OSPF Link Traffic Engineering (TE) Attribute Reuse
draft-ietf-ospf-te-link-attr-reuse-06
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8920.
|
|
|---|---|---|---|
| Authors | Peter Psenak , Acee Lindem , Les Ginsberg , Wim Henderickx , Jeff Tantsura , Hannes Gredler , John Drake | ||
| Last updated | 2018-11-09 | ||
| Replaces | draft-ppsenak-ospf-te-link-attr-reuse | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 8920 (Proposed Standard) | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-ospf-te-link-attr-reuse-06
LSR Working Group P. Psenak, Ed.
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track A. Lindem
Expires: May 13, 2019 L. Ginsberg
Cisco Systems
W. Henderickx
Nokia
J. Tantsura
Nuage Networks
H. Gredler
RtBrick Inc.
J. Drake
Juniper Networks
November 9, 2018
OSPF Link Traffic Engineering (TE) Attribute Reuse
draft-ietf-ospf-te-link-attr-reuse-06.txt
Abstract
Various link attributes have been defined in OSPF in the context of
the MPLS Traffic Engineering (TE) and GMPLS. Many of these link
attributes can be used for applications other than MPLS Traffic
Engineering or GMPLS. This document defines how to distribute such
attributes in OSPFv2 and OSPFv3 for applications other than MPLS
Traffic Engineering or GMPLS.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 13, 2019.
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Copyright Notice
Copyright (c) 2018 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
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material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 4
2. Link attributes examples . . . . . . . . . . . . . . . . . . 4
3. Advertising Link Attributes . . . . . . . . . . . . . . . . . 4
3.1. OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA . . . . 4
3.2. OSPFv2 Extended Link Opaque LSA and OSPFv3 E-Router-LSA . 5
3.3. Selected Approach . . . . . . . . . . . . . . . . . . . . 6
4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 6
4.1. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 6
4.2. Extended Metrics . . . . . . . . . . . . . . . . . . . . 7
4.3. Traffic Engineering Metric . . . . . . . . . . . . . . . 8
4.4. Administrative Group . . . . . . . . . . . . . . . . . . 8
5. Advertisement of Application Specific Values . . . . . . . . 8
6. Maximum Link Bandwidth . . . . . . . . . . . . . . . . . . . 11
7. Local Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 12
8. Remote Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 12
9. Deployment Considerations . . . . . . . . . . . . . . . . . . 12
10. Attribute Advertisements and Enablement . . . . . . . . . . . 13
11. Backward Compatibility . . . . . . . . . . . . . . . . . . . 14
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12. Security Considerations . . . . . . . . . . . . . . . . . . . 14
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
13.1. OSPFv2 . . . . . . . . . . . . . . . . . . . . . . . . . 14
13.2. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 15
14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
15.1. Normative References . . . . . . . . . . . . . . . . . . 16
15.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
Various link attributes have been defined in OSPFv2 [RFC2328] and
OSPFv3 [RFC5340] in the context of the MPLS traffic engineering and
GMPLS. All these attributes are distributed by OSPFv2 as sub-TLVs of
the Link-TLV advertised in the OSPFv2 TE Opaque LSA [RFC3630]. In
OSPFv3, they are distributed as sub-TLVs of the Link-TLV advertised
in the OSPFv3 Intra-Area-TE-LSA as defined in [RFC5329].
Many of these link attributes are useful outside of traditional MPLS
Traffic Engineering or GMPLS. This brings its own set of problems,
in particular how to distribute these link attributes in OSPFv2 and
OSPFv3 when MPLS TE and GMPLS are not deployed or are deployed in
parallel with other applications that use these link attributes.
[RFC7855] discusses use cases/requirements for SR. Included among
these use cases is SRTE. If both RSVP-TE and SRTE are deployed in a
network, link attribute advertisements can be used by one or both of
these applications. As there is no requirement for the link
attributes advertised on a given link used by SRTE to be identical to
the link attributes advertised on that same link used by RSVP-TE,
there is a clear requirement to indicate independently which link
attribute advertisements are to be used by each application.
As the number of applications which may wish to utilize link
attributes may grow in the future, an additional requirement is that
the extensions defined allow the association of additional
applications to link attributes without altering the format of the
advertisements or introducing new backwards compatibility issues.
Finally, there may still be many cases where a single attribute value
can be shared among multiple applications, so the solution should
minimize advertising duplicate link/attribute when possible.
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1.1. Requirements notation
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 [RFC2119].
2. Link attributes examples
This section lists some of the link attributes originally defined for
MPLS Traffic Engineering that can be used for other applications in
OSPFv2 and OSPFv3. The list doesn", RFC 3339, DOI 10.17487/
RFC3339, July 2002,
<http://www.rfc-editor.org/info/rfc3339>.
[RFC3470] Hollenbeck, S., Rose, M., and L. Masinter,
"Guidelines for the Use of Extensible Markup
Language (XML) within IETF Protocols", BCP 70,
RFC 3470, DOI 10.17487/RFC3470, January 2003,
<http://www.rfc-editor.org/info/rfc3470>.
[RFC3667] Bradner, S., "IETF Rights in Contributions",
RFC 3667, DOI 10.17487/RFC3667, February 2004,
<http://www.rfc-editor.org/info/rfc3667>.
[RFC3966] Schulzrinne, H., "The tel URI for Telephone
Numbers", RFC 3966, DOI 10.17487/RFC3966,
December 2004,
<http://www.rfc-editor.org/info/rfc3966>.
[RFC3978] Bradner, S., "IETF Rights in Contributions",
RFC 3978, DOI 10.17487/RFC3978, March 2005,
<http://www.rfc-editor.org/info/rfc3978>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter,
"Uniform Resource Identifier (URI): Generic Syntax",
STD 66, RFC 3986, DOI 10.17487/RFC3986,
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January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC5741] Daigle, L. and O. Kolkman, "RFC Streams, Headers,
and Boilerplates", RFC 5741, DOI 10.17487/RFC5741,
December 2009,
<http://www.rfc-editor.org/info/rfc5741>.
[RFC6068] Duerst, M., Masinter, L., and J. Zawinski, "The
'mailto' URI Scheme", RFC 6068, DOI 10.17487/
RFC6068, October 2010,
<http://www.rfc-editor.org/info/rfc6068>.
