draft-ietf-ospf-te-link-attr-reuse-01.txt   draft-ietf-ospf-te-link-attr-reuse-02.txt 
Network Working Group P. Psenak Network Working Group P. Psenak
Internet-Draft A. Lindem Internet-Draft A. Lindem
Intended status: Standards Track L. Ginsberg Intended status: Standards Track L. Ginsberg
Expires: February 23, 2018 Cisco Systems Expires: April 30, 2018 Cisco Systems
W. Henderickx W. Henderickx
Nokia Nokia
J. Tantsura J. Tantsura
Individual Individual
H. Gredler H. Gredler
RtBrick Inc. RtBrick Inc.
J. Drake J. Drake
Juniper Networks Juniper Networks
August 22, 2017 October 27, 2017
OSPFv2 Link Traffic Engineering (TE) Attribute Reuse OSPFv2 Link Traffic Engineering (TE) Attribute Reuse
draft-ietf-ospf-te-link-attr-reuse-01.txt draft-ietf-ospf-te-link-attr-reuse-02.txt
Abstract Abstract
Various link attributes have been defined in OSPFv2 in the context of Various link attributes have been defined in OSPFv2 in the context of
the MPLS Traffic Engineering (TE) and GMPLS. Many of these link the MPLS Traffic Engineering (TE) and GMPLS. Many of these link
attributes can be used for purposes other than MPLS Traffic attributes can be used for purposes other than MPLS Traffic
Engineering or GMPLS. This documents defines how to distribute such Engineering or GMPLS. This documents defines how to distribute such
attributes in OSPFv2 for applications other than MPLS Traffic attributes in OSPFv2 for applications other than MPLS Traffic
Engineering or GMPLS purposes. Engineering or GMPLS purposes.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 23, 2018. This Internet-Draft will expire on April 30, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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This document may contain material from IETF Documents or IETF This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November Contributions published or made publicly available before November
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skipping to change at page 2, line 42 skipping to change at page 2, line 42
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3
2. Link attributes examples . . . . . . . . . . . . . . . . . . 3 2. Link attributes examples . . . . . . . . . . . . . . . . . . 3
3. Advertising Link Attributes . . . . . . . . . . . . . . . . . 4 3. Advertising Link Attributes . . . . . . . . . . . . . . . . . 4
3.1. TE Opaque LSA . . . . . . . . . . . . . . . . . . . . . . 4 3.1. TE Opaque LSA . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Extended Link Opaque LSA . . . . . . . . . . . . . . . . 5 3.2. Extended Link Opaque LSA . . . . . . . . . . . . . . . . 5
3.3. Selected Approach . . . . . . . . . . . . . . . . . . . . 5 3.3. Selected Approach . . . . . . . . . . . . . . . . . . . . 5
4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 6 4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 6
4.1. Remote interface IP address . . . . . . . . . . . . . . . 6 4.1. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 6
4.2. Link Local/Remote Identifiers . . . . . . . . . . . . . . 6 4.2. Extended Metrics . . . . . . . . . . . . . . . . . . . . 6
4.3. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 7 4.3. Administrative Group . . . . . . . . . . . . . . . . . . 7
4.4. Extended Metrics . . . . . . . . . . . . . . . . . . . . 7
5. Advertisement of Application Specific Values . . . . . . . . 7 5. Advertisement of Application Specific Values . . . . . . . . 7
6. Deployment Considerations . . . . . . . . . . . . . . . . . . 10 6. Deployment Considerations . . . . . . . . . . . . . . . . . . 10
7. Attribute Advertisements and Enablement . . . . . . . . . . . 11 7. Attribute Advertisements and Enablement . . . . . . . . . . . 10
8. Backward Compatibility . . . . . . . . . . . . . . . . . . . 11 8. Backward Compatibility . . . . . . . . . . . . . . . . . . . 11
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12 9. Security Considerations . . . . . . . . . . . . . . . . . . . 12
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
12.1. Normative References . . . . . . . . . . . . . . . . . . 13 12.1. Normative References . . . . . . . . . . . . . . . . . . 12
12.2. Informative References . . . . . . . . . . . . . . . . . 13 12.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
Various link attributes have been defined in OSPFv2 [RFC2328] in the Various link attributes have been defined in OSPFv2 [RFC2328] in the
context of the MPLS traffic engineering and GMPLS. All these context of the MPLS traffic engineering and GMPLS. All these
attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV
advertised in the OSPFv2 TE Opaque LSA [RFC3630]. advertised in the OSPFv2 TE Opaque LSA [RFC3630].
