]> Orange

mohamed.boucadair@orange.com

Huawei

benoit.claise@huawei.com

Operations and Management OPSAWG IPFIX This document provides simple fixes to the IANA IP Flow Information Export (IPFIX) registry. Specifically, this document provides updates to fix a shortcoming in the description of some Information Elements (IE), updates to ensure a consistent structure when calling an existing IANA registry, and updates to fix broken pointers, orphan section references, etc. The updates are also meant to bringing some consistency among the entries of the registry. Discussion Venues Discussion of this document takes place on the Operations and Management Area Working Group Working Group mailing list (opsawg@ietf.org), which is archived at . Source for this draft and an issue tracker can be found at .

Introduction As the OPSAWG is currently considering which updates , the WG realized that some other parts of the IANA IP Flow Information Export (IPFIX) registry were not up-to-date. Indeed, since its initial creation in 2007, some IPFIX Information Elements (IEs) are not adequately specified any longer (while they were at some point in time in the past). This document intends to update the IANA registry and bringing some consistency among the entries of the registry. As discussed with IANA, the "Additional Information" entry in should contain a link to an existing registry, when applicable, as opposed to having:

• A link to an exiting registry in the "Description" entry.
• The registry detailed values repeated in the "Description" entry. This practice has the drawback that the description must be updated each time the registry is updated.

Therefore, this document lists a set of simple fixes to the IPFIX IANA registry . These fixes are classified as follows:

• Updates that fix a shortcoming in the description of an IE ().
• Updates that require adding a pointer to an existing IANA registry ().
• Updates that are meant to ensure a consistent structure when calling an existing IANA registry ().
• Miscellaneous updates that fix broken pointers, orphan section references, etc. ().

These updates are also meant to facilitate the automatic extraction of the values maintained in IANA registries (e.g., with a cron job), required by Collectors to be able to support new IPFIX IEs and, more importantly, adequately interpret new values in registries specified by those IPFIX IEs. Note that, as per , is the normative reference for the IPFIX IEs that were defined in . Therefore, the updates in this document do not update any part of . Likewise, this document is not marked as formally updating , , , , , , , , , , and .

Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here. This document uses the IPFIX-specific terminology (Information Element, Template, Collector, Data Record, Flow Record, Exporting Process, Collecting Process, etc.) defined in Section 2 of . As in , these IPFIX-specific terms have the first letter of a word capitalized.

Why An RFC is Needed for These Updates? Many of the edits in this document may be handled by the IPFIX Experts (informally called the IE-DOCTORS ). However, and given that many of the impacted IEs were created via the IETF stream, the following from should be followed:

• This process should not in any way be construed as allowing the IE-DOCTORS to overrule IETF consensus. Specifically, Information Elements in the IANA IE registry that were added with IETF consensus require IETF consensus for revision or deprecation.

Update the Description

ipv6ExtensionHeaders Information Element

Issues The current specification of the ipv6ExtensionHeaders Information Element should be updated to:

1. Reflect missing IPv6 EHs, specifically 139, 140, 253, and 254.
2. Specify how to automatically update the registry when a new value is assigned in .
3. Update the 108 entry given that 108 does not correspond to an extension header as per .
4. Specify the procedure to follow when all bits are exhausted.

specifies fixes to the first three issues. specifies a new Information Element to fix the last issue. Other Information Elements are defined in to address some other limitations such as lack of reporting of extension header chains or aggregate extension headers length. Note that some implementations may not be able to export all observed extension headers in a Flow because of a hardware or software limit (see, e.g., . The specification of the ipv6ExtensionHeaders Information Element does not discuss whether it covers all enclosed extension headers or only up to a limit. A solution to this shortcoming is also defined in .

Updates to the ipv6ExtensionHeaders Description

• OLD:

• NEW:

Description:

IPv6 extension headers observed in packets of this Flow. The information is encoded in a set of bit fields. For each IPv6 option header, there is a bit in this set. The bit is set to 1 if any observed packet of this Flow contains the corresponding IPv6 extension header. Otherwise, if no observed packet of this Flow contained the respective IPv6 extension header, the value of the corresponding bit is 0. The IPv6 extension header associated with each bit is provided in [NEW_IPFIX_IPv6EH_SUBREGISTRY]. The following drawing indicates the position of each bit in the encoding of the Information Element.

This IE is used only when the observed extension headers are in the 0-31 range.

If the observed EHs exceeds that range, ipv6ExtensionHeadersFull Information Element MUST be used .

Abstract Data Type:

unsigned32

Data Type Semantics:

flags

ElementId:

64

Status:

current

Reference:

This-Document

Additional Information:

See the assigned bits to each IPv6 extension header in [NEW_IPFIX_IPv6EH_SUBREGISTRY].

See for the general definition of IPv6 extension headers and for assigned extension headers.

tcpOptions

Issues Only options having a kind =< 63 can be included in a tcpOptions IE. An update is thus required to specify how any observed TCP option in a packet can be exported using IPFIX. Also, there is no way to report the observed Experimental Identifiers (ExIDs) that are carried in shared TCP options (kind=253 or 254) . The following section updates the description of the tcpOptions IE to explicitly indicate the applicable kind range and to point to the new IEs defined in .

Update the Description of the tcpOptions IE This document requests IANA to update the description of the tcpOptions IE in as follows:

• OLD Description:

  TCP options in packets of this Flow. The information is encoded in a set of bit fields. For each TCP option, there is a bit in this set. The bit is set to 1 if any observed packet of this Flow contains the corresponding TCP option. Otherwise, if no observed packet of this Flow contained the respective TCP option, the value of the corresponding bit is 0. Options are mapped to bits according to their option numbers. Option number X is mapped to bit X. TCP option numbers are maintained by IANA.