[RFC6266] Reschke, J., "Use of the Content-Disposition Header
Field in the Hypertext Transfer Protocol (HTTP)",
RFC 6266, DOI 10.17487/RFC6266, June 2011,
<http://www.rfc-editor.org/info/rfc6266>.
[RFC6949] Flanagan, H. and N. Brownlee, "RFC Series Format
Requirements and Future Development", RFC 6949,
DOI 10.17487/RFC6949, May 2013,
<http://www.rfc-editor.org/info/rfc6949>.
[RFC7303] Thompson, H. and C. Lilley, "XML Media Types",
RFC 7303, DOI 10.17487/RFC7303, July 2014,
<http://www.rfc-editor.org/info/rfc7303>.
[RFC7322] Heather, H. and S. Ginoza, "RFC Style Guide",
RFC 7322, DOI 10.17487/RFC7322, September 2014,
<http://www.rfc-editor.org/info/rfc7322>.
[RFCPOLICY] RFC Editor, "RFC Editorial Guidelines and
Procedures",
<http://www.rfc-editor.org/policy.html>.
[RNC] Clark, J., "RELAX NG Compact Syntax", OASIS ,
November 2002, <http://www.oasis-open.org/
committees/relax-ng/compact-20021121.html>.
[RNG] ISO/IEC, "Information Technology - Document Schema
Definition Languages (DSDL) - Part 2: Regular-
Grammar-Based Validation - RELAX NG. Second
Edition.", ISO/IEC 19757-2:2008(E), December 2008.
A useful source of RNG-related information is
<http://relaxng.org/>.
[SVGforRFCs] Brownlee, N., "SVG Drawings for RFCs: SVG 1.2 RFC",
Hoffman Expires December 19, 2015 [Page 86]
Internet-Draft The 'XML2RFC' version 3 Vocabulary June 2015
draft-brownlee-svg-rfc (work in progress), 2015.
[TLP2.0] IETF Trust, "Legal Provisions Relating to IETF
Documents", February 2009, <http://trustee.ietf.org/
license-info/IETF-TLP-2.htm>.
[TLP3.0] IETF Trust, "Legal Provisions Relating to IETF
Documents", September 2009, <http://
trustee.ietf.org/license-info/IETF-TLP-3.htm>.
[TLP4.0] IETF Trust, "Legal Provisions Relating to IETF
Documents", December 2009, <http://trustee.ietf.org/
license-info/IETF-TLP-4.htm>.
[UAX24] The Unicode Consortium, "UAX #24: Unicode Script
Property", <http://www.unicode.org/reports/tr24/>.
[UNICODE] The Unicode Consortium, "The Unicode Standard".
For the latest version, see
<http://www.unicode.org/versions/latest/>.
[USASCII] American National Standards Institute, "Coded
Character Set -- 7-bit American Standard Code for
Information Interchange", ANSI X3.4, 1986.
[XInclude] Marsh, J., Orchard, D., and D. Veillard, "XML
Inclusions (XInclude) Version 1.0 (Second Edition)",
W3C Recommendation REC-xinclude-20061115,
November 2006, <http://www.w3.org/TR/xinclude/>.
Latest version available at
<http://www.w3.org/TR/xinclude/>.
[XPOINTER] Grosso, P., Maler, E., Marsh, J., and N. Walsh,
"XPointer Framework", W3C Recommendation REC-xptr-
framework-20030325, March 2003, <http://www.w3.org/
TR/2003/REC-xptr-framework-20030325/>.
Latest version available at
<http://www.w3.org/TR/xptr-framework/>.
Appendix A. Front Page ('Boilerplate') Generation
A.1. The /rfc/@ipr Attribute
This attribute value can take a long list of values, each of which
describes an IPR policy for the document (Section 2.45.5). The
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values are not the result of a grand design, but remain simply for
historic reasons. Of these values, only a few are currently in use;
all others are supported by various tools for backwards compatibility
with old source files.
*Note:* some variations of the boilerplate are selected based on
the document's date; therefore it is important to specify the
"year", "month" and "day" attributes of the <date> element when
archiving the XML source of an Internet-Draft on the day of
submission.
_Disclaimer: THIS ONLY PROVIDES IMPLEMENTATION INFORMATION. IF YOU
NEED LEGAL ADVICE, PLEASE CONTACT A LAWYER._ For further information,
refer to <http://trustee.ietf.org/docs/IETF-Copyright-FAQ.pdf>.
For the current "Status Of This Memo" text, the submissionType
attribute (Section 2.45.12) determines whether a statement about
"Code Components" is inserted (which is the case for the value
"IETF", which is the default). Other values, such as "independent",
suppress this part of the text.
A.1.1. Current Values: '*trust200902'
The name for these values refers to the "IETF TRUST Legal Provisions
Relating to IETF Documents", sometimes simply called the "TLP", which
went into effect on February 15, 2009 ([TLP2.0]). Updates to this
document were published on September 12, 2009 ([TLP3.0]) and on
December 28, 2009 ([TLP4.0]), modifying the license for code
components (see <http://trustee.ietf.org/license-info/> for further
information). The actual text is located in Section 6 ("Text To Be
Included in IETF Documents") of these documents.
The prep tool automatically produces the "correct" text depending on
the document's date information (see above):
+----------+--------------------------------+
| TLP | starting with publication date |
+----------+--------------------------------+
| [TLP3.0] | 2009-11-01 |
| [TLP4.0] | 2010-04-01 |
+----------+--------------------------------+
A.1.1.1. trust200902
This value should be used unless one of the more specific
'*trust200902' values is a better fit. It produces the text in
Sections 6.a and 6.b of the TLP.
Hoffman Expires December 19, 2015 [Page 88]
#x27;t necessarily contain all the
required attributes.
1. Remote Interface IP address [RFC3630] - OSPFv2 currently cannot
distinguish between parallel links between two OSPFv2 routers.
As a result, the two-way connectivity check performed during SPF
may succeed when the two routers disagree on which of the links
to use for data traffic.
2. Link Local/Remote Identifiers - [RFC4203] - Used for the two-way
connectivity check for parallel unnumbered links. Also used for
identifying adjacencies for unnumbered links in Segment Routing
traffic engineering.
3. Shared Risk Link Group (SRLG) [RFC4203] - In IPFRR, the SRLG is
used to compute diverse backup paths [RFC5714].
4. Unidirectional Link Delay/Loss Metrics [RFC7471] - Could be used
for the shortest path first (SPF) computation using alternate
metrics within an OSPF area.