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Extended Link TLV Sub-TLV Registry as defined in [RFC7684]. For each Extended Link TLV Sub-TLV Registry as defined in [RFC7684]. For each
reused TLV, the code point will be defined in an IETF document along reused TLV, the code point will be defined in an IETF document along
with the expected usecase(s). with the expected usecase(s).
4. Reused TE link attributes 4. Reused TE link attributes
This section defines the use case and code points for the OSPFv2 This section defines the use case and code points for the OSPFv2
Extended Link TLV Sub-TLV Registry for some of the link attributes Extended Link TLV Sub-TLV Registry for some of the link attributes
that have been originally defined for TE or GMPLS purposes. that have been originally defined for TE or GMPLS purposes.
4.1. Remote interface IP address Remote interface IP address and Link Local/Remote Identifiers have
been added as sub-TLVs of OSPFv2 Extended Link TLV by
The OSPFv2 description of an IP numbered point-to-point adjacency [I-D.ietf-ospf-link-overload].
does not include the remote IP address. As described in Section 2,
this makes the two-way connectivity check ambiguous in the presence
of the parallel point-to-point links between two OSPFv2 routers.
The Remote IP address of the link can also be used for Segment
Routing traffic engineering to identify the link in a set of parallel
links between two OSPFv2 routers
[I-D.ietf-ospf-segment-routing-extensions]. Similarly, the remote IP
address is useful in identifying individual parallel OSPF links
advertised in BGP Link-State as described in
[I-D.ietf-idr-ls-distribution].
To advertise the Remote interface IP address in the OSPFv2 Extended
Link TLV, the same format of the sub-TLV as defined in section 2.5.4.
of [RFC3630] is used and TLV type TBD1 is used.
4.2. Link Local/Remote Identifiers
The OSPFv2 description of an IP unnumbered point-to-point adjacency
does not include the remote link identifier. As described in
Section 2, this makes the two-way connectivity check ambiguous in the
presence of the parallel point-to-point IP unnumbered links between
two OSPFv2 routers.
The local and remote link identifiers can also be used for Segment
Routing traffic engineering to identify the link in a set of parallel
IP unnumbered links between two OSPFv2 routers
[I-D.ietf-ospf-segment-routing-extensions]. Similarly, these
identifiers are useful in identifying individual parallel OSPF links
advertised in BGP Link-State as described in
[I-D.ietf-idr-ls-distribution].
To advertise the link Local/Remote identifiers in the OSPFv2 Extended
Link TLV, the same format of the sub-TLV as defined in section 1.1.
of [RFC4203] is used and TLV type TBD2 is used.
4.3. Shared Risk Link Group (SRLG) 4.1. Shared Risk Link Group (SRLG)
The SRLG of a link can be used in IPFRR to compute a backup path that 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. does not share any SRLG group with the protected link.
To advertise the SRLG of the link in the OSPFv2 Extended Link TLV, To advertise the SRLG of the link in the OSPFv2 Extended Link TLV,
the same format of the sub-TLV as defined in section 1.3. of the same format of the sub-TLV as defined in section 1.3. of
[RFC4203] is used and TLV type TBD3 is used. [RFC4203] is used and TLV type TBD1 is used.
4.4. Extended Metrics 4.2. Extended Metrics
[RFC3630] defines several link bandwidth types. [RFC7471] defines [RFC3630] defines several link bandwidth types. [RFC7471] defines
extended link metrics that are based on link bandwidth, delay and extended link metrics that are based on link bandwidth, delay and
loss characteristics. All these can be used to compute best paths loss characteristics. All these can be used to compute best paths
within an OSPF area to satisfy requirements for bandwidth, delay within an OSPF area to satisfy requirements for bandwidth, delay
(nominal or worst case) or loss. (nominal or worst case) or loss.