• NEW Description:

  TCP options in packets of this Flow. The information is encoded in a set of bit fields. For each TCP option, there is a bit in this set. The bit is set to 1 if any observed packet of this Flow contains the corresponding TCP option. Otherwise, if no observed packet of this Flow contained the respective TCP option, the value of the corresponding bit is 0. Options are mapped to bits according to the drawing below. TCP option numbers are maintained by IANA. This information element is used only when the observed kinds are within the 0-63 range. If not, the tcpOptionsFull IE MUST be used.

forwardingStatus The current forwardingStatus entry in deviates from what is provided in . In particular, the registered Abstract Data Type is unsigned8, while it must be unsigned32. The following update fixes that issue. The description is also updated to clarify the use of the reduced-size encoding as per .

• OLD:

Forward 000000 -> No further information value : 0x89 = 137 binary: 10001001 decode: 10 -> Drop 001001 -> Bad TTL - Additional Information: See "NetFlow Version 9 Flow-Record Format" (CCO-NF9FMT). - Abstract Data Type: unsigned8 ]]>

• NEW:

Forward 000000 -> No further information value : 0x89 = 137 binary: 10001001 decode: 10 -> Drop 001001 -> Bad TTL - Additional Information: See the Forwarding Status sub-registries at https://www.iana.org/assignments/ipfix/ipfix.xhtml#forwarding-status. - Abstract Data Type: unsigned32 ]]>

Point to An Existing IANA Registry This document requests IANA to update the following entries by adding the indicated "Additional Information" to the registry: Cite an IANA Registry under Additional Information

IE	Additional Information
icmpTypeCodeIPv4	https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml
igmpType	https://www.iana.org/assignments/igmp-type-numbers/igmp-type-numbers.xhtml#igmp-type-numbers-1
icmpTypeCodeIPv6	https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml
icmpTypeIPv4	https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-types
icmpCodeIPv4	https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-codes
icmpTypeIPv6	https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml#icmpv6-parameters-2
icmpCodeIPv6	https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml#icmpv6-parameters-3
privateEnterpriseNumber	https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers

Consistent Citation of IANA Registries This document requests IANA to update for each of the IE entries listed in the following subsections.

mplsTopLabelType

• OLD:

  • Description:

    This field identifies the control protocol that allocated the top-of-stack label. Values for this field are listed in the MPLS label type registry.

    See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-mpls-label-type.

  • Additional Information:

    See for the MPLS label structure.

    See the list of MPLS label types assigned by IANA at [https://www.iana.org/assignments/mpls-label-values].

• NEW:

  • Description:

    This field identifies the control protocol that allocated the top-of-stack label. Values for this field are listed in the MPLS label type registry.

  • Additional Information:

    See the list of MPLS label types assigned by IANA at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-mpls-label-type].

    See for the MPLS label structure.

classificationEngineId

• OLD:

  • Description:

    A unique identifier for the engine that determined the Selector ID. Thus, the Classification Engine ID defines the context for the Selector ID. The Classification Engine can be considered a specific registry for application assignments.

    Values for this field are listed in the Classification Engine IDs registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#classification-engine-ids.

  • Additional Information:
• NEW:

  • Description:

    A unique identifier for the engine that determined the Selector ID. Thus, the Classification Engine ID defines the context for the Selector ID. The Classification Engine can be considered a specific registry for application assignments.

    Values for this field are listed in the Classification Engine IDs registry.

  • Additional Information:

    See https://www.iana.org/assignments/ipfix/ipfix.xhtml#classification-engine-ids.

flowEndReason

• OLD:

  • Description:

    The reason for Flow termination. Values are listed in the flowEndReason registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-flow-end-reason.

  • Additional Information:
• NEW:

  • Description:

    The reason for Flow termination. Values are listed in the flowEndReason registry.

  • Additional Information:

    See the Classification Engine IDs registry available at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-flow-end-reason].

natOriginatingAddressRealm

• OLD:

  • Description:

    Indicates whether the session was created because traffic originated in the private or public address realm. postNATSourceIPv4Address, postNATDestinationIPv4Address, postNAPTSourceTransportPort, and postNAPTDestinationTransportPort are qualified with the address realm in perspective.

    Values are listed in the natOriginatingAddressRealm registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-originating-address-realm.

  • Additional Information:

    See for the definition of NAT.

• NEW:

  • Description:

    Indicates whether the session was created because traffic originated in the private or public address realm. postNATSourceIPv4Address, postNATDestinationIPv4Address, postNAPTSourceTransportPort, and postNAPTDestinationTransportPort are qualified with the address realm in perspective.

    Values are listed in the natOriginatingAddressRealm registry.

  • Additional Information:

    See the assigned NAT originating address realm at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-originating-address-realm]. See for the definition of NAT.

natEvent

• OLD:

  • Description:

    This Information Element identifies a NAT event. This IE identifies the type of a NAT event. Examples of NAT events include, but are not limited to, NAT translation create, NAT translation delete, Threshold Reached, or Threshold Exceeded, etc. Values for this Information Element are listed in the "NAT Event Type" registry, see https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-event-type.

  • Additional Information:

    See for the definition of NAT.

    See for the definition of middleboxes.

    See for the definitions of values 4-16.

• NEW:

  • Description:

    This Information Element identifies a NAT event. This IE identifies the type of a NAT event. Examples of NAT events include, but are not limited to, NAT translation create, NAT translation delete, Threshold Reached, or Threshold Exceeded, etc. Values for this Information Element are listed in the "NAT Event Type" registry.

  • Additional Information:

    See the assigned NAT Event Types at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-event-type].

    See for the definition of NAT.

    See for the definition of middleboxes.

    See for the definitions of values 4-16.

firewallEvent

• OLD:

  • Description:

    Indicates a firewall event. Allowed values are listed in the firewallEvent registry.

    See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-firewall-event.

  • Additional Information:
• NEW:

  • Description:

    Indicates a firewall event. Allowed values are listed in the firewallEvent registry.