3. Advertising Link Attributes
This section outlines possible approaches for advertising link
attributes originally defined for MPLS Traffic Engineering or GMPLS
when they are used for other applications.
3.1. OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA
One approach for advertising link attributes is to continue to use
the OSPFv2 TE Opaque LSA [RFC3630] or the OSPFv3 Intra-Area-TE-LSA
[RFC5329]. There are several problems with this approach:
1. Whenever the link is advertised in an OSPFv2 TE Opaque LSA or in
an OSPFv3 Intra-Area-TE-LSA, the link becomes a part of the TE
topology, which may not match IP routed topology. By making the
link part of the TE topology, remote nodes may mistakenly believe
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that the link is available for MPLS TE or GMPLS, when, in fact,
MPLS is not enabled on the link.
2. The OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA advertise
link attributes that are not used or required by MPLS TE or
GMPLS. There is no mechanism in these TE LSAs to indicate which
of the link attributes are passed to the MPLS TE application and
which are used by other applications including OSPF itself.
3. Link attributes used for non-TE applications are partitioned
across multiple LSAs - the TE Opaque LSA and the Extended Link
Opaque LSA in OSPFv2 and the OSPFv3 Intra-Area-TE-LSA and OSPFv3
Extended LSA Router-Link TLV [RFC8362] in OSPFv3. This
partitioning will require implementations to lookup multiple LSAs
to extract link attributes for a single link, bringing needless
complexity to OSPF implementations.
The advantage of this approach is that there is no additional
standardization requirement to advertise the TE/GMPL attributes for
other applications. Additionally, link attributes are only
advertised once when both OSPF TE and other applications are deployed
on the same link. This is not expected to be a common deployment
scenario.
3.2. OSPFv2 Extended Link Opaque LSA and OSPFv3 E-Router-LSA
An alternative approach for advertising link attributes is to use
Extended Link Opaque LSAs as defined in [RFC7684] for OSPFv2 and
Extended Router-LSAs [RFC8362] for OSPFv3. These LSAs were defined
as a generic containers for distribution of the extended link
attributes. There are several advantages in using them:
1. Advertisement of the link attributes does not make the link part
of the TE topology. It avoids any conflicts and is fully
compatible with the [RFC3630] and [RFC5329].
2. The OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA remains
truly opaque to OSPFv2 and OSPFv3 as originally defined in
[RFC3630] and [RFC5329] respectively. Their contents are not
inspected by OSPF, that act as a pure transport.
3. There is clear distinction between link attributes used by TE and
link attributes used by other OSPFv2 or OSPFv3 applications.
4. All link attributes that are used by other applications are
advertised in a single LSA, the Extended Link Opaque LSA in
OSPFv2 or the OSPFv3 E-Router-LSA [RFC8362] in OSPFv3.
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The disadvantage of this approach is that in rare cases, the same
link attribute is advertised in both the TE Opaque and Extended Link
Attribute LSAs in OSPFv2 or the Intra-Area-TE-LSA and E-Router-LSA in
OSPFv3. Additionally, there will be additional standardization
effort. However, this could also be viewed as an advantage as the
non-TE use cases for the TE link attributes are documented and
validated by the LSR working group.
3.3. Selected Approach
It is RECOMMENDED to use the Extended Link Opaque LSA [RFC7684] and
E-Router-LSA [RFC8362] to advertise any link attributes used for non-
TE applications in OSPFv2 or OSPFv3 respectively, including those
that have been originally defined for TE applications.
It is also RECOMMENDED that TE link attributes used for RSVP-TE/GMPLS
continue to use OSPFv2 TE Opaque LSA [RFC3630] and OSPFv3 Intra-Area-
TE-LSA [RFC5329].
It is also RECOMMENDED to keep the format of the link attribute TLVs
that have been defined for TE applications unchanged even when they
are used for non-TE applications.
Finally, it is RECOMMENDED to allocate unique code points for these
TE link attribute TLVs in the OSPFv2 Extended Link TLV Sub-TLV
Registry [RFC7684] and in the OSPFv3 Extended LSA Sub-TLV Registry
[RFC8362]. For each reused TLV, the code point will be defined in an
IETF document along with the expected use-case(s).
4. Reused TE link attributes
This section defines the use case and code points for the OSPFv2
Extended Link TLV Sub-TLV Registry and OSPFv3 Extended LSA Sub-TLV
Registry for some of the link attributes that have been originally
defined for TE or GMPLS.
Remote interface IP address and Link Local/Remote Identifiers have
been added as sub-TLVs of OSPFv2 Extended Link TLV by [RFC8379].
Link Local/Remote Identifiers are already included in the OSPFv3
Router-Link TLV [RFC8362].
4.1. Shared Risk Link Group (SRLG)
The SRLG of a link can be used in IPFRR to compute a backup path that
does not share any SRLG group with the protected link.
To advertise the SRLG of the link in the OSPFv2 Extended Link TLV,
the same format for the sub-TLV defined in section 1.3 of [RFC4203]
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is used and TLV type TBD1 is used. Similarly, for OSPFv3 to
advertise the SRLG in the OSPFv3 Router-Link TLV, TLV type TBD2 is
used.
4.2. Extended Metrics
[RFC3630] defines several link bandwidth types. [RFC7471] defines
extended link metrics that are based on link bandwidth, delay and
loss characteristics. All these can be used to compute best paths
within an OSPF area to satisfy requirements for bandwidth, delay
(nominal or worst case) or loss.
To advertise extended link metrics in the OSPFv2 Extended Link TLV,
the same format for the sub-TLVs defined in [RFC7471] is used with
the following TLV types:
TBD3 - Unidirectional Link Delay
TBD4 - Min/Max Unidirectional Link Delay
TBD5 - Unidirectional Delay Variation
TBD6 - Unidirectional Link Loss
TBD7 - Unidirectional Residual Bandwidth
TBD8 - Unidirectional Available Bandwidth
TBD9 - Unidirectional Utilized Bandwidth
To advertise extended link metrics in the OSPFv3 Extended LSA Router-
Link TLV, the same format for the sub-TLVs defined in [RFC7471] is
used with the following TLV types:
TBD10 - Unidirectional Link Delay
TBD11 - Min/Max Unidirectional Link Delay
TBD12 - Unidirectional Delay Variation
TBD13 - Unidirectional Link Loss
TBD14 - Unidirectional Residual Bandwidth
TBD15 - Unidirectional Available Bandwidth
TBD16 - Unidirectional Utilized Bandwidth
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4.3. Traffic Engineering Metric
[RFC3630] defines Traffic Engineering Metric.
