RFC 9487
Export of Segment Routing over IPv6 Information in IP Flow Information Export (IPFIX)
Pages: ~23
IETF/ops/opsawg/draft-ietf-opsawg-ipfix-srv6-srh-14
Proposed Standard
Export of Segment Routing over IPv6 Information in IP Flow Information Export (IPFIX)
Abstract
This document introduces new IP Flow Information Export (IPFIX) Information Elements (IEs) to identify a set of information related to Segment Routing over IPv6 (SRv6) such as data contained in a Segment Routing Header (SRH), the SRv6 control plane, and the SRv6 Endpoint behavior that traffic is being forwarded with.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc9487 .
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info ) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.
Table of Contents
- 1. Introduction
- 2. Terminology
- 3. New IPFIX IPv6 SRH Information Elements
- 4. Sample Use Cases
-
5. IANA Considerations
-
5.1. IPFIX Information Elements Registry
- 5.1.1. srhFlagsIPv6
- 5.1.2. srhTagIPv6
- 5.1.3. srhSegmentIPv6
- 5.1.4. srhActiveSegmentIPv6
- 5.1.5. srhSegmentIPv6BasicList
- 5.1.6. srhSegmentIPv6ListSection
- 5.1.7. srhSegmentsIPv6Left
- 5.1.8. srhIPv6Section
- 5.1.9. srhIPv6ActiveSegmentType
- 5.1.10. srhSegmentIPv6LocatorLength
- 5.1.11. srhSegmentIPv6EndpointBehavior
- 5.2. New IPFIX IPv6 SRH Segment Type (Value 500) Subregistry
-
5.1. IPFIX Information Elements Registry
- 6. Operational Considerations
- 7. Security Considerations
- 8. References
- Appendix A. IPFIX Encoding Examples
- Acknowledgements
- Authors' Addresses
1. Introduction
A dedicated Routing Extension Header, called "Segment Routing Header (SRH)", is defined in [RFC 8754] for use of Segment Routing over IPv6 (SRv6) data plane.
Also, three routing protocol extensions, [OSPFV3-SRV6-EXT], [RFC 9352], and [RFC 8669]; the [PCEP-SRV6-EXT]; and the [RFC 9256] are defined to propagate Segment Identifiers (SIDs).
SRv6 Segment Endpoint behaviors describe how packets should be processed by SRv6 Segment Endpoint Nodes. Such behaviors are defined in [RFC 8986].
This document specifies eleven new IPFIX Information Elements (IEs) and one new subregistry within the "IPFIX Information Elements" registry [RFC 7012], for SRv6 purposes.
These IEs are used to export the SRv6 active segment and its control plane protocol, the SRv6 Segment List, the next SRv6 node and its type, and the numbers of SRv6 segments left.
Some examples are provided in Appendix A.
2. Terminology
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 [RFC 2119] [RFC 8174] when, and only when, they appear in all capitals, as shown here.
This document makes use of the terms defined in [RFC 7011], [RFC 8402], and [RFC 8754].
The following terms are used as defined in [RFC 7011]:
- IPFIX
- IPFIX Information Elements
- Template
- Template Record
- Options Template
- Options Template Record
- Data Record
- Data Set
- Segment Routing (SR)
- Segment
- Segment List
- Active Segment
- Segment Identifier (SID)
- SRv6
- SRv6 SID
- Segment Routing Header (SRH)
- SR Source Node
- Transit Node
- SR Segment Endpoint Node
- Reduced SRH
- Segments Left
- Last Entry
3. New IPFIX IPv6 SRH Information Elements
This section specifies the new IPFIX IPv6 SRH IEs.
- srhFlagsIPv6
- The 8-bit Flags field defined in the SRH (Section 2 of RFC 8754).
- srhTagIPv6
- The 16-bit Tag field defined in the SRH (Section 2 of RFC 8754). A tag is used to mark a packet as part of a class or group of packets sharing the same set of properties.
- srhSegmentIPv6
- The 128-bit IPv6 address that represents an SRv6 segment.