  • Additional Information:

    See the assigned firewall events at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-firewall-event].

biflowDirection

• OLD:

  • Description:

    A description of the direction assignment method used to assign the Biflow Source and Destination. This Information Element MAY be present in a Flow Data Record, or applied to all flows exported from an Exporting Process or Observation Domain using IPFIX Options. If this Information Element is not present in a Flow Record or associated with a Biflow via scope, it is assumed that the configuration of the direction assignment method is done out-of-band. Note that when using IPFIX Options to apply this Information Element to all flows within an Observation Domain or from an Exporting Process, the Option SHOULD be sent reliably. If reliable transport is not available (i.e., when using UDP), this Information Element SHOULD appear in each Flow Record. Values are listed in the biflowDirection registry. See [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-biflow-direction].

  • Additional Information:
• NEW:

  • Description:

    A description of the direction assignment method used to assign the Biflow Source and Destination. This Information Element MAY be present in a Flow Data Record, or applied to all flows exported from an Exporting Process or Observation Domain using IPFIX Options. If this Information Element is not present in a Flow Record or associated with a Biflow via scope, it is assumed that the configuration of the direction assignment method is done out-of-band. Note that when using IPFIX Options to apply this Information Element to all flows within an Observation Domain or from an Exporting Process, the Option SHOULD be sent reliably. If reliable transport is not available (i.e., when using UDP), this Information Element SHOULD appear in each Flow Record. Values are listed in the biflowDirection registry.

  • Additional Information:

    See the assigned biflow direction values at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-biflow-direction].

observationPointType

• OLD:

  • Description:

    Type of observation point. Values are listed in the observationPointType registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-observation-point-type.

  • Additional Information:
• NEW:

  • Description:

    Type of observation point. Values are listed in the observationPointType registry.

  • Additional Information:

    See the assigned observation point type at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-observation-point-type].

anonymizationTechnique

• OLD:

  • Description:

    A description of the anonymization technique applied to a referenced Information Element within a referenced Template. Each technique may be applicable only to certain Information Elements and recommended only for certain Information Elements. Values are listed in the anonymizationTechnique registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-anonymization-technique.

  • Additional Information:
• NEW:

  • Description:

    A description of the anonymization technique applied to a referenced Information Element within a referenced Template. Each technique may be applicable only to certain Information Elements and recommended only for certain Information Elements. Values are listed in the anonymizationTechnique registry.

  • Additional Information:

    See the assigned anonymization techniques at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-anonymization-technique].

natType

• OLD:

  • Description:

    Values are listed in the natType registry.

    See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-type.

  • Additional Information:

    See for the definition of NAT.

    See for the definition of NAT44.

    See for the definition of NAT64.

    See for the definition of NAT46.

    See for the definition of NAT66.

    See for the definition of IPv4.

    See for the definition of IPv6.

• NEW:

  • Description:

    Values are listed in the natType registry.

  • Additional Information:

    See the assigned NAT types at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-type].

    See for the definition of NAT.

    See for the definition of NAT44.

    See for the definition of NAT46.

    See for the definition of NAT64.

    See for the definition of NPTv6.

    See for the definition of IPv4.

    See for the definition of IPv6.

• Note: This change also corrects errors in the pointers provided NAT46/NAT64.

selectorAlgorithm

• OLD:

  • Description:

    This Information Element identifies the packet selection methods (e.g., Filtering, Sampling) that are applied by the Selection Process. Most of these methods have parameters. Further Information Elements are needed to fully specify packet selection with these methods and all their parameters. The methods listed below are defined in . For their parameters, Information Elements are defined in the information model document. The names of these Information Elements are listed for each method identifier. Further method identifiers may be added to the list below. It might be necessary to define new Information Elements to specify their parameters.

    The following packet selection methods identifiers are defined here: https://www.iana.org/assignments/psamp-parameters.

    There is a broad variety of possible parameters that could be used for Property match Filtering (5) but currently there are no agreed parameters specified.

  • Additional Information:
• NEW:

  • Description:

    This Information Element identifies the packet selection methods (e.g., Filtering, Sampling) that are applied by the Selection Process. Most of these methods have parameters. Further Information Elements are needed to fully specify packet selection with these methods and all their parameters. For the methods parameters, Information Elements are defined in the information model document. The names of these Information Elements are listed for each method identifier. Further method identifiers may be added to the list. It might be necessary to define new Information Elements to specify their parameters.

    There is a broad variety of possible parameters that could be used for Property match Filtering (5) but currently there are no agreed parameters specified.

  • Additional Information:

    See the assigned PSAMP parameters at [https://www.iana.org/assignments/psamp-parameters].

informationElementDataType

• OLD:

  • Description:

    A description of the abstract data type of an IPFIX information element.These are taken from the abstract data types defined in section 3.1 of the IPFIX Information Model ; see that section for more information on the types described in the [informationElementDataType] subregistry. These types are registered in the IANA IPFIX Information Element Data Type subregistry. This subregistry is intended to assign numbers for type names, not to provide a mechanism for adding data types to the IPFIX Protocol, and as such requires a Standards Action to modify.

  • Additional Information:
• NEW:

  • Description:

    A description of the abstract data type of an IPFIX information element.These are taken from the abstract data types defined in Section 3.1 of the IPFIX Information Model ; see that section for more information on the types described in the [informationElementDataType] subregistry. These types are registered in the IANA IPFIX Information Element Data Type subregistry.

    The [informationElementDataType] subregistry is intended to assign numbers for type names, not to provide a mechanism for adding data types to the IPFIX Protocol, and as such requires a Standards Action to modify.

