]> Nippon Telegraph and Telephone Corporation

1-5-1 Otemachi Chiyoda-ku Tokyo 100-8116 Japan +81 3 6838 5267 kashima@nttv6.net

Nippon Telegraph and Telephone East Corporation

3-19-2 Nishi-shinjuku Shinjuku-ku Tokyo 163-8019 Japan +81 3 5359 4351 akoba@nttv6.net

Cisco Systems, Inc.

96 Commercial Quay Commercial Street Edinburgh EH6 6LX United Kingdom +44 131 561 3616 paitken@cisco.com

IP Flow Information Export 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.

Ethernet and VLAN (Virtual LAN) technologies had been used only in Local Area Networks. Recently, they have been used in Wide Area Networks, e.g., Layer 2 VPN (L2 VPN) services. Accordingly, carrier networks using VLAN technologies have been enhanced to Provider Bridged Networks and Provider Backbone Bridged Networks. In addition, Ethernet in data centers has also been enhanced for server virtualization and input/output (I/O) consolidation. While these innovations provide flexibility, scalability, and mobility to an existing network architecture, they increase the complexity of traffic measurement due to the existence of various Ethernet header formats. To cope with this, a more sophisticated method of traffic measurement is required. IPFIX and Packet Sampling (PSAMP) help to resolve these problems. However, the PSAMP Information Model and the IPFIX Information Model don't yet contain enough Information Elements related to the data link layer, e.g., Ethernet header forms. This document describes existing and new Information Elements related to data link layers that enable a more sophisticated traffic measurement method. Note that this document does not update or because IANA's IPFIX registry is the ultimate Information Element reference, per Section 1 of .

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.

Provider Bridge and Provider Backbone Bridge, which are standards for Wide-Area Ethernet, are described below. In Provider Bridge, there are two VLAN IDs: Service VLAN Identifier (S-VID) and Customer VLAN Identifier (C-VID). S-VID is assigned to an Ethernet frame by a service provider, while C-VID is independently assigned to an Ethernet frame by a customer. Frame switching in a service provider network is based on only S-VID. In Provider Backbone Bridge, new Ethernet fields, such as Backbone VLAN Identifier (B-VID) and Backbone Service Instance Identifier (I-SID), are introduced to overcome the limitations on the VLAN identifier space and to isolate the service provider and customer identifier spaces. Frame switching is based on a 12-bit B-VID, and customer identification is based on a 24-bit I-SID. A flexible network design has become possible because network management is separated from customer management. Other Ethernet fields that indicate quality of service (QoS) class are Backbone VLAN Priority Code Point (B-PCP), Backbone VLAN Drop Eligible Indicator (B-DEI), Backbone Service Instance Priority Code Point (I-PCP), and Backbone Service Instance Drop Eligible Indicator (I-DEI). The Provider Backbone Bridge technologies have enhanced a Wide-Area Ethernet service from a flat network to a hierarchical network consisting of a Provider Bridged Network and Provider Backbone Bridged Network. Frame formats used in Wide-Area Ethernet are shown in .

