
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- The number of bytes of the Flow
- The number of packets of the Flow
Therefore, the Template FlowSet will be composed of the following:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 0 | Length = 28 bytes |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID 256 | Field Count = 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP_SRC_ADDR = 8 | Field Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP_DST_ADDR = 12 | Field Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP_NEXT_HOP = 15 | Field Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IN_PKTS = 2 | Field Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IN_BYTES = 1 | Field Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
10.3 Data FlowSet Example
In this example, we report the following three Flow Records:
Src IP addr. | Dst IP addr. | Next Hop addr. | Packet | Bytes
| | | Number | Number
---------------------------------------------------------------
198.168.1.12 | 10.5.12.254 | 192.168.1.1 | 5009 | 5344385
192.168.1.27 | 10.5.12.23 | 192.168.1.1 | 748 | 388934
192.168.1.56 | 10.5.12.65 | 192.168.1.1 | 5 | 6534
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 256 | Length = 64 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 198.168.1.12 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 10.5.12.254 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 192.168.1.1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 5009 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 5344385 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 192.168.1.27 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 10.5.12.23 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 192.168.1.1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 748 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 388934 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 192.168.1.56 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 10.5.12.65 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 192.168.1.1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 6534 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note that padding was not necessary in this example.
10.4 Options Template FlowSet Example
Per line card (the Exporter is composed of two line cards), we want
to report the following Field Types:
- Total number of Export Packets
- Total number of exported Flows
The format of the Options Template FlowSet is as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 1 | Length = 24 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Template ID 257 | Option Scope Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Length = 8 | Scope 1 Field Type = 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Scope 1 Field Length = 2 | TOTAL_EXP_PKTS_SENT = 41 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Length = 4 | TOTAL_FLOWS_EXP = 42 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Field Length = 4 | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
10.5 Data FlowSet with Options Data Records Example
In this example, we report the following two records:
Line Card ID | Export Packet| Export Flow
------------------------------------------
Line Card 1 | 345 | 10201
Line Card 2 | 690 | 20402
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FlowSet ID = 257 | Length = 14 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 1 | 345 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 10201 | 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 2 | 690 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 20402 | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
11. References
[1] R. Presuhn et al, "Management Information Base (MIB) for the
Simple Network Management Protocol (SNMP)" RFC 3418, December 2002
[2] J. Postel, "User Datagram Protocol" RFC 768, August 1980
[3] "TRANSMISSION CONTROL PROTOCOL DARPA INTERNET PROGRAM PROTOCOL
SPECIFICATION" RFC 793, September 1981
[4] R. Stewart et al, "Stream Control Transmission Protocol" RFC
2960, October 2000
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12. Authors
This document was jointly written by Vamsidhar Valluri, Martin
Djernaes, Ganesh Sadasivan, and Benoit Claise.
13. Acknowledgments
I would like to thank Pritam Shah, Paul Kohler and Stewart Bryant
for their valuable technical feedback.
Authors Addresses
Benoit Claise
Cisco Systems
De Kleetlaan 6a b1
1831 Diegem
Belgium
Phone: +32 2 704 5622
E-mail: bclaise@cisco.com
Ganesh Sadasivan
Cisco Systems, Inc.
3750 Cisco Way
San Jose, CA 95134
USA
Phone: +1 408 527-0251
E-mail: gsadasiv@cisco.com
Vamsi Valluri
Cisco Systems, Inc.
510 McCarthy Blvd.
San Jose, CA 95035
USA
Phone: +1 408 525-1835
E-mail: vvalluri@cisco.com
Martin Djernaes
Cisco Systems, Inc.
510 McCarthy Blvd.
San Jose, CA 95035
USA
Phone: +1 408 853-1676
E-mail: djernaes@cisco.com
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