  • Additional Information:

    See the assigned emelement data types at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-information-element-data-types].

informationElementSemantics

• OLD:

  • Description:

    A description of the semantics of an IPFIX Information Element. These are taken from the data type semantics defined in section 3.2 of the IPFIX Information Model ; see that section for more information on the types defined in the [IPFIX Information Element Semantics] subregistry. This field may take the values in the semantics registry; the special value 0x00 (default) is used to note that no semantics apply to the field; it cannot be manipulated by a Collecting Process or File Reader that does not understand it a priori. These semantics are registered in the IANA IPFIX Information Element Semantics subregistry. This subregistry is intended to assign numbers for semantics names, not to provide a mechanism for adding semantics to the IPFIX Protocol, and as such requires a Standards Action to modify.

  • Additional Information:
• NEW:

  • Description:

    A description of the semantics of an IPFIX Information Element. These are taken from the data type semantics defined in Section 3.2 of the IPFIX Information Model ; see that section for more information on the types defined in the [IPFIX Information Element Semantics] subregistry. This field may take the values in the [IPFIX Information Element Semantics] subregistry; the special value 0x00 (default) is used to note that no semantics apply to the field; it cannot be manipulated by a Collecting Process or File Reader that does not understand it a priori.

    The [IPFIX Information Element Semantics] subregistry is intended to assign numbers for semantics names, not to provide a mechanism for adding semantics to the IPFIX Protocol, and as such requires a Standards Action to modify.

  • Additional Information:

    See the assigned semantics of an IPFIX Information Element at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-information-element-semantic].

informationElementUnits

• OLD:

  • Description:

    A description of the units of an IPFIX Information Element. These correspond to the units implicitly defined in the Information Element definitions in section 5 of the IPFIX Information Model ; see that section for more information on the types described in the informationElementsUnits subregistry. This field may take the values in Table 3 below; the special value 0x00 (none) is used to note that the field is unitless. These types are registered in the [IANA IPFIX Information Element Units] subregistry.

  • Additional Information:
• NEW:

  • Description:

    A description of the units of an IPFIX Information Element. These correspond to the units implicitly defined in the Information Element definitions in Section 5 of the IPFIX Information Model ; see that section for more information on the types described in the informationElementsUnits subregistry. These types can take the values in the [IANA IPFIX Information Element Units] subregistry. The special value 0x00 (none) is used to note that the field is unitless.

  • Additional Information: See the assigned units of an IPFIX Information Element at [IANA IPFIX Information Element Units].

portRangeStart

• OLD:

  • Description:

    The port number identifying the start of a range of ports. A value of zero indicates that the range start is not specified, ie the range is defined in some other way.

    Additional information on defined TCP port numbers can be found at https://www.iana.org/assignments/service-names-port-numbers.

  • Additional Information:
• NEW:

  • Description:

    The port number identifying the start of a range of ports. A value of zero indicates that the range start is not specified, i.e., the range is defined in some other way.

  • Additional Information:

    Additional information on defined TCP port numbers can be found at https://www.iana.org/assignments/service-names-port-numbers.

portRangeEnd

• OLD:

  • Description:

    The port number identifying the end of a range of ports. A value of zero indicates that the range end is not specified, ie the range is defined in some other way. Additional information on defined TCP port numbers can be found at https://www.iana.org/assignments/service-names-port-numbers.

  • Additional Information:
• NEW:

  • Description:

    The port number identifying the end of a range of ports. A value of zero indicates that the range end is not specified, i.e., the range is defined in some other way.

  • Additional Information:

    Additional information on defined TCP port numbers can be found at https://www.iana.org/assignments/service-names-port-numbers.

ingressInterfaceType

• OLD:

  • Description:

    The type of interface where packets of this Flow are being received. The value matches the value of managed object 'ifType' as defined in https://www.iana.org/assignments/ianaiftype-mib.

  • Additional Information:

    https://www.iana.org/assignments/ianaiftype-mib

• NEW:

  • Description:

    The type of interface where packets of this Flow are being received. The value matches the value of managed object 'ifType'.

  • Additional Information:

    See the assigned ingress interface types at [https://www.iana.org/assignments/ianaiftype-mib].

egressInterfaceType

• OLD:

  • Description:

    The type of interface where packets of this Flow are being sent. The value matches the value of managed object 'ifType' as defined in https://www.iana.org/assignments/ianaiftype-mib.

  • Additional Information:

    https://www.iana.org/assignments/ianaiftype-mib

• NEW:

  • Description:

    The type of interface where packets of this Flow are being sent. The value matches the value of managed object 'ifType'.

  • Additional Information:

    See the assigned egress interface types at [https://www.iana.org/assignments/ianaiftype-mib].

valueDistributionMethod

• OLD:

  • Description:

    A description of the method used to distribute the counters from Contributing Flows into the Aggregated Flow records described by an associated scope, generally a Template. The method is deemed to apply to all the non-key Information Elements in the referenced scope for which value distribution is a valid operation; if the originalFlowsInitiated and/or originalFlowsCompleted Information Elements appear in the Template, they are not subject to this distribution method, as they each infer their own distribution method. The valueDistributionMethod registry is intended to list a complete set of possible value distribution methods.

    See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-value-distribution-method.

  • Additional Information:
• NEW:

  • Description:

    A description of the method used to distribute the counters from Contributing Flows into the Aggregated Flow records described by an associated scope, generally a Template. The method is deemed to apply to all the non-key Information Elements in the referenced scope for which value distribution is a valid operation; if the originalFlowsInitiated and/or originalFlowsCompleted Information Elements appear in the Template, they are not subject to this distribution method, as they each infer their own distribution method. The valueDistributionMethod registry is intended to list a complete set of possible value distribution methods.

  • Additional Information:

    See the assigned distributed methods at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-value-distribution-method].

flowSelectorAlgorithm

• OLD:

  • Description:

    This Information Element identifies the Intermediate Flow Selection Process technique (e.g., Filtering, Sampling) that is applied by the Intermediate Flow Selection Process. Most of these techniques have parameters. Its configuration parameter(s) MUST be clearly specified. Further Information Elements are needed to fully specify packet selection with these methods and all their parameters. Further method identifiers may be added to the flowSelectorAlgorithm registry. It might be necessary to define new Information Elements to specify their parameters.