There have been several challenges in the existing virtual switches environment in a data center. One is the lack of network management visibility: limited features on virtual switches make it difficult to monitor traffic among virtual machines (VMs). Another is the lack of management scalability and flexibility: increasing the number of VMs for multi-tenant architecture causes an increase in the number of virtual switches and in the number of the traffic control policies, which reach the limitations of network management scalability and flexibility. In this situation, the IEEE 802.1 working group is standardizing virtual bridging technologies such as Edge Virtual Bridging (EVB), including two kinds of Edge Relays: Virtual Edge Bridge (VEB) and Virtual Edge Port Aggregator (VEPA) . The VEB is a bridge that provides bridging among multiple VMs and the external bridging environment. The VEPA is a bridge-like device on a host that forwards all internal traffic to the adjacent EVB bridge and then distributes any traffic received from the adjacent EVB bridge to VMs. The VEPA makes all the VM-to-VM traffic visible to the EVB bridge so that the traffic can be monitored and so that the EVB bridge can apply filtering to the traffic. To improve flexibility, a virtual link between a host system and EVB bridge is standardized as S-channel. S-channel allows a bridge to treat the traffic in the virtual link as if it comes in on a separate port. For example, in the host, an S-channel may be attached to a VEB or a VEPA or directly to an internal port in order to apply each port-based filtering rule to the traffic. S-channel over the link between a host and its adjacent bridge uses Service VLAN Tag (S-TAG) . When S-channel is in use, frames on the link carry an S-TAG to identify the S-channel. On the other hand, Bridge Port Extension emulates single Extended Bridge from multiple physical switches and virtual switches, and it also simplifies network management. Also, it solves the lack of network management visibility by forwarding all traffic into a central Controlling Bridge using E-channel. E-channel over the link between a Bridge Port Extender and a Controlling Bridge uses E-TAG defined in . Traffic monitoring over S-channel and E-channel is required in order to get visibility of VM-to-VM traffic and visibility of each channel's traffic on a virtual link. Frame formats with E-TAG used in E-channel and S-TAG used in S-channel are shown in .  Though these frames carry special tags while on the link, those tags identify a virtual port (or for multicast in the downstream direction, a set of virtual ports) to which they are destined. These tag values only have local meaning, and the Flow would be reported as sent and arriving on the corresponding virtual ports. Therefore, IPFIX does not need to monitor data based on these tags.

The Information Elements listed in the upper section of Table 1 are necessary for enabling IPFIX and PSAMP traffic measurement for the data link layer, which is not limited to Ethernet because the method can be applied to other data link protocols as well. Information Elements in the middle section of Table 1 are necessary for enabling the IPFIX and PSAMP traffic measurement for . Information Elements in the lower section of Table 1 are octet counter or packet length for layer 2, and they are necessary for enabling IPFIX and PSAMP traffic measurement for the data link layer.

Some existing Information Elements are required for data link layer export. Their details are reproduced here from IANA's IPFIX registry . Additions per this document appear between *. introduces the missing Data Type Semantics for the dataLinkFrameSize Information Element, which is held to be an interoperable change per #4 in Section 5.2 of . extends the definition of the dataLinkFrameSection Information Element with reference to the new sectionOffset Information Element, which is also an interoperable change per #4 in Section 5.2 of . The layer2OctetDeltaCount Information Element reports the number of layer 2 octets since the previous report in incoming packets for this Flow, while the layer2OctetTotalCount Information Element reports the total number of layer 2 octets in incoming packets for this Flow. The layer2FrameDeltaCount Information Element reports the number of incoming layer 2 frames since the previous report for this Flow, while layer2FrameTotalCount Information Element reports the total number of incoming layer 2 frames for this Flow. All of these Information Elements are unchanged from the existing IANA definitions, and are reproduced in through below for completeness. Therefore, these changes do not introduce any backward-compatibility issues. Per Section 5.2 of , for each of these changes, [RFC7133] has been appended to the requester in IANA's IPFIX registry , the Information Element's revision number has been incremented by one, and the Information Element's revision date column has been updated.

Description: This Information Element specifies the length of the selected data link frame. The data link layer is defined in . Abstract Data Type: unsigned16 *Data Type Semantics: quantity* ElementId: 312 References: Status: current

Description: This Information Element carries n octets from the data link frame of a selected frame, starting sectionOffset octets into the frame. *However, if no sectionOffset field corresponding to this Information Element is present, then a sectionOffset of zero applies, and the octets MUST be from the start of the data link frame.* The sectionExportedOctets expresses how much data was observed, while the remainder is padding. When the sectionExportedOctets field corresponding to this Information Element exists, this Information Element MAY have a fixed length and MAY be padded, or it MAY have a variable length. When the sectionExportedOctets field corresponding to this Information Element does not exist, this Information Element SHOULD have a variable length and MUST NOT be padded. In this case, the size of the exported section may be constrained due to limitations in the IPFIX protocol. Further Information Elements, i.e., dataLinkFrameType and dataLinkFrameSize, are needed to specify the data link type and the size of the data link frame of this Information Element. A set of these Information Elements MAY be contained in a structured data type, as expressed in . Or a set of these Information Elements MAY be contained in one Flow Record as shown in of [RFC7133]. The data link layer is defined in . Abstract Data Type: octetArray ElementId: 315 References: [RFC7133] Status: current