To advertise extended link metrics in the OSPFv2 Extended Link TLV, To advertise extended link metrics in the OSPFv2 Extended Link TLV,
the same format of the sub-TLVs as defined in [RFC7471] is used with the same format of the sub-TLVs as defined in [RFC7471] is used with
following TLV types: following TLV types:
TBD4 - Unidirectional Link Delay TBD2 - Unidirectional Link Delay
TBD5 - Min/Max Unidirectional Link Delay TBD3 - Min/Max Unidirectional Link Delay
TBD6 - Unidirectional Delay Variation TBD4 - Unidirectional Delay Variation
TBD7 - Unidirectional Link Loss TBD5 - Unidirectional Link Loss
TBD8 - Unidirectional Residual Bandwidth TBD6 - Unidirectional Residual Bandwidth
TBD9 - Unidirectional Available Bandwidth TBD7 - Unidirectional Available Bandwidth
TBD8 - Unidirectional Utilized Bandwidth
TBD10 - Unidirectional Utilized Bandwidth 4.3. Administrative Group
[RFC3630] and [RFC7308] define Administrative Group and Extended
Administrative Group sub-TLVs.
One use case where advertisement of the Extended Administrative
Group(s) for a link is required is described in
[I-D.hegdeppsenak-isis-sr-flex-algo].
To advertise Administrative Group and Extended Administrative Group
in the OSPFv2 Extended Link TLV, the same format of the sub-TLVs as
defined in [RFC3630] and [RFC7308] is used with following TLV types:
TBD9 - Administrative Group
TBD10 - Extended Administrative Group
5. Advertisement of Application Specific Values 5. Advertisement of Application Specific Values
Multiple applications can utilize link attributes that are flooded by Multiple applications can utilize link attributes that are flooded by
OSPFv2. Some examples of applications using the link attributes are OSPFv2. Some examples of applications using the link attributes are
Segment Routing Traffic Engineering and LFA [RFC5286]. Segment Routing Traffic Engineering and LFA [RFC5286].
In some cases the link attribute only has a single value that is In some cases the link attribute only has a single value that is
applicable to all applications. An example is a Remote interface IP applicable to all applications. An example is a Remote interface IP
address [Section 4.1] or Link Local/Remote Identifiers [Section 4.2]. address or Link Local/Remote Identifiers
[I-D.ietf-ospf-link-overload].
In some cases the link attribute MAY have different values for In some cases the link attribute MAY have different values for
different applications. An example could be SRLG [Section 4.3], different applications. An example could be SRLG [Section 4.1],
where values used by LFA could be different then the values used by where values used by LFA could be different then the values used by
Segment Routing Traffic Engineering. Segment Routing Traffic Engineering.
To allow advertisement of the application specific values of the link To allow advertisement of the application specific values of the link
attribute, a new Extended Link Attribute sub-TLV of the Extended Link attribute, a new Extended Link Attribute sub-TLV of the Extended Link
TLV [RFC7471] is defined. The Extended Link Attribute sub-TLV is an TLV [RFC7471] is defined. The Extended Link Attribute sub-TLV is an
optional sub-TLV and can appear multiple times in the Extended Link optional sub-TLV and can appear multiple times in the Extended Link
TLV. It has following format: TLV. It has following format:
0 1 2 3 0 1 2 3
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| User Defined Application Bit-Mask | | User Defined Application Bit-Mask |
+- -+ +- -+
| ... | | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Attribute sub-sub-TLVs | | Link Attribute sub-sub-TLVs |
+- -+ +- -+
| ... | | ... |
where: where:
Type: TBD11, suggested value 14 Type: TBD11, suggested value 8
Length: variable Length: variable
SABML: Standard Application Bit-Mask Length. If the Standard SABML: Standard Application Bit-Mask Length. If the Standard
Application Bit-Mask is not present, the Standard Application Bit- Application Bit-Mask is not present, the Standard Application Bit-
Mask Length MUST be set to 0. Mask Length MUST be set to 0.