    Please note that the purpose of the flow selection techniques described in this document is the improvement of measurement functions as defined in the Scope (Section 1).

    The Intermediate Flow Selection Process Techniques identifiers are defined at https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-flowselectoralgorithm.

  • Additional Information:
• NEW:

  • Description:

    This Information Element identifies the Intermediate Flow Selection Process technique (e.g., Filtering, Sampling) that is applied by the Intermediate Flow Selection Process. Most of these techniques have parameters. Its configuration parameter(s) MUST be clearly specified. Further Information Elements are needed to fully specify packet selection with these methods and all their parameters. Further method identifiers may be added to the flowSelectorAlgorithm registry. It might be necessary to define new Information Elements to specify their parameters.

  • Additional Information:

    See the assigned flow selector algorithms at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-flowselectoralgorithm].

dataLinkFrameType

• OLD:

  • Description:

    This Information Element specifies the type of the selected data link frame. Data link types are defined in the dataLinkFrameType registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-data-link-frame-type.

    Further values may be assigned by IANA. Note that the assigned values are bits so that multiple observations can be OR'd together. The data link layer is defined in [ISO/IEC.7498-1:1994].

  • Additional Information:

    (IEEE802.3)(IEEE802.11)(ISO/IEC.7498-1:1994)

• NEW:

  • Description:

    This Information Element specifies the type of the selected data link frame. Data link types are defined in the dataLinkFrameType registry.

    Further values may be assigned by IANA. Note that the assigned values are bits so that multiple observations can be OR'd together.

  • Additional Information:

    See the assigned data link frame types at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-data-link-frame-type].

    More information about the data link layer can be found in (IEEE802.3)(IEEE802.11)(ISO/IEC.7498-1:1994).

mibCaptureTimeSemantics

• OLD:

  • Description:

    Indicates when in the lifetime of the Flow the MIB value was retrieved from the MIB for a mibObjectIdentifier. This is used to indicate if the value exported was collected from the MIB closer to Flow creation or Flow export time and refers to the Timestamp fields included in the same Data Record.

    This field SHOULD be used when exporting a mibObjectValue that specifies counters or statistics. If the MIB value was sampled by SNMP prior to the IPFIX Metering Process or Exporting Process retrieving the value (i.e., the data is already stale) and it is important to know the exact sampling time, then an additional observationTime* element should be paired with the OID using IPFIX Structured Data . Similarly, if different MIB capture times apply to different mibObjectValue elements within the Data Record, then individual mibCaptureTimeSemantics Information Elements should be paired with each OID using IPFIX Structured Data.

    Values are listed in the mibCaptureTimeSemantics registry. See https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-mib-capture-time-semantics.

  • Additional Information:
• NEW:

  • Description:

    Indicates when in the lifetime of the Flow the MIB value was retrieved from the MIB for a mibObjectIdentifier. This is used to indicate if the value exported was collected from the MIB closer to Flow creation or Flow export time and refers to the Timestamp fields included in the same Data Record.

    This field SHOULD be used when exporting a mibObjectValue that specifies counters or statistics. If the MIB value was sampled by SNMP prior to the IPFIX Metering Process or Exporting Process retrieving the value (i.e., the data is already stale) and it is important to know the exact sampling time, then an additional observationTime* element should be paired with the OID using IPFIX Structured Data . Similarly, if different MIB capture times apply to different mibObjectValue elements within the Data Record, then individual mibCaptureTimeSemantics Information Elements should be paired with each OID using IPFIX Structured Data.

    Values are listed in the mibCaptureTimeSemantics registry.

  • Additional Information:

    See the assigned values for the MIB capture time semantics at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-mib-capture-time-semantics].

natQuotaExceededEvent

• OLD:

  • Description:

    This Information Element identifies the type of a NAT Quota Exceeded event. Values for this Information Element are listed in the "NAT Quota Exceeded Event Type" registry, see https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-quota-exceeded-event.

  • Additional Information:

    See for the definition of the IPv4 source address field.

    See for the definition of NAT.

    See for the definition of middleboxes.

• NEW:

  • Description:

    This Information Element identifies the type of a NAT Quota Exceeded event. Values for this Information Element are listed in the "NAT Quota Exceeded Event Type" registry.

  • Additional Information:

    See the assigned events for exceeded NAT quota at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-quota-exceeded-event].

    See for the definition of the IPv4 source address field.

    See for the definition of NAT.

    See for the definition of middleboxes.

natThresholdEvent

• OLD:

  • Description:

    This Information Element identifies a type of a NAT Threshold event. Values for this Information Element are listed in the "NAT Threshold Event Type" registry, see https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-threshold-event.

  • Additional Information:

    See for the definition of the IPv4 source address field.

    See for the definition of NAT.

    See for the definition of middleboxes.

• NEW:

  • Description:

    This Information Element identifies a type of a NAT Threshold event. Values for this Information Element are listed in the "NAT Threshold Event Type" registry.

  • Additional Information:

    See the assigned values for the NAT Threshold events at [https://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-nat-threshold-event].

    See for the definition of the IPv4 source address field.

    See for the definition of NAT.

    See for the definition of middleboxes.

Misc This document requests IANA to update the description of the following entries in .

collectionTimeMilliseconds

• OLD:

  • Description:

    The absolute timestamp at which the data within the scope containing this Information Element was received by a Collecting Process. This Information Element SHOULD be bound to its containing IPFIX Message via IPFIX Options and the messageScope Information Element, as defined below.