The layer2OctetDeltaCount Information Element is unchanged from the existing IANA definition and is reproduced here for reference only. Description The number of layer 2 octets since the previous report (if any) in incoming packets for this Flow at the Observation Point. The number of octets includes layer 2 header(s) and layer 2 payload. Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter Units: octets ElementId: 352 Status: current

The layer2OctetTotalCount Information Element is unchanged from the existing IANA definition and is reproduced here for reference only. Description: The total number of layer 2 octets in incoming packets for this Flow at the Observation Point since the Metering Process (re-)initialization for this Observation Point. The number of octets includes layer 2 header(s) and layer 2 payload. Abstract Data Type: unsigned64 Data Type Semantics: totalCounter Units: octets ElementId: 353 Status: current

The layer2FrameDeltaCount Information Element is unchanged from the existing IANA definition and is reproduced here for reference only. Description: The number of incoming layer 2 frames since the previous report (if any) for this Flow at the Observation Point. Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter Units: frames ElementId: 430 Status: current

The layer2FrameTotalCount Information Element is unchanged from the existing IANA definition and is reproduced here for reference only. Description: The total number of incoming layer 2 frames for this Flow at the Observation Point since the Metering Process (re-)initialization for this Observation Point. Abstract Data Type: unsigned64 Data Type Semantics: totalCounter Units: frames ElementId: 431 Status: current

The following new Information Elements have been added for data link layer monitoring. In IANA's IPFIX registry , the Requester has been set to [RFC7133], the Information Element's Revision has been set to zero, and the Information Element's Date set to the date upon which the new Information Elements have been added to the registry. All other columns that are not explicitly mentioned below (e.g., Units, Range, References) are not applicable and are to be left blank since the registry does not explicitly record "not applicable".

Description: This Information Element specifies the type of the selected data link frame. The following data link types are defined here: - 0x01 IEEE802.3 ETHERNET - 0x02 IEEE802.11 MAC Frame format 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 . Abstract Data Type: unsigned16 Data Type Semantics: flags ElementId: 408 References: Status: current

Description: This Information Element specifies the offset of the packet section (e.g., dataLinkFrameSection, ipHeaderPacketSection, ipPayloadPacketSection, mplsLabelStackSection, and mplsPayloadPacketSection). If this Information Element is omitted, it defaults to zero (i.e., no offset). If multiple sectionOffset Information Elements are specified within a single Template, then they apply to the packet section Information Elements in order: the first sectionOffset applies to the first packet section, the second to the second, and so on. Note that the "closest" sectionOffset and packet section Information Elements within a given Template are not necessarily related. If there are fewer sectionOffset Information Elements than packet section Information Elements, then subsequent packet section Information Elements have no offset, i.e., a sectionOffset of zero applies to those packet section Information Elements. If there are more sectionOffset Information Elements than the number of packet section Information Elements, then the additional sectionOffset Information Elements are meaningless. Abstract Data Type: unsigned16 Data Type Semantics: quantity ElementId: 409 Status: current

Description: This Information Element specifies the observed length of the packet section (e.g., dataLinkFrameSection, ipHeaderPacketSection, ipPayloadPacketSection, mplsLabelStackSection, and mplsPayloadPacketSection) when padding is used. The packet section may be of a fixed size larger than the sectionExportedOctets. In this case, octets in the packet section beyond the sectionExportedOctets MUST follow the rules for padding (i.e., be composed of zero (0) valued octets). Abstract Data Type: unsigned16 Data Type Semantics: quantity ElementId: 410 References: Status: current