UDABML: User Defined Application Bit-Mask Length. If the User UDABML: User Defined Application Bit-Mask Length. If the User
Defined Application Bit-Mask is not present, the User Defined Defined Application Bit-Mask is not present, the User Defined
Application Bit-Mask Length MUST be set to 0. Application Bit-Mask Length MUST be set to 0.
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Standard Application Bit-Mask: Optional set of bits, where each Standard Application Bit-Mask: Optional set of bits, where each
bit represents a single standard application. The following bits bit represents a single standard application. The following bits
are defined by this document: are defined by this document:
Bit-0: RSVP Traffic Engineering Bit-0: RSVP Traffic Engineering
Bit-1: Segment Routing Traffic Engineering Bit-1: Segment Routing Traffic Engineering
Bit-2: Loop Free Alternate (LFA). Includes all LFA types. Bit-2: Loop Free Alternate (LFA). Includes all LFA types.
Bit-3: Flexible Algorithm as describe in
[I-D.hegdeppsenak-isis-sr-flex-algo].
User Defined Application Bit-Mask: Optional set of bits, where User Defined Application Bit-Mask: Optional set of bits, where
each bit represents a single user defined application. each bit represents a single user defined application.
Standard Application Bits are defined/sent starting with Bit 0. Standard Application Bits are defined/sent starting with Bit 0.
Additional bit definitions that may be defined in the future SHOULD Additional bit definitions that may be defined in the future SHOULD
be assigned in ascending bit order so as to minimize the number of be assigned in ascending bit order so as to minimize the number of
octets that will need to be transmitted. octets that will need to be transmitted.
User Defined Application bits have no relationship to Standard User Defined Application bits have no relationship to Standard
Application bits and are NOT managed by IANA or any other standards Application bits and are NOT managed by IANA or any other standards
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- Unidirectional Delay Variation - Unidirectional Delay Variation
- Unidirectional Link Loss - Unidirectional Link Loss
- Unidirectional Residual Bandwidth - Unidirectional Residual Bandwidth
- Unidirectional Available Bandwidth - Unidirectional Available Bandwidth
- Unidirectional Utilized Bandwidth - Unidirectional Utilized Bandwidth
- Administrative Group
- Extended Administrative Group
6. Deployment Considerations 6. Deployment Considerations
If link attributes are advertised associated with zero length If link attributes are advertised associated with zero length
application bit masks for both standard applications and user defined application bit masks for both standard applications and user defined
applications, then that set of link attributes MAY be used by any applications, then that set of link attributes MAY be used by any
application. If support for a new application is introduced on any application. If support for a new application is introduced on any
node in a network in the presence of such advertisements, these node in a network in the presence of such advertisements, these
advertisements MAY be used by the new application. If this is not advertisements MAY be used by the new application. If this is not
what is intended, then existing advertisements MUST be readvertised what is intended, then existing advertisements MUST be readvertised
with an explicit set of applications specified before a new with an explicit set of applications specified before a new
application is introduced. application is introduced.
7. Attribute Advertisements and Enablement 7. Attribute Advertisements and Enablement
This document defines extensions to support the advertisement of This document defines extensions to support the advertisement of
application specific link attributes. The presence or absence of application specific link attributes.
link attribute advertisements for a given application on a link does
NOT indicate the state of enablement of that application on that
link. Enablement of an application on a link is controlled by other
means.
For some applications, the concept of enablement is implicit. For Whether the presence of link attribute advertisements for a given
example, SRTE implicitly is enabled on all links which are part of application indicates that the application is enabled on that link
the Segment Routing enabled topology. Advertisement of link depends upon the application. Similarly, whether the absence of link
attributes supports constraints which may be applied when specifying attribute advertisements indicates that the application is not
an explicit path through that topology. enabled depends upon the application.
For other applications enablement is controlled by local In the case of RSVP-TE, the advertisement of application specific
configuration. For example, use of a link as an LFA can be link attributes implies that RSVP is enabled on that link.
controlled by local enablement/disablement and/or the use of
administrative tags.