• NEW:

  • Description:

    The absolute timestamp at which the data within the scope containing this Information Element was received by a Collecting Process. This Information Element SHOULD be bound to its containing IPFIX Message via IPFIX Options and the messageScope Information Element.

messageMD5Checksum

• OLD:

  • Description:

    The MD5 checksum of the IPFIX Message containing this record. This Information Element SHOULD be bound to its containing IPFIX Message via an options record and the messageScope Information Element, as defined below, and SHOULD appear only once in a given IPFIX Message. To calculate the value of this Information Element, first buffer the containing IPFIX Message, setting the value of this Information Element to all zeroes. Then calculate the MD5 checksum of the resulting buffer as defined in , place the resulting value in this Information Element, and export the buffered message.

    This Information Element is intended as a simple checksum only; therefore collision resistance and algorithm agility are not required, and MD5 is an appropriate message digest. This Information Element has a fixed length of 16 octets.

• NEW:

  • Description:

    The MD5 checksum of the IPFIX Message containing this record. This Information Element SHOULD be bound to its containing IPFIX Message via an options record and the messageScope Information Element, and SHOULD appear only once in a given IPFIX Message. To calculate the value of this Information Element, first buffer the containing IPFIX Message, setting the value of this Information Element to all zeroes. Then calculate the MD5 checksum of the resulting buffer as defined in , place the resulting value in this Information Element, and export the buffered message.

    This Information Element is intended as a simple checksum only; therefore collision resistance and algorithm agility are not required, and MD5 is an appropriate message digest. This Information Element has a fixed length of 16 octets.

anonymizationFlags

• OLD:

• NEW:

informationElementDescription

• OLD:

  • Description:

    A UTF-8 encoded Unicode string containing a human-readable description of an Information Element. The content of the informationElementDescription MAY be annotated with one or more language tags , encoded in-line within the UTF-8 string, in order to specify the language in which the description is written. Description text in multiple languages MAY tag each section with its own language tag; in this case, the description information in each language SHOULD have equivalent meaning. In the absence of any language tag, the "i-default" language SHOULD be assumed.

    See the Security Considerations section for notes on string handling for Information Element type records.

• NEW:

  • Description:

    A UTF-8 encoded Unicode string containing a human-readable description of an Information Element. The content of the informationElementDescription MAY be annotated with one or more language tags , encoded in-line within the UTF-8 string, in order to specify the language in which the description is written. Description text in multiple languages MAY tag each section with its own language tag; in this case, the description information in each language SHOULD have equivalent meaning. In the absence of any language tag, the "i-default" language SHOULD be assumed.

    See the Security Considerations Section of for notes on string handling for Information Element type records.

distinctCountOfDestinationIPAddress

• OLD:

  • Description:

    The count of distinct destination IP address values for Original Flows contributing to this Aggregated Flow, without regard to IP version. This Information Element is preferred to the version-specific counters below, unless it is important to separate the counts by version.

• NEW:

  • Description:

    The count of distinct destination IP address values for Original Flows contributing to this Aggregated Flow, without regard to IP version. This Information Element is preferred to the version-specific counters, unless it is important to separate the counts by version.

externalAddressRealm

• OLD:

  • Description:

    This Information Element represents the external address realm where the packet is originated from or destined to. The detailed definition is in the internal address realm as specified above.

• NEW:

  • Description:

    This Information Element represents the external address realm where the packet is originated from or destined to.

    See the internalAddressRealm IE for the detailed definition.

Security Considerations IPFIX security considerations are discussed in .

IANA Considerations Sections 4 to 7 include actions for IANA. These actions are not repeated here. This document also requests IANA to update the reference clause of the "IPFIX Information Elements" registry with the reference to this document.

IPFIX Subregistry for IPv6 Extension Headers This document requests IANA to create a new registry entitled "ipv6ExtensionHeaders Bits" under the IANA IPFIX registry group . When a new code is assigned to an IPv6 EH in , a free bit is selected by IANA for this EH from "ipv6ExtensionHeaders Bits" registry and the registry is updated with the details that mirror the assigned EH. The "Label" mirrors the "keyword" of an EH as indicated in , while the "Protocol Number" mirrors the "Protocol Number" in . IANA is requested to add the following note to :

• Note:

  When a new code is assigned to an IPv6 Extension Header, a free bit in [NEW_IPFIX_IPv6EH_SUBREGISTRY] is selected for this new Extension Header. >>[NEW_IPFIX_IPv6EH_SUBREGISTRY] is updated accordingly. Modifications to existing registrations must be mirrored in [NEW_IPFIX_IPv6EH_SUBREGISTRY].

• Note to the RFC Editor: Please replace [NEW_IPFIX_IPv6EH_SUBREGISTRY] with the link used by IANA for this new registry.

Otherwise, the registration policy for the registry is Expert Review (). See more details in . The initial values of this registry are as follows:

Guidelines for the Designated Experts It is suggested that multiple designated experts be appointed for registry change requests. Criteria that should be applied by the designated experts include determining whether the proposed registration duplicates existing entries and whether the registration description is clear and fits the purpose of this registry. Within the review period, the designated experts will either approve or deny the registration request, communicating this decision to the IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.