Description: This Information Element, which is 16 octets long, represents the Backbone Service Instance Tag (I-TAG) Tag Control Information (TCI) field of an Ethernet frame as described in . It encodes the Backbone Service Instance Priority Code Point (I-PCP), Backbone Service Instance Drop Eligible Indicator (I-DEI), Use Customer Addresses (UCAs), Backbone Service Instance Identifier (I-SID), Encapsulated Customer Destination Address (C-DA), Encapsulated Customer Source Address (C-SA), and reserved fields. The structure and semantics within the Tag Control Information field are defined in . Abstract Data Type: octetArray Data Type Semantics: default ElementId: 411 References: Status: current

Description: The value of the 24-bit Backbone Service Instance Identifier (I-SID) portion of the Backbone Service Instance Tag (I-TAG) Tag Control Information (TCI) field of an Ethernet frame as described in . Abstract Data Type: unsigned32 Data Type Semantics: identifier ElementId: 412 References: Status: current Range: The valid range is 0 - 16777215 (i.e., 24 bits).

Description: The value of the 3-bit Backbone Service Instance Priority Code Point (I-PCP) portion of the Backbone Service Instance Tag (I-TAG) Tag Control Information (TCI) field of an Ethernet frame as described in . Abstract Data Type: unsigned8 Data Type Semantics: identifier ElementId: 413 References: Status: current Range: The valid range is 0-7.

Description: The value of the Encapsulated Customer Source Address (C-SA) portion of the Backbone Service Instance Tag (I-TAG) Tag Control Information (TCI) field of an Ethernet frame as described in . Abstract Data Type: macAddress Data Type Semantics: default ElementId: 414 References: Status: current

Description: The value of the Encapsulated Customer Destination Address (C-DA) portion of the Backbone Service Instance Tag (I-TAG) Tag Control Information (TCI) field of an Ethernet frame as described in . Abstract Data Type: macAddress Data Type Semantics: default ElementId: 415 References: Status: current

Description: The definition of this Information Element is identical to the definition of the layer2OctetDeltaCount Information Element, except that it reports a potentially modified value caused by a middlebox function after the packet passed the Observation Point. This Information Element is the layer 2 version of postOctetDeltaCount (ElementId #23). Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter ElementId: 417 References: Status: current Units: octets

Description: The number of layer 2 octets since the previous report (if any) in outgoing multicast packets sent for packets of this Flow by a multicast daemon within the Observation Domain. This property cannot necessarily be observed at the Observation Point but may be retrieved by other means. The number of octets includes layer 2 header(s) and layer 2 payload. This Information Element is the layer 2 version of postMCastOctetDeltaCount (ElementId #20). Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter ElementId: 418 References: Status: current Units: octets

Description: The definition of this Information Element is identical to the definition of the layer2OctetTotalCount Information Element, except that it reports a potentially modified value caused by a middlebox function after the packet passed the Observation Point. This Information Element is the layer 2 version of postOctetTotalCount (ElementId #171). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 420 References: Status: current Units: octets

Description: The total number of layer 2 octets in outgoing multicast packets sent for packets of this Flow by a multicast daemon in the Observation Domain since the Metering Process (re-)initialization. This property cannot necessarily be observed at the Observation Point but may be retrieved by other means. The number of octets includes layer 2 header(s) and layer 2 payload. This Information Element is the layer 2 version of postMCastOctetTotalCount (ElementId #175). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 421 References: Status: current Units: octets

Description: Layer 2 length of the smallest packet observed for this Flow. The packet length includes the length of the layer 2 header(s) and the length of the layer 2 payload. This Information Element is the layer 2 version of minimumIpTotalLength (ElementId #25). Abstract Data Type: unsigned64 ElementId: 422 References: Status: current Units: octets

Description: Layer 2 length of the largest packet observed for this Flow. The packet length includes the length of the layer 2 header(s) and the length of the layer 2 payload. This Information Element is the layer 2 version of maximumIpTotalLength (ElementId #26). Abstract Data Type: unsigned64 ElementId: 423 References: Status: current Units: octets