To advertise the Traffic Engineering Metric in the OSPFv2 Extended
Link TLV, the same format for the sub-TLV defined in section 2.5.5 of
[RFC3630] is used and TLV type TBD27 is used. Similarly, for OSPFv3
to advertise the Traffic Engineering Metric in the OSPFv3 Router-Link
TLV, TLV type TBD28 is used.
4.4. Administrative Group
[RFC3630] and [RFC7308] define the Administrative Group and Extended
Administrative Group sub-TLVs respectively.
One use case where advertisement of the Extended Administrative
Group(s) for a link is required is described in
[I-D.ietf-lsr-flex-algo].
To advertise the Administrative Group and Extended Administrative
Group in the OSPFv2 Extended Link TLV, the same format for the sub-
TLVs defined in [RFC3630] and [RFC7308] is used with the following
TLV types:
TBD17 - Administrative Group
TBD18 - Extended Administrative Group
To advertise Administrative Group and Extended Administrative Group
in the OSPFv3 Router-Link TLV, the same format for the sub-TLVs
defined in [RFC3630] and [RFC7308] is used with the following TLV
types:
TBD19 - Administrative Group
TBD20 - Extended Administrative Group
5. Advertisement of Application Specific Values
Multiple applications can utilize link attributes that are advertised
by OSPF. Some examples of applications using the link attributes are
Segment Routing Traffic Engineering and LFA [RFC5286].
In some cases the link attribute MAY have different values for
different applications. An example could be SRLG [Section 4.1],
where values used by LFA could be different then the values used by
Segment Routing Traffic Engineering.
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To allow advertisement of the application specific values of the link
attribute, a new Application Specific Link Attributes (ASLA) sub-TLV
is defined. The ASLA sub-TLV is a sub-TLV of the OSPFv2 Extended
Link TLV [RFC7471] and OSPFv3 Router-Link TLV [RFC8362]. The ASLA
sub-TLV is an optional sub-TLV and can appear multiple times in the
OSPFv2 Extended Link TLV and OSPFv3 Router-Link TLV. It has the
following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SABML | UDABML | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Standard Application Bit-Mask |
+- -+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User Defined Application Bit-Mask |
+- -+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Attribute sub-sub-TLVs |
+- -+
| ... |
where:
Type: TBD21 (OSPFv2), TBD22 (OSPFv3)
Length: variable
SABML: Standard Application Bit-Mask Length. It MUST be a
multiple of 4 bytes. If the Standard Application Bit-Mask is not
present, the Standard Application Bit-Mask Length MUST be set to
0.
UDABML: User Defined Application Bit-Mask Length. It MUST be a
multiple of 4 bytes. If the User Defined Application Bit-Mask is
not present, the User Defined Application Bit-Mask Length MUST be
set to 0.
Standard Application Bit-Mask: Optional set of bits, where each
bit represents a single standard application. Bits are defined in
[I-D.ietf-isis-te-app], which also request a new IANA "Link
Attribute Applications" registry under "Interior Gateway Protocol
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(IGP) Parameters" for them. The bits are repeated here for
informational purpose:
Bit-0: RSVP Traffic Engineering
Bit-1: Segment Routing Traffic Engineering
Bit-2: Loop Free Alternate (LFA). Includes all LFA types
Bit-3: Flexible Algorithm
User Defined Application Bit-Mask: Optional set of bits, where
each bit represents a single user defined application.
Standard Application Bits are defined/sent starting with Bit 0.
Additional bit definitions that are defined in the future SHOULD be
assigned in ascending bit order so as to minimize the number of
octets that will need to be transmitted.
User Defined Application bits have no relationship to Standard
Application bits and are NOT managed by IANA or any other standards
body. It is recommended that bits are used starting with Bit 0 so as
to minimize the number of octets required to advertise all of them.
Undefined bits in both Bit-Masks MUST be transmitted as 0 and MUST be
ignored on receipt. Bits that are NOT transmitted MUST be treated as
if they are set to 0 on receipt.
If the link attribute advertisement is limited to be used by a
specific set of applications, corresponding Bit-Masks MUST be present
and application specific bit(s) MUST be set for all applications that
use the link attributes advertised in the ASLA sub-TLV.
Application Bit-Masks apply to all link attributes that support
application specific values and are advertised in the ASLA sub-TLV.
The advantage of not making the Application Bit-Masks part of the
attribute advertisement itself is that we can keep the format of the
link attributes that have been defined previously and reuse the same
format when advertising them in the ASLA sub-TLV.
When neither the Standard Application Bits nor the User Defined
Application bits are set (i.e., both SABML and UDABML are 0) in the
ASLA sub-TLV, then the link attributes included in it MUST be
considered as being applicable to all applications.
If, however, another advertisement of the same link attribute
includes any Application Bit-Mask in the ASLA sub-TLV, applications
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that are listed in the Application Bit-Masks of such ASLA sub-TLV
SHOULD use the attribute advertisement which has the application
specific bit set in the Application Bit-Masks.
If the same application is listed in the Application Bit-Masks of
more then one ASLA sub-TLV, the application SHOULD use the first
advertisement and ignore any subsequent advertisements of the same
attribute. This situation SHOULD be logged as an error.
This document defines the initial set of link attributes that MUST
use ASLA sub-TLV if advertised in the OSPFv2 Extended Link TLV or in
the OSPFv3 Router-Link TLV. If the ASLA sub-TLV includes any link
attribute(s) NOT listed below, they MUST be ignored. Documents which
define new link attributes MUST state whether the new attributes
support application specific values and as such MUST be advertised in
an ASLA sub-TLV. The link attributes that MUST be advertised in ASLA
sub-TLVs are:
- Shared Risk Link Group
- Unidirectional Link Delay
- Min/Max Unidirectional Link Delay
- Unidirectional Delay Variation
- Unidirectional Link Loss
- Unidirectional Residual Bandwidth
- Unidirectional Available Bandwidth
- Unidirectional Utilized Bandwidth
- Administrative Group
- Extended Administrative Group
- Traffic Engineering Metric
6. Maximum Link Bandwidth
Maximum link bandwidth is an application independent attribute of the
link that is defined in [RFC3630]. Because it is an application
independent attribute, it MUST NOT be advertised in ASLA sub-TLV.