- srhActiveSegmentIPv6
- The 128-bit IPv6 address that represents the active SRv6 segment.
- srhSegmentIPv6BasicList
- The ordered basicList [RFC 6313] of zero or more 128-bit IPv6 addresses in the SRH that represents the SRv6 Segment List. As specified in Section 2 of RFC 8754, the Segment List is encoded starting from the last segment of the SR Policy. That is, the first element of the Segment List (Segment List[0]) contains the last segment of the SR Policy, the second element contains the penultimate segment of the SR Policy, and so on.
- srhSegmentIPv6ListSection
- The SRH Segment List as defined in Section 2 of RFC 8754 as a series of octets in IPFIX.
- srhSegmentsIPv6Left
- The 8-bit unsigned integer that defines the number of segments remaining to reach the end of the Segment List from the SRH, as specified by the "Segments Left" field in Section 4.4 of RFC 8200 and as mentioned in the SRH part of Section 2 of RFC 8754.
- srhIPv6Section
- The SRH and its TLVs as specified in Section 2 of RFC 8754 as a series of octets in IPFIX.
- srhIPv6ActiveSegmentType
- The designator of the routing protocol or PCEP extension where the active SRv6 segment has been learned from.
- srhSegmentIPv6LocatorLength
- The length of the SRH segment IPv6 locator specified as the number of significant bits. Together with srhSegmentIPv6, it enables the calculation of the SRv6 Locator.
- srhSegmentIPv6EndpointBehavior
- The 16-bit unsigned integer that represents an SRv6 Endpoint behavior as per Section 4 of RFC 8986.
4. Sample Use Cases
The IPFIX IEs srhSegmentIPv6BasicList (496) or alternatively srhSegmentIPv6ListSection (497), srhActiveSegmentIPv6 (495), srhSegmentsIPv6Left (498), srhIPv6ActiveSegmentType (500), and forwardingStatus (89) [RFC 7270] [IANA-IPFIX] as well as some existing counter information [IANA-IPFIX] provide answers to the following questions (amongst others):
- How many packets steered with an SR policy are forwarded or dropped using SRv6 in a network?
- If dropped, for which reasons?
- What is the current active segment and its associated control plane protocol?
- What is the SRv6 Segment List?
- What is the next SRv6 node and its type?
- How many SRv6 segments are left?
5. IANA Considerations
5.1. IPFIX Information Elements Registry
IANA has added the following new IEs to the "IPFIX Information Elements" registry [RFC 7012] at [IANA-IPFIX]:
Table 1: IPFIX Information Elements Registry
| ElementID | Name |
|---|---|
| 492 | srhFlagsIPv6 |
| 493 | srhTagIPv6 |
| 494 | srhSegmentIPv6 |
| 495 | srhActiveSegmentIPv6 |
| 496 | srhSegmentIPv6BasicList |
| 497 | srhSegmentIPv6ListSection |
| 498 | srhSegmentsIPv6Left |
| 499 | srhIPv6Section |
| 500 | srhIPv6ActiveSegmentType |
| 501 | srhSegmentIPv6LocatorLength |
| 502 | srhSegmentIPv6EndpointBehavior |
5.1.1. srhFlagsIPv6
- ElementID:
- 492
- Name:
- srhFlagsIPv6
- Abstract Data Type:
- unsigned8
- Data Type Semantics:
- flags
- Description:
- The 8-bit Flags field defined in the SRH (Section 2 of RFC 8754). Assigned flags and their meanings are provided in the "Segment Routing Header Flags" IANA registry.
- Additional Information:
-
See the assignments in the "Segment Routing Header Flags" registry at <https://
www.iana.org/ >. See also [RFC 8754] for the SRH specification.assignments/ ipv6-parameters - Reference:
- RFC 9487
5.1.2. srhTagIPv6
- ElementID:
- 493
- Name:
- srhTagIPv6
- Abstract Data Type:
- unsigned16
- Data Type Semantics:
- identifier
- Description:
- The 16-bit Tag field defined in the SRH (Section 2 of RFC 8754). A tag is used to mark a packet as part of a class or group of packets sharing the same set of properties.
