]> Orange

mohamed.boucadair@orange.com

Huawei

benoit.claise@huawei.com

Operations and Management OPSAWG IPFIX This document specifies new 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. 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 This document specifies new IPFIX Information Elements (IEs) to solve a set of issues encountered with the current specifications of ipv6ExtensionHeaders (for IPv6 Extension Headers (EHs)) and tcpOptions (to export TCP options). More details about these issues are provided in the following sub-sections.

ipv6ExtensionHeaders Issues The specification of ipv6ExtensionHeaders IPFIX IE does not:

• Cover the full EHs range (Section 4 of ).
• Specify how to automatically update the IANA IPFIX registry () when a new value is assigned in .
• Specify the procedure to follow when all bits are exhausted.

tcpOptions Issues Only TCP options having a kind =< 63 can be included in a tcpOptions IPFIX IE. The specification of the tcpOptions IPFIX IE does not describe 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) .

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.

IPv6 Extension Header

ipv6ExtensionHeadersFull Information Element

Name:

ipv6ExtensionHeadersFull

ElementID:

TBD1

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 EH associated with each bit is provided in [NEW_IPFIX_IPv6EH_SUBREGISTRY].

The value should be encoded in fewer octets as per the guidelines in .

Abstract Data Type:

unsigned

Data Type Semantics:

flags

Additional Information:

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

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

Reference:

This-Document

ipv6ExtensionHeaderCount Information Element

Name:

ipv6ExtensionHeaderCount

ElementID:

TBD2

Description:

As per , IPv6 nodes must accept and attempt to process extension headers in occurring any number of times in the same packet. This Information Element echoes the number of occurences of the same EH instance in an IPv6 packet. EH Type values are taken from .

IPFIX reduced-size encoding as per is used as required.

Abstract Data Type:

unsigned64

Data Type Semantics:

identifier

Additional Information:

See the assigned IPv6 extension header types in .

See for the general definition of IPv6 extension headers.

Reference:

This-Document

Information Elements for TCP Options

tcpOptionsFull Information Element This section specifies a new Information Element to cover the full TCP options range.

Name:

tcpOptionsFull

ElementID:

TBD3

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.

The value should be encoded in fewer octets as per the guidelines in .

Abstract Data Type:

unsigned

Data Type Semantics:

flags

Additional Information:

See the assigned TCP option kinds at .

See for the general definition of TCP options.

Reference:

This-Document

New Information Elements for Shared TCP Options ExIDs can be either 2 or 4 bytes in length . Two new IPFIX IEs are defined to accomodate these two lengths without introducing extra complexity in mixing both types in the same IPFIX IE.

tcpSharedOptionExID16 Information Element

Name:

tcpSharedOptionExID16

ElementID:

TBD4

Description:

Observed 2-byte Expermients IDs (ExIDs) in a shared TCP option (Kind=253 or 254). The information is encoded in a set of 16-bit fields. Each 16-bit field carries the observed 2-byte ExID in a shared option.

Abstract Data Type:

octetArray

Data Type Semantics:

identifier

Additional Information:

See assigned 16-bit ExIDs at .

Reference:

This-Document

tcpSharedOptionExID32 Information Element

Name:

tcpSharedOptionExID32

ElementID:

TBD5

Description:

Observed 4-byte Expermients ID (ExIDs) in a shared TCP option (Kind=253 or 254). The information is encoded in a set of 16-bit fields. Each 32-bit field carries the observed 4-byte ExID in a shared option.

Abstract Data Type:

octetArray

Data Type Semantics:

identifier

Additional Information:

See assigned 32-bit ExIDs at .

Reference:

This-Document

Security Considerations IPFIX security considerations are discussed in .

IANA Considerations This document requests IANA to add the following new IPFIX IEs to the IANA IPFIX registry : New IPFIX Information Elements

Value	Name	Reference
TBD1	ipv6ExtensionHeadersFull	of This-Document
TBD2	ipv6ExtensionHeaderCount	of This-Document
TBD3	tcpOptionsFull	of This-Document
TBD4	tcpSharedOptionExID16	of This-Document
TBD5	tcpSharedOptionExID32	of This-Document

Normative References IANA IANA IANA IANA This document specifies version 6 of the Internet Protocol (IPv6). It obsoletes RFC 2460. 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. 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 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. This document specifies the Transmission Control Protocol (TCP). TCP is an important transport-layer protocol in the Internet protocol stack, and it has continuously evolved over decades of use and growth of the Internet. Over this time, a number of changes have been made to TCP as it was specified in RFC 793, though these have only been documented in a piecemeal fashion. This document collects and brings those changes together with the protocol specification from RFC 793. This document obsoletes RFC 793, as well as RFCs 879, 2873, 6093, 6429, 6528, and 6691 that updated parts of RFC 793. It updates RFCs 1011 and 1122, and it should be considered as a replacement for the portions of those documents dealing with TCP requirements. It also updates RFC 5961 by adding a small clarification in reset handling while in the SYN-RECEIVED state. The TCP header control bits from RFC 793 have also been updated based on RFC 3168. 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.

Acknowledgments Thanks to Paul Aitken for the review.