Instead, it MAY be advertised as a sub-TLV of the Extended Link
Opaque LSA Extended Link TLV in OSPFv2 [RFC7684] or sub-TLV of OSPFv3
E-Router-LSA Router-Link TLV in OSPFv3 [RFC8362].
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To advertise the Maximum link bandwidth in the OSPFv2 Extended Link
TLV, the same format for sub-TLV defined in [RFC3630] is used with
TLV type TBD23.
To advertise the Maximum link bandwidth in the OSPFv3 Router-Link
TLV, the same format for sub-TLV defined in [RFC3630] is used with
TLV type TBD24.
7. Local Interface IPv6 Address Sub-TLV
The Local Interface IPv6 Address Sub-TLV is an application
independent attribute of the link that is defined in [RFC5329].
Because it is an application independent attribute, it MUST NOT be
advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a
sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362].
To advertise the Local Interface IPv6 Address Sub-TLV in the OSPFv3
Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is
used with TLV type TBD25.
8. Remote Interface IPv6 Address Sub-TLV
The Remote Interface IPv6 Address Sub-TLV is an application
independent attribute of the link that is defined in [RFC5329].
Because it is an application independent attribute, it MUST NOT be
advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a
sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362].
To advertise the Remote Interface IPv6 Address Sub-TLV in the OSPFv3
Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is
used with TLV type TBD26.
9. Deployment Considerations
If link attributes are advertised associated with zero length
application bit masks for both standard applications and user defined
applications, then that set of link attributes MAY be used by any
application. If support for a new application is introduced on any
node in a network in the presence of such advertisements, these
advertisements MAY be used by the new application. If this is not
what is intended, then existing advertisements MUST be readvertised
with an explicit set of applications specified before a new
application is introduced.
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10. Attribute Advertisements and Enablement
This document defines extensions to support the advertisement of
application specific link attributes.
Whether the presence of link attribute advertisements for a given
application indicates that the application is enabled on that link
depends upon the application. Similarly, whether the absence of link
attribute advertisements indicates that the application is not
enabled depends upon the application.
In the case of RSVP-TE, the advertisement of application specific
link attributes implies that RSVP is enabled on that link.
In the case of SRTE, advertisement of application specific link
attributes does NOT indicate enablement of SRTE. The advertisements
are only used to support constraints which may be applied when
specifying an explicit path. SRTE is implicitly enabled on all links
which are part of the Segment Routing enabled topology independent of
the existence of link attribute advertisements.
In the case of LFA, advertisement of application specific link
attributes does NOT indicate enablement of LFA on that link.
Enablement is controlled by local configuration.
In the case of Flexible Algorithm, advertisement of application
specific link attributes does NOT indicate enablement of Flexible
Algorithm on that link. Rather the attributes are used to determine
what links are included/excluded in the algorithm specific
constrained SPF. This is fully specified in
[I-D.ietf-lsr-flex-algo].
If, in the future, additional standard applications are defined to
use this mechanism, the specification defining this use MUST define
the relationship between application specific link attribute
advertisements and enablement for that application.
This document allows the advertisement of application specific link
attributes with no application identifiers i.e., both the Standard
Application Bit Mask and the User Defined Application Bit Mask are
not present Section 5. This supports the use of the link attribute
by any application. In the presence of an application where the
advertisement of link attribute advertisements is used to infer the
enablement of an application on that link (e.g., RSVP-TE), the
absence of the application identifier leaves ambiguous whether that
application is enabled on such a link. This needs to be considered
when making use of the &Internet-Draft The 'XML2RFC' version 3 Vocabulary June 2015
A.1.1.2. noModificationTrust200902
This produces additional text from Section 6.c.i of the TLP:
This document may not be modified, and derivative works of it may
not be created, except to format it for publication as an RFC or
to translate it into languages other than English.
*Note:* this clause is incompatible with RFCs that are published
on the Standards Track.
A.1.1.3. noDerivativesTrust200902
This produces the additional text from Section 6.c.ii of the TLP:
This document may not be modified, and derivative works of it may
not be created, and it may not be published except as an Internet-
Draft.
*Note:* this clause is incompatible with RFCs.
A.1.1.4. pre5378Trust200902
This produces the additional text from Section 6.c.iii of the TLP,
frequently called the "pre-5378 escape clause":
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s)
controlling the copyright in such materials, this document may not
be modified outside the IETF Standards Process, and derivative
works of it may not be created outside the IETF Standards Process,
except to format it for publication as an RFC or to translate it
into languages other than English.
See Section 4 of
<http://trustee.ietf.org/docs/IETF-Copyright-FAQ.pdf> for further
information about when to use this value.
*Note:* this text appears under "Copyright Notice", unless the
document was published before November 2009, in which case it
appears under "Status Of This Memo".
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A.1.2. Historic Values
A.1.2.1. Historic Values: '*trust200811'
The attribute values "trust200811", "noModificationTrust200811" and
"noDerivativesTrust200811" are similar to their "trust200902"
counterparts, except that they use text specified in <http://
trustee.ietf.org/license-info/archive/
IETF-Trust-License-Policy_11-10-08.pdf>.
A.1.2.2. Historic Values: '*3978'
The attribute values "full3978", "noModification3978" and
"noDerivatives3978" are similar to their counterparts above, except
that they use text specified in Section 5 of [RFC3978].
A.1.2.3. Historic Values: '*3667'
The attribute values "full3667", "noModification3667" and
"noDerivatives3667" are similar to their counterparts above, except
that they use text specified in Section 5 of [RFC3667].
A.1.2.4. Historic Values: '*2026'
The attribute values "full2026" and "noDerivativeWorks2026" are
similar to their counterparts above, except that they use text
specified in Section 10 of [RFC2026].
The special value "none" was also used back then, and denied the IETF
any rights beyond publication as Internet-Draft.
A.2. The /rfc/@submissionType Attribute
The RFC Editor publishes documents from different "document streams",
of which the "IETF stream" is the most prominent one. Other streams
are the "independent stream" (used for things such as administrative
information or April 1st RFCs), the "IAB stream" (Internet
Architecture Board) and the "IRTF stream" (Internet Research Task
Force).
The values for the attribute are "IETF" (the default value),
"independent", "IAB", and "IRTF".