- Additional Information:
- See Section 2 of RFC 8754 for more details about the Tag.
- Reference:
- RFC 9487
5.1.3. srhSegmentIPv6
- ElementID:
- 494
- Name:
- srhSegmentIPv6
- Abstract Data Type:
- ipv6Address
- Data Type Semantics:
- default
- Description:
- The 128-bit IPv6 address that represents an SRv6 segment.
- Additional Information:
- Specified in Section 1 of RFC 8402 and mentioned in "Segment List" in Section 2 of RFC 8754.
- Reference:
- RFC 9487
5.1.4. srhActiveSegmentIPv6
5.1.5. srhSegmentIPv6BasicList
- ElementID:
- 496
- Name:
- srhSegmentIPv6BasicList
- Abstract Data Type:
- basicList
- Data Type Semantics:
- list
- Description:
- The ordered basicList [RFC 6313] of zero or more 128-bit IPv6 addresses in the SRH that represents the SRv6 Segment List. As specified in Section 2 of RFC 8754, the Segment List is encoded starting from the last segment of the SR Policy. That is, the first element of the Segment List (Segment List[0]) contains the last segment of the SR Policy, the second element contains the penultimate segment of the SR Policy, and so on.
- Additional Information:
- See Section 2 of RFC 8754 for more details about the SRv6 Segment List.
- Reference:
- RFC 9487
5.1.6. srhSegmentIPv6ListSection
- ElementID:
- 497
- Name:
- srhSegmentIPv6ListSection
- Abstract Data Type:
- octetArray
- Data Type Semantics:
- default
- Description:
- The SRv6 Segment List as defined in Section 2 of RFC 8754 as a series of octets in IPFIX.
- Additional Information:
- See Section 2 of RFC 8754 for more details about the SRv6 Segment List.
- Reference:
- RFC 9487
5.1.7. srhSegmentsIPv6Left
- ElementID:
- 498
- Name:
- srhSegmentsIPv6Left
- Abstract Data Type:
- unsigned8
- Data Type Semantics:
- quantity
- Description:
- The 8-bit unsigned integer defining the number of segments remaining to reach the end of the Segment List from the SRH.
- Additional Information:
- Specified by the "Segments Left" field in Section 4.4 of RFC 8200 and mentioned in Section 2 of RFC 8754.
- Reference:
- RFC 9487
5.1.8. srhIPv6Section
- ElementID:
- 499
- Name:
- srhIPv6Section
- Abstract Data Type:
- octetArray
- Data Type Semantics:
- default
- Description:
- The SRH and its TLVs as defined in Section 2 of RFC 8754 as a series of octets in IPFIX.
- Additional Information:
- See Section 2 of RFC 8754 for more details about the structure of an SRH.
- Reference:
- RFC 9487
5.1.9. srhIPv6ActiveSegmentType
- ElementID:
- 500
- Name:
- srhIPv6ActiveSegmentType
- Abstract Data Type:
- unsigned8
- Data Type Semantics:
- identifier
- Description:
- The designator of the routing protocol or PCEP extension where the active SRv6 segment has been learned from. Values for this Information Element are listed in the "IPFIX IPv6 SRH Segment Type (Value 500)" subregistry.
- Additional Information:
-
See the assigned types in the "IPFIX IPv6 SRH Segment (Value 500)" registry at <https://
www.iana.org/ >.assignments/ ipfix - Reference:
- RFC 9487
5.1.10. srhSegmentIPv6LocatorLength
- ElementID:
- 501
- Name:
- srhSegmentIPv6LocatorLength
- Data Type Semantics:
- default
- Description:
- The length of the SRH segment IPv6 locator specified as the number of significant bits. Together with srhSegmentIPv6, it enables the calculation of the SRv6 Locator.
- Additional Information:
- See Section 3.1 of RFC 8986 for more details about the SID format.