Description: The number of layer 2 octets since the previous report (if any) in packets of this Flow dropped by packet treatment. The number of octets includes layer 2 header(s) and layer 2 payload. This Information Element is the layer 2 version of droppedOctetDeltaCount (ElementId #132). Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter ElementId: 424 References: Status: current Units: octets

Description: The total number of octets in observed layer 2 packets (including the layer 2 header) that were dropped by packet treatment since the (re-)initialization of the Metering Process. This Information Element is the layer 2 version of droppedOctetTotalCount (ElementId #134). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 425 References: Status: current Units: octets

Description: The total number of octets in observed layer 2 packets (including the layer 2 header) that the Metering Process did not process since the (re-)initialization of the Metering Process. This Information Element is the layer 2 version of ignoredOctetTotalCount (ElementId #165). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 426 References: Status: current Units: octets

Description: The total number of octets in observed layer 2 packets (including the layer 2 header) that the Metering Process did not process since the (re-)initialization of the Metering Process. This Information Element is the layer 2 version of notSentOctetTotalCount (ElementId #168). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 427 References: Status: current Units: octets

Description: The sum of the squared numbers of layer 2 octets per incoming packet since the previous report (if any) for this Flow at the Observation Point. The number of octets includes layer 2 header(s) and layer 2 payload. This Information Element is the layer 2 version of octetDeltaSumOfSquares (ElementId #198). Abstract Data Type: unsigned64 Data Type Semantics: deltaCounter ElementId: 428 References: Status: current Units: octets

Description: The total sum of the squared numbers of layer 2 octets in incoming packets for this Flow at the Observation Point since the Metering Process (re-)initialization for this Observation Point. The number of octets includes layer 2 header(s) and layer 2 payload. This Information Element is the layer 2 version of octetTotalSumOfSquares (ElementId #199). Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 429 References: Status: current Units: octets

The new Information Elements related to packet section (i.e., sectionOffset and sectionExportedOctets) can be applied to not only dataLinkFrameSection but also to all kinds of packet section (i.e., ipHeaderPacketSection, ipPayloadPacketSection, mplsLabelStackSection, and mplsPayloadPacketSection defined in ). Therefore, existing Information Elements Descriptions should be modified as follows.

This Information Element is defined in . The description has been updated from . Description: This Information Element carries a series of n octets from the IP header of a sampled packet, starting sectionOffset octets into the IP header. However, if no sectionOffset field corresponding to this Information Element is present, then a sectionOffset of zero applies, and the octets MUST be from the start of the IP header. With sufficient length, this element also reports octets from the IP payload. However, full packet capture of arbitrary packet streams is explicitly out of scope per the Security Considerations sections of and . The sectionExportedOctets expresses how much data was exported, while the remainder is padding. When the sectionExportedOctets field corresponding to this Information Element exists, this Information Element MAY have a fixed length and MAY be padded, or it MAY have a variable length. When the sectionExportedOctets field corresponding to this Information Element does not exist, this Information Element SHOULD have a variable length and MUST NOT be padded. In this case, the size of the exported section may be constrained due to limitations in the IPFIX protocol. Abstract Data Type: octetArray ElementId: 313 References: Status: current

This Information Element is defined in . The description is updated from . Description: This Information Element carries a series of n octets from the IP payload of a sampled packet, starting sectionOffset octets into the IP payload. However, if no sectionOffset field corresponding to this Information Element is present, then a sectionOffset of zero applies, and the octets MUST be from the start of the IP payload. The IPv4 payload is that part of the packet that follows the IPv4 header and any options, which refers to as "data" or "data octets". For example, see the examples in , Appendix A. The IPv6 payload is the rest of the packet following the 40-octet IPv6 header. Note that any extension headers present are considered part of the payload. See for the IPv6 specification. The sectionExportedOctets expresses how much data was observed, while the remainder is padding. When the sectionExportedOctets field corresponding to this Information Element exists, this Information Element MAY have a fixed length and MAY be padded, or it MAY have a variable length. When the sectionExportedOctets field corresponding to this Information Element does not exist, this Information Element SHOULD have a variable length and MUST NOT be padded. In this case, the size of the exported section may be constrained due to limitations in the IPFIX protocol. Abstract Data Type: octetArray ElementId: 314 References: Status: current