Historically, this attribute did not affect the final appearance of
RFCs, except for subtle differences in Copyright notices. Nowadays
(as of [RFC5741]), the stream name appears in the first line of the
front page, and it also affects the text in the "Status Of This Memo"
section.
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For current documents, setting submissionType attribute will have the
following effect:
o For RFCs, the stream name appears in the upper left corner of the
first page (in Internet Drafts, this is either "Network Working
Group", or the value of the <workgroup> element).
o For RFCs, if affects the whole "Status Of This Memo" section (see
Section 3.2.2 of [RFC5741]).
o For all RFCs and Internet Drafts, it determines whether the
"Copyright Notice" mentions the Copyright on Code Components (see
TLP, Section "Text To Be Included in IETF Documents").
A.3. The /rfc/@consensus Attribute
For some of the publication streams (see Appendix A.2), the "Status
Of This Memo" section depends on whether there was a consensus to
publish (again, see Section 3.2.2 of [RFC5741]).
The consensus attribute can be used to supply this information. The
acceptable values are "true" (the default) and "false"; "yes" and
"no" from v2 are deprecated. The effect for the various streams is:
o "independent" and "IAB": none.
o "IETF": mention that there was an IETF consensus.
o "IRTF": mention that there was a research group consensus (where
the name of the research group is extracted from the <workgroup>
element).
Appendix B. The v3 Format and Processing Tools
This section describes topics that are specific to v3 processing
tools. Note that there is some discussion of tools in the main body
of the document as well. For example, some elements have
descriptions of how a processing tool might create output from the
element.
The expected design of the tools that will be used with v3 documents
includes:
o A "prep tool" that takes a v3 document, makes many checks, adds
and changes many attribute values, and creates a file that is a
"prepared document". The prepared document is a valid v3
document. The prep tool is described in [PREPTOOL].
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o The prep tool is expected to have many modes:
* RFC mode -- The mode used by the RFC Editor to process the
input from one of the RFC streams, and to process XML produced
during the RFC editing process. The restrictions on the
canonical XML for RFCs, as well as how the non-canonical
formats will look, are described at <https://
www.rfc-editor.org/rse/wiki/
doku.php?id=design:format-and-content-rfcs>.
* Draft mode -- The mode used by the Internet Draft submission
tool. The restrictions for the XML from this mode will be
described later.
* Diagnostic mode -- A mode that can be used by document authors
to look for errors or warnings before they submit their
documents for publication.
* Consolodation mode -- Produces output where no external
resources are required to render the file output. This
includes expanding the XInclude entities and DTD entities in
place, and changing all elements that have "src" attributes
with external links into either "data:" URI or content for the
element, as specified in [PREPTOOL].
o Formatting tools that will create HTML, PDF, plain text, and
possibly other output formats. These formatters will be created
by the IETF, but others can create such tools as well. The IETF
tools are expected to take prepared documents as input.
There may also be processing tools that are meant to run on the
computers of authors. These tools may be used to produce interim
versions of the non-canonical representations so that authors can see
how their XML might later be rendered; to create documents in
representations different than those supported by the RFC Editor; to
possibly create documents that are not meant to be Internet Drafts or
RFCs; and to convert XML that has external information into XML that
has that external information included.
The prep tool is expected to have clear error reporting, giving more
context than just a line number. For example, the error messages
should differentiate between errors in XML and those from the v3
format.
In v2, the grammar was specified as a DTD. In v3, the grammar is
specified only as Relax Next Generation (RNG). This means that tools
need to work from the RNG, not from a DTD. Some of the features of
the v3 grammar cannot be specified as a DTD.
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B.1. Including External Text with XInclude
All tools for the v3 format are expected to support XInclude
[XInclude]. XInclude specifies a processing model and syntax for
general purpose inclusion of information that is either on the
Internet or local to the user's computer.
In the v3 syntax, XInclude is expressed as the <xi:include> element.
To use this element, you need to include the "xi" namespace in the
<rfc> element; that is, you need to specify
xmlns:xi="http://www.w3.org/2001/XInclude"
as one of the attributes in the <rfc> element.
The most common way to use <xi:include> is to pull in references that
are already formed as XML. Currently, this can be done from
xml2rfc.tools.ietf.org, but later is expected to be from the RFC
Editor. For example, if a document has three normative references,
all RFCs, the document might contain:
<references>
<xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/
bibxml/reference.RFC.2119.xml"/>
<xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/
bibxml/reference.RFC.4869.xml"/>
<xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/
bibxml/reference.RFC.7169.xml"/>
</references>
<xi:include> can be used anywhere an XML element could be used (but
not where free text is used). For example, if three Internet Drafts
are all including a particular paragraph or section verbatim, that
text can be kept either in a file or somewhere on the web, and be
included with <xi:include>. An example of pulling something from the
local disk would be:
<x:include href="file://home/chris/ietf/drafts/commontext.xml"/>
In general, XInclude should be used instead of ENTITY references and
XML Processor Instructions (PIs) that allow external inclusions.
B.2. Anchors and IDs
People writing and reading Internet Drafts and RFCs often want to
make reference to specific locations in those documents. In the case
of RFC authors, it is common to want to reference another part of
their document, such as "see Section 3.2 of this document". Readers,
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on the other hand, want to reference part of documents that they
didn't write, such as "see Section 3.2 of RFC 6949". The XML
vocabulary in this document attempts to support both sets of people.
Authors can leave anchors in a document that can later be used for
references with the "anchor" attribute. Anchors can be included in
the following elements: <artwork>, <aside>, <blockquote>, <cref>,
<figure>, <li>, <reference>, <referencegroup>, <section>,
<sourcecode>, <t>, and <table>. The author can then refer to that
anchor in the "target" attribute of the <xref> element.
Readers can refer to any element that has an "anchor" attribute by
that attribute. Note, however, that most of the time, elements won't
have anchors. In the common case, the reader wants to refer to an
element that does not have an "anchor" attribute, but that element
has "pn" attribute.
Processing tools add the "pn" attribute to many elements during
processing. This attribute and its value are automatically generated
by the tool if the attribute is not there; if the attribute is
already there, the tool may replace the value.
B.2.1. Overlapping Values
In the HTML representation of this XML vocabulary, both anchors and
"pn" attributes will be used in the "id" attributes of elements.