- Reference:
- RFC 9487
5.1.11. srhSegmentIPv6EndpointBehavior
- ElementID:
- 502
- Name:
- srhSegmentIPv6EndpointBehavior
- Abstract Data Type:
- unsigned16
- Data Type Semantics:
- identifier
- Description:
- The 16-bit unsigned integer that represents an SRv6 Endpoint behavior as per Section 4 of RFC 8986. Assigned values and their meanings are provided in the "SRv6 Endpoint Behaviors" registry.
- Additional Information:
-
See the assigned behaviors in the "SRv6 Endpoint Behaviors" registry at <https://
www.iana.org/ >. See Section 4 of RFC 8986 for more details about the processing of endpoint behaviors.assignments/ segment-routing - Reference:
- RFC 9487
5.2. New IPFIX IPv6 SRH Segment Type (Value 500) Subregistry
IANA has created a new subregistry called "IPFIX IPv6 SRH Segment Type (Value 500)" under the "IPFIX Information Elements" registry [RFC 7012] at [IANA-IPFIX].
The allocation policy of this new subregistry is Expert Review (Section 4.5 of RFC 8126).
The designated experts for this registry should be familiar with SRH. The guidelines that are being followed by the designated experts for the "IPFIX Information Elements" registry should be followed for this subregistry. In particular, 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 IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.
Initial values in the registry are defined in Table 2.
Table 2: IPFIX IPv6 SRH Segment Type (Value 500) Subregistry
| Value | Description | Reference |
|---|---|---|
| 0 | Unknown | RFC 9487 |
| 1 | Segment Routing Policy | RFC 9487, [RFC 9256] |
| 2 | Path Computation Element | RFC 9487, [PCEP-SRV6-EXT] |
| 3 | OSPFv3 Segment Routing | RFC 9487, [OSPFV3-SRV6-EXT] |
| 4 | IS-IS Segment Routing | RFC 9487, [RFC 9352] |
| 5 | BGP Segment Routing Prefix-SID | RFC 9487, [RFC 8669] |
6. Operational Considerations
6.1. SRv6 Segment List
The zero or more 128-bit IPv6 addresses in the SRH [RFC 8754] can be exported in two different ways, with two different IPFIX IEs:
- srhSegmentIPv6BasicList
- srhSegmentIPv6ListSection
6.2. Compressed SRv6 Segment List Decomposition
The SRv6 Segment List in the IPFIX IEs srhSegmentIPv6BasicList, srhSegmentIPv6ListSection, and destinationIPv6Address could contain compressed-SID containers as described in [SRV6-SRH-COM]. The SR Endpoint Flavors, as described in Section 4 of [SRV6-SRH-COM], define new flavors for SID Endpoint behaviors and determine wherever the Segment List encoding is compressed, along with the flavor. The SID Locator, as described in Section 3.1 of RFC 8986, determines the common most significant bits. By using described information from srhSegmentIPv6EndpointBehavior and srhSegmentIPv6LocatorLength, the compressed-SID containers can be decoded at the data collection.
7. Security Considerations
There are no additional security considerations regarding allocation of these new IPFIX IEs compared to [RFC 7012].
The IEs described in this document export provider plane data metrics on how packets are being forwarded within an SRv6 network. Applications and operators using the IEs described in this document must evaluate the sensitivity of this information in their implementation context and apply the data-at-rest storage guidance in Section 11.8 of RFC 7011 as appropriate.