It is an application specific policy as to whether a given link can In the case of SRTE, advertisement of application specific link
be used by that application even in the absence of any application attributes does NOT indicate enablement of SRTE. The advertisements
specific link attributes. 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.hegdeppsenak-isis-sr-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.
8. Backward Compatibility 8. Backward Compatibility
Link attributes may be concurrently advertised in both the TE Opaque Link attributes may be concurrently advertised in both the TE Opaque
LSA [RFC3630] and the Extended Link Opaque LSA [RFC7684]. LSA [RFC3630] and the Extended Link Opaque LSA [RFC7684].
In fact, there is at least one OSPF implementation that utilizes the In fact, there is at least one OSPF implementation that utilizes the
link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP
TE applications. For example, this implementation of LFA and remote TE applications. For example, this implementation of LFA and remote
LFA utilizes links attributes such as Shared Risk Link Groups (SRLG) LFA utilizes links attributes such as Shared Risk Link Groups (SRLG)
skipping to change at page 12, line 17 skipping to change at page 12, line 19
Implementations must assure that malformed TLV and Sub-TLV Implementations must assure that malformed TLV and Sub-TLV
permutations do not result in errors that cause hard OSPFv2 failures. permutations do not result in errors that cause hard OSPFv2 failures.
10. IANA Considerations 10. IANA Considerations
OSPFv2 Extended Link TLV Sub-TLVs registry [RFC7684] defines sub-TLVs OSPFv2 Extended Link TLV Sub-TLVs registry [RFC7684] defines sub-TLVs
at any level of nesting for OSPFv2 Extended Link TLVs. This at any level of nesting for OSPFv2 Extended Link TLVs. This
specification updates OSPFv2 Extended Link TLV sub-TLVs registry with specification updates OSPFv2 Extended Link TLV sub-TLVs registry with
the following TLV types: the following TLV types:
TBD1 (4 Recommended) - Remote interface IP address TBD1 (9 Recommended) - Shared Risk Link Group
TBD2 (5 Recommended) - Link Local/Remote Identifiers
TBD3 (6 Recommended) - Shared Risk Link Group
TBD4 (7 Recommended) - Unidirectional Link Delay
TBD5 (8 Recommended) - Min/Max Unidirectional Link Delay TBD2 (10 Recommended) - Unidirectional Link Delay
TBD6 (9 Recommended) - Unidirectional Delay Variation TBD3 (11 Recommended) - Min/Max Unidirectional Link Delay
TBD7 (10 Recommended) - Unidirectional Link Loss TBD4 (12 Recommended) - Unidirectional Delay Variation
TBD8 (11 Recommended) - Unidirectional Residual Bandwidth TBD5 (13 Recommended) - Unidirectional Link Loss
TBD9 (12 Recommended) - Unidirectional Available Bandwidth TBD6 (14 Recommended) - Unidirectional Residual Bandwidth
TBD10 (13 Recommended) - Unidirectional Utilized Bandwidth TBD7 (15 Recommended) - Unidirectional Available Bandwidth
TBD11 (14 Recommended) - Extended Link Attribute TBD8 (16 Recommended) - Unidirectional Utilized Bandwidth
This specification defines a new Link-Attribute-Applicability TBD9 (17 Recommended) - Administrative Group
Application Bits registry and defines following bits:
Bit-0 - Segment Routing Traffic Engineering TBD10 (18 Recommended) - Extended Administrative Group
Bit-1 - LFA TBD11 (8 Recommended) - Extended Link Attribute
11. Acknowledgments 11. Acknowledgments
Thanks to Chris Bowers for his review and comments. Thanks to Chris Bowers for his review and comments.
12. References 12. References
12.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, (TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003, <https://www.rfc- DOI 10.17487/RFC3630, September 2003,
editor.org/info/rfc3630>. <https://www.rfc-editor.org/info/rfc3630>.
[RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework", [RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework",
RFC 5714, DOI 10.17487/RFC5714, January 2010, RFC 5714, DOI 10.17487/RFC5714, January 2010,
<https://www.rfc-editor.org/info/rfc5714>. <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., [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <https://www.rfc-editor.org/info/rfc7684>. 2015, <https://www.rfc-editor.org/info/rfc7684>.
12.2. Informative References 12.2. Informative References
[I-D.hegdeppsenak-isis-sr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., and a.
arkadiy.gulko@thomsonreuters.com, "ISIS Segment Routing
Flexible Algorithm", draft-hegdeppsenak-isis-sr-flex-
algo-01 (work in progress), October 2017.
[I-D.ietf-idr-ls-distribution] [I-D.ietf-idr-ls-distribution]
Gredler, H., Medved, J., Previdi, S., Farrel, A., and S. Gredler, H., Medved, J., Previdi, S., Farrel, A., and S.
Ray, "North-Bound Distribution of Link-State and TE Ray, "North-Bound Distribution of Link-State and TE
Information using BGP", draft-ietf-idr-ls-distribution-13 Information using BGP", draft-ietf-idr-ls-distribution-13
(work in progress), October 2015. (work in progress), October 2015.
[I-D.ietf-ospf-link-overload]
Hegde, S., Sarkar, P., Gredler, H., Nanduri, M., and L.
Jalil, "OSPF Link Overload", draft-ietf-ospf-link-
overload-09 (work in progress), August 2017.
[I-D.ietf-ospf-segment-routing-extensions] [I-D.ietf-ospf-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H., Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
Extensions for Segment Routing", draft-ietf-ospf-segment- Extensions for Segment Routing", draft-ietf-ospf-segment-
routing-extensions-18 (work in progress), July 2017. routing-extensions-21 (work in progress), October 2017.
[I-D.ietf-rtgwg-lfa-manageability] [I-D.ietf-rtgwg-lfa-manageability]
Litkowski, S., Decraene, B., Filsfils, C., Raza, K., and Litkowski, S., Decraene, B., Filsfils, C., Raza, K., and
M. Horneffer, "Operational management of Loop Free M. Horneffer, "Operational management of Loop Free
Alternates", draft-ietf-rtgwg-lfa-manageability-11 (work Alternates", draft-ietf-rtgwg-lfa-manageability-11 (work
in progress), June 2015. in progress), June 2015.
[I-D.psarkar-rtgwg-rlfa-node-protection] [I-D.psarkar-rtgwg-rlfa-node-protection]
psarkar@juniper.net, p., Gredler, H., Hegde, S., Bowers, psarkar@juniper.net, p., Gredler, H., Hegde, S., Bowers,
C., Litkowski, S., and H. Raghuveer, "Remote-LFA Node C., Litkowski, S., and H. Raghuveer, "Remote-LFA Node
Protection and Manageability", draft-psarkar-rtgwg-rlfa- Protection and Manageability", draft-psarkar-rtgwg-rlfa-
node-protection-05 (work in progress), June 2014. node-protection-05 (work in progress), June 2014.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998, <https://www.rfc- DOI 10.17487/RFC2328, April 1998,
editor.org/info/rfc2328>. <https://www.rfc-editor.org/info/rfc2328>.
[RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
<https://www.rfc-editor.org/info/rfc4203>. <https://www.rfc-editor.org/info/rfc4203>.
[RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for [RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
IP Fast Reroute: Loop-Free Alternates", RFC 5286, IP Fast Reroute: Loop-Free Alternates", RFC 5286,
DOI 10.17487/RFC5286, September 2008, <https://www.rfc- DOI 10.17487/RFC5286, September 2008,
editor.org/info/rfc5286>. <https://www.rfc-editor.org/info/rfc5286>.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
Previdi, "OSPF Traffic Engineering (TE) Metric Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<https://www.rfc-editor.org/info/rfc7471>. <https://www.rfc-editor.org/info/rfc7471>.
[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N. [RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)", So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015, RFC 7490, DOI 10.17487/RFC7490, April 2015,
<https://www.rfc-editor.org/info/rfc7490>. <https://www.rfc-editor.org/info/rfc7490>.
 End of changes. 48 change blocks. 
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