Thus, there can be no overlap between the names entered in "anchor"
attributes, in "slugifiedName" attributes, and those that are
generated for the "pn" attributes. Also, there are some values for
the "anchor" values that are reserved for sections, and those
sections can only have those anchor values.
The following rules prevent this overlap:
o "pn" for regular sections always has the format "s-nnn", where
"nnn" is the section or appendix number. For example, this would
be "s-2.1.3" for Section 2.1.3 and "s-a" for Appendix A. For the
<abstract> element, it is always "s-abstract". For the <note>
element, it is always "s-note-nnn", where "nnn" is a sequential
value. For the <boilerplate> element, it is always
"s-boilerplate-nnn", where "nnn" is a sequential value.
o "pn" for <figure> elements always has the format "f-nnn", where
"nnn" is the figure number. For example, this would be "f-5" for
Figure 5.
o "pn" for <table> elements always has the format "t-nnn", where
"nnn" is the table number. For example, this would be "t-5" for
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Table 5.
o "pn" for all elements not listed above always has the format
"p-nnn-mmm", where "nnn" is the section number and "mmm" is the
relative position in the section. For example, this would be
"p-2.1.3-7" for the seventh part number in Section 2.1.3.
o "slugifiedName" always has the format "n-ttt", where "ttt" is the
text of the name after slugification. For example, this would be
"n-protocol-overview" for the name "Protocol Overview". The
actual conversions done in slugification will be specified at a
later time.
o Anchors must never overlap with any of the above. The easiest way
to assure that is to not pick an anchor name that starts with a
single letter followed by a hyphen. If an anchor does overlap
with one of the types of names above, the processing tool will
reject the document.
B.3. Attributes Controlled by the Prep Tool
Many elements in the v3 vocabulary have new attributes whose role is
to hold values generated by the prep tool. These attributes can
exist in documents that are input to the prep tool; however, any of
these attributes might be added, removed, or changed by the prep
tool. Thus, it is explicitly unsafe for a document author to include
these attributes and expect that their values will survive processing
by the prep tool.
The attributes that are controlled by the prep tool are:
o The "pn" attribute in any element -- The number for this item
within the section. The numbering is shared with other elements
of a section. The "pn" attribute is added to many block-level
elements inside sections.
o <artwork> originalSrc -- This attribute is filled with the
original value of the "src" attribute if that attribute is removed
by the prep tool.
o <iref> "irefid" attribute -- This attribute is filled with an
identifier used when creating indexes.
o <name> "slugifiedName" attribute -- This attribute is filled with
a "slugified" version of the text in the element. This attribute
can be used in the output formats for elements that have both
names and numbers.
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o <relref> "derivedLink" attribute -- This attribute is filled with
the link that is derived from combining the URI from the reference
and the relative part that is either a copy of the "relative"
attribute or a section number derived from the "section"
attribute.
o <relref> "derivedRemoteContent" attribute -- If the <relref>
element has text content, this attribute is filled with that
content; the "displayFormat" attribute is set to "bare" if that
attribute is not already set. If the <relref> element has no text
content, this attribute is filled with the text for the remote
link, such as "Section 2.3" or "Table 5". The prep tool might
determine this text by reading the target reference and, if it is
a RFC or Internet-Draft in the v3 format, finding the anchor given
in the "relative" attribute or derived from the "section"
attribute, and using the title of that element. If the reference
is not an RFC or Internet-Draft in the v3 format, the text
fragment is simply the value of the "relative" or "section"
attribute. This will rarely produce a good result in formatted
output so, for these documents, the <relref> element should
contain text content.
o <rfc> "expiresDate" attribute -- This attribute is filled with the
date that an Internet Draft expires. The date is in the format
yyyy-mm-dd.
o <rfc> "scripts" attribute -- This attribute is filled with a list
of scripts needed to render this document. The list is comma-
separated, with no spaces allowed. The order is unimportant. The
names come from [UAX24]. For example, if the document has Chinese
characters in it, the value might be "Common,Latin,Han".
o <sourcecode> "originalSrc" attribute -- This attribute is filled
with the original value of the "src" attribute if that attribute
is removed by the prep tool.
o <xref> "derivedContent" attribute -- This attribute is filled in
if there is no content in the <xref> element. The value for this
attribute based on the value in the "displayFormat" attribute. [[
More needs to be said here about the exact values based on the
value of the "format" attribute, drawing from xref/@format ]]
In addition, note that the contents of the <boilerplate> element is
controlled by the prep tool.
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quot;any application" encoding.
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11. Backward Compatibility
Link attributes may be concurrently advertised in both the TE Opaque
LSA and the Extended Link Opaque LSA in OSPFv2 and the OSPFv3 Intra-
Area-TE-LSA and OSPFv3 Extended LSA Router-Link TLV in OSPFv3.
In fact, there is at least one OSPF implementation that utilizes the
link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP
TE applications. For example, this implementation of LFA and remote
LFA utilizes links attributes such as Shared Risk Link Groups (SRLG)
[RFC4203] and Admin Group [[RFC3630] advertised in TE Opaque LSAs.
These applications are described in [RFC5286], [RFC7490], [RFC7916]
and [RFC8102].
When an OSPF routing domain includes routers using link attributes
from the OSPFv2 TE Opaque LSAs or the OSPFv3 Intra-Area-TE-LSA for
Non-RSVP TE applications such as LFA, OSPF routers in that domain
SHOULD continue to advertise such OSPFv2 TE Opaque LSAs or the OSPFv3
Intra-Area-TE-LSA. If there are also OSPF routers using the link
attributes described herein for any other application, OSPF routers
in the routing domain will also need to advertise these attributes in
OSPFv2 Extended Link Attributes LSAs or OSPFv3 E-Router-LSA. In such
a deployment, the advertised attributes SHOULD be the same and Non-
RSVP application access to link attributes is a matter of local
policy.
12. Security Considerations
Implementations must assure that malformed TLV and Sub-TLV
permutations do not result in errors that cause hard OSPF failures.