8. References
8.1. Normative References
- [RFC2119]
-
S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/ >.rfc2119 - [RFC6313]
-
B. Claise, G. Dhandapani, P. Aitken, and S. Yates, "Export of Structured Data in IP Flow Information Export (IPFIX)", RFC 6313, DOI 10.17487/RFC6313, July 2011,
<https://www.rfc-editor.org/info/ >.rfc6313 - [RFC7011]
-
B. Claise, B. Trammell, and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013,
<https://www.rfc-editor.org/info/ >.rfc7011 - [RFC7012]
-
B. Claise, and B. Trammell, "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, DOI 10.17487/RFC7012, September 2013,
<https://www.rfc-editor.org/info/ >.rfc7012 - [RFC8126]
-
M. Cotton, B. Leiba, and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/ >.rfc8126 - [RFC8174]
-
B. Leiba, "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017,
<https://www.rfc-editor.org/info/ >.rfc8174 - [RFC8200]
-
S. Deering, and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/ >.rfc8200 - [RFC8754]
-
C. Filsfils, D. Dukes, S. Previdi, J. Leddy, S. Matsushima, and D. Voyer, "IPv6 Segment Routing Header (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/ >.rfc8754
8.2. Informative References
- [IANA-IPFIX]
-
IANA, "IP Flow Information Export (IPFIX) Entities",
<https://www.iana.org/assignments/ >.ipfix -
[OSPFV3-SRV6-EXT]
-
Cisco Systems, Z. Li, Z. Hu, K. Talaulikar, and P. Psenak, "OSPFv3 Extensions for SRv6", Internet-Draft draft-ietf-lsr-ospfv3-srv6-extensions-15, June 2023,
<https://datatracker.ietf.org/doc/ >.html/ draft-ietf-lsr-ospfv3-srv6-extensions-15 -
[PCEP-SRV6-EXT]
-
China Telecom, C. Li, P. Kaladharan, S. Sivabalan, M. Koldychev, and Y. Zhu, "Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing leveraging the IPv6 dataplane", Internet-Draft draft-ietf-pce-segment-routing-ipv6-20, September 2023,
<https://datatracker.ietf.org/doc/ >.html/ draft-ietf-pce-segment-routing-ipv6-20 - [RFC7270]
-
A. Yourtchenko, P. Aitken, and B. Claise, "Cisco-Specific Information Elements Reused in IP Flow Information Export (IPFIX)", RFC 7270, DOI 10.17487/RFC7270, June 2014,
<https://www.rfc-editor.org/info/ >.rfc7270 - [RFC8402]
-
C. Filsfils, S. Previdi, L. Ginsberg, B. Decraene, S. Litkowski, and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018,
<https://www.rfc-editor.org/info/ >.rfc8402 - [RFC8669]
-
S. Previdi, C. Filsfils, A. Lindem, A. Sreekantiah, and H. Gredler, "Segment Routing Prefix Segment Identifier Extensions for BGP", RFC 8669, DOI 10.17487/RFC8669, December 2019,
<https://www.rfc-editor.org/info/ >.rfc8669 - [RFC8986]
-
C. Filsfils, P. Camarillo, J. Leddy, D. Voyer, S. Matsushima, and Z. Li, "Segment Routing over IPv6 (SRv6) Network Programming", RFC 8986, DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/ >.rfc8986 - [RFC9256]
-
C. Filsfils, K. Talaulikar, D. Voyer, A. Bogdanov, and P. Mattes, "Segment Routing Policy Architecture", RFC 9256, DOI 10.17487/RFC9256, July 2022,
<https://www.rfc-editor.org/info/ >.rfc9256 - [RFC9352]
-
P. Psenak, C. Filsfils, A. Bashandy, B. Decraene, and Z. Hu, "IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane", RFC 9352, DOI 10.17487/RFC9352, February 2023,
<https://www.rfc-editor.org/info/ >.rfc9352 -
[SRV6-SRH-COM]
-
Cisco Systems, Inc., W. Cheng, C. Filsfils, Z. Li, B. Decraene, and F. Clad, "Compressed SRv6 Segment List Encoding", Internet-Draft draft-ietf-spring-srv6-srh-compression-09, October 2023,
<https://datatracker.ietf.org/doc/ >.html/ draft-ietf-spring-srv6-srh-compression-09
Appendix A. IPFIX Encoding Examples
This appendix represents three different encodings for the newly introduced IEs, for the example values in Table 3. The three different encodings use the following IEs, respectively: srhSegmentIPv6BasicList, srhSegmentIPv6ListSection, and srhIPv6Section.