References Normative References n.d. n.d. n.d. This document defines the data types and management policy for the information model for the IP Flow Information Export (IPFIX) protocol. This information model is maintained as the IANA "IPFIX Information Elements" registry, the initial contents of which were defined by RFC 5102. This information model is used by the IPFIX protocol for encoding measured traffic information and information related to the traffic Observation Point, the traffic Metering Process, and the Exporting Process. Although this model was developed for the IPFIX protocol, it is defined in an open way that allows it to be easily used in other protocols, interfaces, and applications. This document obsoletes RFC 5102. This document specifies the IP Flow Information Export (IPFIX) protocol, which serves as a means for transmitting Traffic Flow information over the network. In order to transmit Traffic Flow information from an Exporting Process to a Collecting Process, a common representation of flow data and a standard means of communicating them are required. This document describes how the IPFIX Data and Template Records are carried over a number of transport protocols from an IPFIX Exporting Process to an IPFIX Collecting Process. This document obsoletes RFC 5101. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This document provides guidelines for how to write definitions of new Information Elements for the IP Flow Information Export (IPFIX) protocol. It provides instructions on using the proper conventions for Information Elements to be registered in the IANA IPFIX Information Element registry, and provides guidelines for expert reviewers to evaluate new registrations. Orange Huawei This document specifies new IP Flow Information Export (IPFIX) Information Elements (IEs) to solve some issues with existing ipv6ExtensionHeaders and tcpOptions IPFIX IEs, especially the ability to export any observed IPv6 extension headers or TCP options. This document describes how the experimental TCP option codepoints can concurrently support multiple TCP extensions, even within the same connection, using a new IANA TCP experiment identifier. This approach is robust to experiments that are not registered and to those that do not use this sharing mechanism. It is recommended for all new TCP options that use these codepoints. Many protocols make use of points of extensibility that use constants to identify various protocol parameters. To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper. For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA). To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed. This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry. This is the third edition of this document; it obsoletes RFC 5226. Informative References This document describes an efficient method for exporting bidirectional flow (Biflow) information using the IP Flow Information Export (IPFIX) protocol, representing each Biflow using a single Flow Record. [STANDARDS-TRACK] This document describes anonymization techniques for IP flow data and the export of anonymized data using the IP Flow Information Export (IPFIX) protocol. It categorizes common anonymization schemes and defines the parameters needed to describe them. It provides guidelines for the implementation of anonymized data export and storage over IPFIX, and describes an information model and Options- based method for anonymization metadata export within the IPFIX protocol or storage in IPFIX Files. This document defines an Experimental Protocol for the Internet community. This document specifies a protocol which allows nodes to remain reachable while moving around in the IPv6 Internet. Each mobile node is always identified by its home address, regardless of its current point of attachment to the Internet. While situated away from its home, a mobile node is also associated with a care-of address, which provides information about the mobile node's current location. IPv6 packets addressed to a mobile node's home address are transparently routed to its care-of address. The protocol enables IPv6 nodes to cache the binding of a mobile node's home address with its care-of address, and to then send any packets destined for the mobile node directly to it at this care-of address. To support this operation, Mobile IPv6 defines a new IPv6 protocol and a new destination option. All IPv6 nodes, whether mobile or stationary, can communicate with mobile nodes. [STANDARDS-TRACK] This document describes an updated version of the IP Authentication Header (AH), which is designed to provide authentication services in IPv4 and IPv6. This document obsoletes RFC 2402 (November 1998). [STANDARDS-TRACK] This document describes an updated version of the Encapsulating Security Payload (ESP) protocol, which is designed to provide a mix of security services in IPv4 and IPv6. ESP is used to provide confidentiality, data origin authentication, connectionless integrity, an anti-replay service (a form of partial sequence integrity), and limited traffic flow confidentiality. This document obsoletes RFC 2406 (November 1998). [STANDARDS-TRACK] Orange RFC 7125 revised the tcpControlBits IP Flow Information Export (IPFIX) Information Element that was originally defined in RFC 5102 to reflect changes to the TCP header control bits since RFC 793. However, that update is still problematic for interoperability because some flag values have subsequently been deprecated. This document removes stale information from the IPFIX registry and avoids future conflicts with the authoritative TCP Header Flags registry. This document obsoletes RFC 7125. This document revises the tcpControlBits IP Flow Information Export (IPFIX) Information Element as originally defined in RFC 5102 to reflect changes to the TCP Flags header field since RFC 793. This memo defines an information model for the IP Flow Information eXport (IPFIX) protocol. It is used by the IPFIX protocol for encoding measured traffic information and information related to the traffic Observation Point, the traffic Metering Process, and the Exporting Process. Although developed for the IPFIX protocol, the model is defined in an open way that easily allows using it in other protocols, interfaces, and applications. [STANDARDS-TRACK] This memo defines an information model for the Packet SAMPling (PSAMP) protocol. It is used by the PSAMP protocol for encoding sampled packet data and information related to the Sampling process. As the PSAMP protocol is based on the IP Flow Information eXport (IPFIX) protocol, this information model is an extension to the IPFIX information model. [STANDARDS-TRACK] This document describes an extension to the IP Flow Information Export (IPFIX) protocol, which is used to represent and transmit data from IP flow measurement devices for collection, storage, and analysis, to allow the encoding of IPFIX Information Model properties within an IPFIX Message stream. This enables the export of extended type information for enterprise-specific Information Elements and the storage of such information within IPFIX Files, facilitating interoperability and reusability among a wide variety of applications and tools. [STANDARDS-TRACK] This document describes a file format for the storage of flow data based upon the IP Flow Information Export (IPFIX) protocol. It proposes a set of requirements for flat-file, binary flow data file formats, then specifies the IPFIX File format to meet these requirements based upon IPFIX Messages. This IPFIX File format is designed to facilitate interoperability and reusability among a wide variety of flow storage, processing, and analysis tools. [STANDARDS TRACK] This document specifies a Cisco Systems extension to the IPFIX information model specified in RFC 5102 to export application information. This document is not an Internet Standards Track specification; it is published for informational purposes. The Intermediate Flow Selection Process is the process of selecting a subset of Flows from all observed Flows. The Intermediate Flow Selection Process may be located at an IP Flow Information Export (IPFIX) Exporter or Collector, or within an IPFIX Mediator. It reduces the effort of post-processing Flow data and transferring Flow Records. This document describes motivations for using the Intermediate Flow Selection process and presents Intermediate Flow Selection techniques. It