13. IANA Considerations
13.1. OSPFv2
OSPFv2 Extended Link TLV Sub-TLVs registry [RFC7684] defines sub-TLVs
at any level of nesting for OSPFv2 Extended Link TLVs. This
specification updates OSPFv2 Extended Link TLV sub-TLVs registry with
the following TLV types:
TBD21 (10 Recommended) - Application Specific Link Attributes
TBD1 (11 Recommended) - Shared Risk Link Group
TBD3 (12 Recommended) - Unidirectional Link Delay
TBD4 (13 Recommended) - Min/Max Unidirectional Link Delay
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TBD5 (14 Recommended) - Unidirectional Delay Variation
TBD6 (15 Recommended) - Unidirectional Link Loss
TBD7 (16 Recommended) - Unidirectional Residual Bandwidth
TBD8 (17 Recommended) - Unidirectional Available Bandwidth
TBD9 (18 Recommended) - Unidirectional Utilized Bandwidth
TBD9 (19 Recommended) - Administrative Group
TBD17 (20 Recommended) - Extended Administrative Group
TBD23 (21 Recommended) - Maximum Link Bandwidth
TBD27 (22 Recommended) - Traffic Engineering Metric
13.2. OSPFv3
OSPFv3 Extended LSA Sub-TLV Registry [RFC8362] defines sub-TLVs at
any level of nesting for OSPFv3 Extended LSAs. This specification
updates OSPFv3 Extended LSA Sub-TLV Registry with the following TLV
types:
TBD22 (9 Recommended) - Application Specific Link Attributes
TBD2 (10 Recommended) - Shared Risk Link Group
TBD10 (11 Recommended) - Unidirectional Link Delay
TBD11 (12 Recommended) - Min/Max Unidirectional Link Delay
TBD12 (13 Recommended) - Unidirectional Delay Variation
TBD13 (14 Recommended) - Unidirectional Link Loss
TBD14 (15 Recommended) - Unidirectional Residual Bandwidth
TBD15 (16 Recommended) - Unidirectional Available Bandwidth
TBD16 (17 Recommended) - Unidirectional Utilized Bandwidth
TBD19 (18 Recommended) - Administrative Group
TBD20 (19 Recommended) - Extended Administrative Group
TBD24 (20 Recommended) - Maximum Link Bandwidth
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TBD25 (21 Recommended) - Local Interface IPv6 Address Sub-TLV
TBD26 (22 Recommended) - Local Interface IPv6 Address Sub-TLV
TBD28 (23 Recommended) - Traffic Engineering Metric
14. Acknowledgments
Thanks to Chris Bowers for his review and comments.
15. References
15.1. Normative References
[RFC2119] Bradner, S., "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>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003,
<https://www.rfc-editor.org/info/rfc3630>.
[RFC5329] Ishiguro, K., Manral, V., Davey, A., and A. Lindem, Ed.,
"Traffic Engineering Extensions to OSPF Version 3",
RFC 5329, DOI 10.17487/RFC5329, September 2008,
<https://www.rfc-editor.org/info/rfc5329>.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<https://www.rfc-editor.org/info/rfc5340>.
[RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework",
RFC 5714, DOI 10.17487/RFC5714, January 2010,
<https://www.rfc-editor.org/info/rfc5714>.
[RFC7308] Osborne, E., "Extended Administrative Groups in MPLS
Traffic Engineering (MPLS-TE)", RFC 7308,
DOI 10.17487/RFC7308, July 2014,
<https://www.rfc-editor.org/info/rfc7308>.
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <https://www.rfc-editor.org/info/rfc7684>.
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[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
15.2. Informative References
[I-D.ietf-idr-ls-distribution]
Gredler, H., Medved, J., Previdi, S., Farrel, A., and S.
Ray, "North-Bound Distribution of Link-State and TE
Information using BGP", draft-ietf-idr-ls-distribution-13
(work in progress), October 2015.
[I-D.ietf-isis-te-app]
Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and
J. Drake, "IS-IS TE Attributes per application", draft-
ietf-isis-te-app-05 (work in progress), October 2018.
[I-D.ietf-lsr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex-
algo-00 (work in progress), May 2018.
[I-D.ietf-ospf-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
Extensions for Segment Routing", draft-ietf-ospf-segment-
routing-extensions-25 (work in progress), April 2018.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
<https://www.rfc-editor.org/info/rfc4203>.
[RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
IP Fast Reroute: Loop-Free Alternates", RFC 5286,
DOI 10.17487/RFC5286, September 2008,
<https://www.rfc-editor.org/info/rfc5286>.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<https://www.rfc-editor.org/info/rfc7471>.
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[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015,
<https://www.rfc-editor.org/info/rfc7490>.
[RFC7855] Previdi, S., Ed., Filsfils, C., Ed., Decraene, B.,
Litkowski, S., Horneffer, M., and R. Shakir, "Source
Packet Routing in Networking (SPRING) Problem Statement
and Requirements", RFC 7855, DOI 10.17487/RFC7855, May
2016, <https://www.rfc-editor.org/info/rfc7855>.
[RFC7916] Litkowski, S., Ed., Decraene, B., Filsfils, C., Raza, K.,
Horneffer, M., and P. Sarkar, "Operational Management of
Loop-Free Alternates", RFC 7916, DOI 10.17487/RFC7916,
July 2016, <https://www.rfc-editor.org/info/rfc7916>.
[RFC8102] Sarkar, P., Ed., Hegde, S., Bowers, C., Gredler, H., and
S. Litkowski, "Remote-LFA Node Protection and
Manageability", RFC 8102, DOI 10.17487/RFC8102, March
2017, <https://www.rfc-editor.org/info/rfc8102>.
[RFC8379] Hegde, S., Sarkar, P., Gredler, H., Nanduri, M., and L.
Jalil, "OSPF Graceful Link Shutdown", RFC 8379,
DOI 10.17487/RFC8379, May 2018,
<https://www.rfc-editor.org/info/rfc8379>.
Authors' Addresses
Peter Psenak (editor)
Cisco Systems, Inc.
Eurovea Centre, Central 3
Pribinova Street 10
Bratislava 81109
Slovakia
Email: ppsenak@cisco.com
Acee Lindem
Cisco Systems
301 Midenhall Way
Cary, NC 27513
USA
Email: acee@cisco.com
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Les Ginsberg
Cisco Systems
821 Alder Drive
MILPITAS, CA 95035
USA
Email: ginsberg@cisco.com
Wim Henderickx
Nokia
Copernicuslaan 50
Antwerp, 2018 94089
Belgium
Email: wim.henderickx@nokia.com
Jeff Tantsura
Nuage Networks
US
Email: jefftant.ietf@gmail.com
Hannes Gredler
RtBrick Inc.
Email: hannes@rtbrick.com
John Drake
Juniper Networks
Email: jdrake@juniper.net
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