Table 3: Three Observed SRH Headers and Their Associated Routing Protocols
| SRH Nr | SRH Flags | SRH Tag | Active Segment Type | Segment List |
|---|---|---|---|---|
| 1 | 0 | 123 | IS-IS [4] | 2001:db8::1, 2001:db8::2, 2001:db8::3 |
| 2 | 0 | 456 | IS-IS [4] | 2001:db8::4, 2001:db8::5 |
| 3 | 0 | 789 | IS-IS [4] | 2001:db8::6 |
A.1. Three Observed SRH Headers and Their Routing Protocols
A.1.1. Template Record and Data Set with Segment Basic List
With encoding in Figure 1, the examples in Table 3 are represented with the following IEs, where "=>" is used to indicate which IE is mapped to given information:
In this example, the Template ID is 256, which will be used in the Data Record. The field length for srhSegmentIPv6BasicList is 0xFFFF, which means the length of this IE is variable, and the actual length of this IE is indicated by the List Length field in the basicList format as per [RFC 6313].
The data set is represented as follows:
- SRH Flags => srhFlagsIPv6 (492)
- SRH Tag => srhTagIPv6 (493)
- Active Segment Type => srhIPv6ActiveSegmentType (500)
- Segment List => srhSegmentIPv6BasicList (496)
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 2 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 256 | Field Count = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| srhFlagsIPv6 = 492 | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| srhTagIPv6 = 493 | Field Length = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|srhIPv6ActiveSegmentType= 500| Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|srhSegmentIPv6BasicList = 496| Field Length = 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 256 | Length = 136 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhFlagsIPv6 | srhTagIPv6 = 123 |srhIPv6Active | | = 0 | |SegmentType= 4| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 255 | List Length = 53 |semantic= | | | |ordered | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhSegmentIPv6 = 494 | Field Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[0] = 2001:db8::1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[1] = 2001:db8::2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[2] = 2001:db8::3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhFlagsIPv6 | srhTagIPv6 = 456 | srhIPv6Active | | = 0 | | SegmentType= 4| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 255 | List Length = 37 |semantic= | | | |ordered | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhSegmentIPv6 = 494 | Field Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[0] = 2001:db8::4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[1] = 2001:db8::5 (16 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhFlagsIPv6 | srhTagIPv6 = 789 | srhIPv6Active | | = 0 | | SegmentType= 4| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 255 | List Length = 21 |semantic= | | | |ordered | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhSegmentIPv6 = 494 | Field Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List[0] = 2001:db8::6 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A.1.2. Template Record and Data Set with Segment List Section
With encoding in Figure 3, the examples in Table 3 are represented with the following IEs, where "=>" is used to indicate which IE is mapped to given information:
In this example, the Template ID is 257, which will be used in the Data Record. The field length for srhSegmentIPv6ListSection in the Template Record is 0xFFFF, which means that the length of this IE is variable: its actual length is encoded in the Data Set. Note that, with an actual length inferior to 255 in the Data Record example, the length field is encoded in 8 bits (Section 7 of RFC 7011).
The data can be represented as follows:
- SRH Flags => srhFlagsIPv6 (492)
- SRH Tag => srhTagIPv6 (493)
- Active Segment Type => srhIPv6ActiveSegmentType (500)
- Segment List => srhSegmentIPv6ListSection (497)
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 2 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 257 | Field Count = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| srhFlagsIPv6 = 492 | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| srhTagIPv6 = 493 | Field Length = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|srhIPv6ActiveSegmentType= 500| Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|srhSegmentIPv6ListSection=497| Field Length = 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 257 | Length = 116 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhFlagsIPv6 | srhTagIPv6 = 123 | srhIPv6Active | | = 0 | | SegmentType= 4| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length = 48 | 2001:db8::1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 2001:db8::2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 2001:db8::3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | srhFlagsIPv6 | srhTagIPv6 = 456 | | | = 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhIPv6Active | Length = 32 | 2001:db8::4 | | SegmentType= 4| | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 2001:db8::5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... |srhFlagsIPv6=0 | srhTagIPv6 = | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 789 | srhIPv6ActiveSegmentType = 4 | Length = 16 | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::6 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A.1.3. Template Record and Data Set with SRH Section
With encoding in Figure 5, the examples in Table 3 are represented with the following IEs, where "=>" is used to indicate which IE is mapped to given information:
In this example, the Template ID is 258, which will be used in the Data Record. The field length for srhIPv6Section in the Template Record is 0xFFFF, which means that the length of this IE is variable: its actual length is encoded in the Data Set. Note that, with an actual length inferior to 255 in the Data Record example, the length field is encoded in 8 bits (Section 7 of RFC 7011).