provides an information model for configuring Intermediate Flow Selection Process techniques and discusses what information about an Intermediate Flow Selection Process should be exported. This document provides a common implementation-independent basis for the interoperable application of the IP Flow Information Export (IPFIX) protocol to the handling of Aggregated Flows, which are IPFIX Flows representing packets from multiple Original Flows sharing some set of common properties. It does this through a detailed terminology and a descriptive Intermediate Aggregation Process architecture, including a specification of methods for Original Flow counting and counter distribution across intervals. This document describes Information Elements related to the data link layer. They are used by the IP Flow Information Export (IPFIX) protocol for encoding measured data link layer traffic information. This document describes some additional IP Flow Information Export (IPFIX) Information Elements in the range of 1-127, which is the range compatible with field types used by NetFlow version 9 in RFC 3954, as specified in the IPFIX Information Model in RFC 7012. This document specifies a way to complement IP Flow Information Export (IPFIX) Data Records with Management Information Base (MIB) objects, avoiding the need to define new IPFIX Information Elements for existing MIB objects that are already fully specified. Two IPFIX Options Templates, as well as a method for creating IPFIX Options Templates that are used to export the extra data required to fully describe Simple Network Management Protocol (SNMP) MIB objects in IPFIX, are specified herein. Network operators require NAT devices to log events like creation and deletion of translations and information about the resources that the NAT device is managing. In many cases, the logs are essential to identify an attacker or a host that was used to launch malicious attacks and for various other purposes of accounting. Since there is no standard way of logging this information, different NAT devices use proprietary formats; hence, it is difficult to expect consistent behavior. This lack of standardization makes it difficult to write the Collector applications that would receive this data and process it to present useful information. This document describes the formats for logging NAT events. SiPanda This specification defines various limits that may be applied to receiving, sending, and otherwise processing packets that contain IPv6 extension headers. The need for such limits is pragmatic to facilitate interoperability amongst hosts and routers in the presence of extension headers, thereby increasing the feasibility of deployment of extension headers. The limits described herein establish the minimum baseline of support for use of extension headers on the Internet. If it is known that all communicating parties for a particular communication, including destination hosts and any routers in the path, are capable of supporting more than the baseline then these default limits may be freely exceeded. This document specifies the architecture for Multiprotocol Label Switching (MPLS). [STANDARDS-TRACK] The NAT operation described in this document extends address translation introduced in RFC 1631 and includes a new type of network address and TCP/UDP port translation. In addition, this document corrects the Checksum adjustment algorithm published in RFC 1631 and attempts to discuss NAT operation and limitations in detail. This memo provides information for the Internet community. This document is intended as part of an IETF discussion about "middleboxes" - defined as any intermediary box performing functions apart from normal, standard functions of an IP router on the data path between a source host and destination host. This document establishes a catalogue or taxonomy of middleboxes, cites previous and current IETF work concerning middleboxes, and attempts to identify some preliminary conclusions. It does not, however, claim to be definitive. This memo provides information for the Internet community. This memo proposes another short-term solution, address reuse, that complements CIDR or even makes it unnecessary. The address reuse solution is to place Network Address Translators (NAT) at the borders of stub domains. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. This note describes a framework for IPv4/IPv6 translation. This is in the context of replacing Network Address Translation - Protocol Translation (NAT-PT), which was deprecated by RFC 4966, and to enable networks to have IPv4 and IPv6 coexist in a somewhat rational manner while transitioning to an IPv6 network. This document is not an Internet Standards Track specification; it is published for informational purposes. This document describes a stateless, transport-agnostic IPv6-to-IPv6 Network Prefix Translation (NPTv6) function that provides the address-independence benefit associated with IPv4-to-IPv4 NAT (NAPT44) and provides a 1:1 relationship between addresses in the "inside" and "outside" prefixes, preserving end-to-end reachability at the network layer. This document defines an Experimental Protocol for the Internet community. This document specifies version 6 of the Internet Protocol (IPv6). It obsoletes RFC 2460. This document describes Sampling and Filtering techniques for IP packet selection. It provides a categorization of schemes and defines what parameters are needed to describe the most common selection schemes. Furthermore, it shows how techniques can be combined to build more elaborate packet Selectors. The document provides the basis for the definition of information models for configuring selection techniques in Metering Processes and for reporting the technique in use to a Collector. [STANDARDS-TRACK] This document specifies an extension to the IP Flow Information Export (IPFIX) protocol specification in RFC 5101 and the IPFIX information model specified in RFC 5102 to support hierarchical structured data and lists (sequences) of Information Elements in data records. This extension allows definition of complex data structures such as variable-length lists and specification of hierarchical containment relationships between Templates. Finally, the semantics are provided in order to express the relationship among multiple list elements in a structured data record. [STANDARDS-TRACK] This document describes the MD5 message-digest algorithm. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. This memo provides information for the Internet community. It does not specify an Internet standard. ISO/IEC 10646-1 defines a large character set called the Universal Character Set (UCS) which encompasses most of the world's writing systems. The originally proposed encodings of the UCS, however, were not compatible with many current applications and protocols, and this has led to the development of UTF-8, the object of this memo. UTF-8 has the characteristic of preserving the full US-ASCII range, providing compatibility with file systems, parsers and other software that rely on US-ASCII values but are transparent to other values. This memo obsoletes and replaces RFC 2279. This document describes the structure, content, construction, and semantics of language tags for use in cases where it is desirable to indicate the language used in an information object. It also describes how to register values for use in language tags and the creation of user-defined extensions for private interchange. This document, in combination with RFC 4647, replaces RFC 3066, which replaced RFC 1766. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. This document proposed a mechanism for language tagging in plain text. This memo provides information for the Internet community. This document is the current policies being applied by the Internet Engineering Steering Group (IESG) towards the standardization efforts in the Internet Engineering Task Force (IETF) in order to help Internet protocols fulfill these requirements. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

Acknowledgments Thanks to Paul Aitken for the review. Special thanks to Andrew Feren for sharing data about scans of IPFIX data he collected. Thomas Graf tagged an issue with the forwardingStatus Information Element. Thanks to Eric Vyncke for the review and comments. Thanks to Qin Wu for the opsdir review and Behcet Sarikay for the genart review.