This Information Element is defined in . The description is updated from . Description: This Information Element carries a series of n octets from the MPLS label stack of a sampled packet, starting sectionOffset octets into the MPLS label stack. However, if no sectionOffset field corresponding to this Information Element is present, then a sectionOffset of zero applies, and the octets MUST be from the head of the MPLS label stack. With sufficient length, this element also reports octets from the MPLS payload. However, full packet capture of arbitrary packet streams is explicitly out of scope per the Security Considerations sections of and . See for the specification of MPLS packets. See for the specification of the MPLS label stack. The sectionExportedOctets expresses how much data was observed, while the remainder is padding. When the sectionExportedOctets field corresponding to this Information Element exists, this Information Element MAY have a fixed length and MAY be padded, or it MAY have a variable length. When the sectionExportedOctets field corresponding to this Information Element does not exist, this Information Element SHOULD have a variable length and MUST NOT be padded. In this case, the size of the exported section may be constrained due to limitations in the IPFIX protocol. Abstract Data Type: octetArray ElementId: 316 References: Status: current

This Information Element is defined in . The description is updated from . Description: The mplsPayloadPacketSection carries a series of n octets from the MPLS payload of a sampled packet, starting sectionOffset octets into the MPLS payload, as it is data that follows immediately after the MPLS label stack. However, if no sectionOffset field corresponding to this Information Element is present, then a sectionOffset of zero applies, and the octets MUST be from the start of the MPLS payload. See for the specification of MPLS packets. See for the specification of the MPLS label stack. The sectionExportedOctets expresses how much data was observed, while the remainder is padding. When the sectionExportedOctets field corresponding to this Information Element exists, this Information Element MAY have a fixed length and MAY be padded, or it MAY have a variable length. When the sectionExportedOctets field corresponding to this Information Element does not exist, this Information Element SHOULD have a variable length and MUST NOT be padded. In this case, the size of the exported section may be constrained due to limitations in the IPFIX protocol. Abstract Data Type: octetArray ElementId: 317 References: Status: current

The traffic measurement using IPFIX and PSAMP for a Provider Backbone Bridged Network requires the Information Elements related to Backbone Service Instance Tag (I-TAG) and Backbone VLAN Tag (B-TAG). The set of Information Elements related to I-TAG is added in , because I-TAG structure and semantics are different from that of Service VLAN Tag (S-TAG) and Customer VLAN Tag (C-TAG). The set of Information Elements related to B-TAG reuses the existing Information Elements, because B-TAG structure and semantics are identical to that of C-TAG and S-TAG. This section modifies existing descriptions and references related to C-TAG and S-TAG as follows.

Description: The value of the 12-bit VLAN Identifier portion of the Tag Control Information field of an Ethernet frame. The structure and semantics within the Tag Control Information field are defined in . In Provider Bridged Networks, it represents the Service VLAN identifier in the Service VLAN Tag (S-TAG) Tag Control Information (TCI) field or the Customer VLAN identifier in the Customer VLAN Tag (C-TAG) Tag Control Information (TCI) field as described in . In Provider Backbone Bridged Networks, it represents the Backbone VLAN identifier in the Backbone VLAN Tag (B-TAG) Tag Control Information (TCI) field as described in . In a virtual link between a host system and EVB bridge, it represents the Service VLAN identifier indicating S-channel as described in . In the case of a multi-tagged frame, it represents the outer tag's VLAN identifier, except for I-TAG. Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: 243 Status: current References:

Description: The value of the 3-bit User Priority portion of the Tag Control Information field of an Ethernet frame. The structure and semantics within the Tag Control Information field are defined in . In the case of a multi-tagged frame, it represents the 3-bit Priority Code Point (PCP) portion of the outer tag's Tag Control Information (TCI) field as described in , except for I-TAG. Abstract Data Type: unsigned8 Data Type Semantics: identifier ElementId: 244 Status: current References:

Description: The value represents the Customer VLAN identifier in the Customer VLAN Tag (C-TAG) Tag Control Information (TCI) field as described in . Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: 245 Status: current References:

Description: The value represents the 3-bit Priority Code Point (PCP) portion of the Customer VLAN Tag (C-TAG) Tag Control Information (TCI) field as described in . Abstract Data Type: unsigned8 Data Type Semantics: identifier ElementId: 246 Status: current References:

The following figures show a summary of various Ethernet header fields and the Informational Elements that would be used to represent each of the fields.

<-- 6 --> <-- 4 --> <---- 2 ----> +---------+---------+---------+-------------+ | | | | | | C-DA | C-SA | C-TAG | Length/Type | | a | b | c | d | +---------+---------+---------+-------------+ a.(Information Element) destinationMacAddress (80) b.(Information Element) sourceMacAddress (56) c.(Information Elements) dot1qVlanId (243), dot1qPriority (244) d.(Information Element) ethernetType (256) ]]>

<-- 6 --> <-- 4 --> <-- 4 --> <---- 2 ----> +---------+---------+---------+---------+-------------+ | | | | | | | C-DA | C-SA | S-TAG | C-TAG | Length/Type | | a | b | c | d | e | +---------+---------+---------+---------+-------------+ a.(Information Element) destinationMacAddress (80) b.(Information Element) sourceMacAddress (56) c.(Information Elements) dot1qVlanId (243), dot1qPriority (244) d.(Information Elements) dot1qCustomerVlanId (245), dot1qCustomerPriority (246) e.(Information Element) ethernetType (256) ]]>

<-- 6 --> <-- 4 --> <--- 16 ---> <-- 4 --> <---- 2 ----> +---------+---------+---------+------------+---------+-------------+ | | | | | | | | B-DA | B-SA | B-TAG | I-TAG | C-TAG | Length/Type | | a | b | c | d | e | f | +---------+---------+---------+------------+---------+-------------+ a.(Information Element) destinationMacAddress (80) b.(Information Element) sourceMacAddress (56) c.(Information Elements) dot1qVlanId (243), dot1qPriority (244) d.(Information Elements) dot1qServiceInstanceTag (411), or a set of dot1qServiceInstanceId (412), dot1qServiceInstancePriority (413), dot1qCustomerSourceMacAddress (414) dot1qCustomerDestinationMacAddress (415), e.(Information Elements) dot1qCustomerVlanId (245), dot1qCustomerPriority (246) f.(Information Element) ethernetType (256) ]]>

Reporting more granular data may increase the risk of DoS attacks against a Collector. Protection against DoS attacks is discussed in Section 11.4 of . The recommendations in this document do not otherwise introduce any additional security issues beyond those already mentioned in and .

Existing IPFIX Information Elements have been modified as indicated in Sections , , and . Per Section 5.2 of , for each of these changes, [RFC7133] has been appended to the Requester in IANA's IPFIX registry , the Information Element's Revision number has been incremented by one, and the Information Element's revision Date column has been updated. New IPFIX Information Elements have been allocated as shown in .

Thanks to Brian Trammell and the IPFIX working group participants who contributed to mailing-list discussions throughout the development of this document. Special thanks to Pat Thaler for her help with the IEEE 802 aspects of this work.

&rfc0791; &rfc2119; &rfc2460; &rfc3031; &rfc3032; &rfc7011; &rfc5477; &rfc6313; IEEE IEEE IEEE IEEE IEEE &rfc7012; &rfc7013; &rfc2804; IEEE International Organization for Standardization IANA

Note: The frame format in Figure A-7 is identical to the format in Figure A-3.

Note: The frame format in Figure A-8 is identical to the format in Figure A-4.