The data can be represented as follows:
(*) The Length must be calculated to include the optional Type Length Value objects.
- SRH Flags + SRH Tag + Segment List => srhIPv6Section (499)
- Active Segment Type => srhIPv6ActiveSegmentType (500)
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 2 | Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 258 | Field Count = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|srhIPv6ActiveSegmentType= 500| Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| srhIPv6Section = 499 | Field Length = 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 258 | Length = (*) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhIPv6ActiveSegmentType = 4 | Length = (*) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Next Header | Hdr Ext Len | Routing Type | Segments Left | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Last Entry | Flags | Tag | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Optional Type Length Value objects (variable) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhIPv6ActiveSegmentType = 4 | 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Next Header | Hdr Ext Len | Routing Type | Segments Left | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Last Entry | Flags | Tag | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Optional Type Length Value objects (variable) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhIPv6ActiveSegmentType = 4 | 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Next Header | Hdr Ext Len | Routing Type | Segments Left | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Last Entry | Flags | Tag | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2001:db8::6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Optional Type Length Value objects (variable) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A.2. Options Template Record and Data Set for SRv6 Segment Endpoint Behavior and Locator Length
This appendix provides an SRv6 Endpoint Behavior Options Template example, for the values presented in Table 4. In the Options Template case, the srhActiveSegmentIPv6 IE is a Scope field.
Table 4: Three Observed SRv6 Segment Endpoint Behaviors
In this example, the Template ID is 259, which will be used in the Data Record.
The data set is represented as follows:
(*) The Length must be calculated to include the optional Type Length Value objects.
| Entry Nr | SRH Endpoint IPv6 | SRH Endpoint Behavior | SRH Segment Locator Length |
|---|---|---|---|
| 1 | 2001:db8::1 | End [1] | 48 |
| 2 | 2001:db8::4 | End with NEXT-CSID [43] | 48 |
| 3 | 2001:db8::6 | End.DX6 [16] | 48 |
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 3 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID 259 | Field Count = 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count = 1 |0| srhActiveSegmentIPv6 = 495 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope 1 Field Length = 4 |0|srhSegmentIPv6End.Behav = 502| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 1 |0|srhSegmentIPv6Lo.Length = 501| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SET ID = 259 | Length = 28 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhActiveSegmentIPv6 = 2001:db8::1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |srhSegmentIPv6EndpointBehavior |srhSegmentIPv6LocatorLength= 48| |= End [1] | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhActiveSegmentIPv6 = 2001:db8::4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |srhSegmentIPv6EndpointBehavior |srhSegmentIPv6LocatorLength= 48| |= End with NEXT-CSID [43] | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | srhActiveSegmentIPv6 = 2001:db8::6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |srhSegmentIPv6EndpointBehavior |srhSegmentIPv6LocatorLength= 48| |= End.DX6 [16] | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Acknowledgements
The authors would like to thank Yao Liu, Eduard Vasilenko, Bruno Decraene, Mohamed Boucadair, Kamran Raza, Qin Wu, Jim Guichard, Tero Kivinen, Paul Aitken, Roman Danyliw, John Scudder, Éric Vyncke, Erik Kline, Lars Eggert, and Andrew Alston for their reviews and valuable comments. And thank you to Paolo Lucente and Alex Huang Feng for the implementation and validation.
Authors' Addresses
Thomas Graf
Swisscom
Binzring 17
Zurich 8045
Switzerland
Email: thomas.graf@swisscom.com
Benoit Claise
Huawei
Email: benoit.claise@huawei.com
Pierre Francois
INSA-Lyon
Lyon
France
Email: pierre.francois@insa-lyon.fr
