< draft-ietf-idr-bgp-ls-segment-routing-ext-16.txt		draft-ietf-idr-bgp-ls-segment-routing-ext-18.txt >
	Inter-Domain Routing S. Previdi		Inter-Domain Routing S. Previdi
	Internet-Draft Huawei Technologies		Internet-Draft Huawei Technologies
	Intended status: Standards Track K. Talaulikar, Ed.		Intended status: Standards Track K. Talaulikar, Ed.
	Expires: December 29, 2019 C. Filsfils		Expires: October 17, 2021 C. Filsfils
	Cisco Systems, Inc.		Cisco Systems, Inc.
	H. Gredler		H. Gredler
	RtBrick Inc.		RtBrick Inc.
	M. Chen		M. Chen
	Huawei Technologies		Huawei Technologies
	June 27, 2019		April 15, 2021
	BGP Link-State extensions for Segment Routing		BGP Link-State extensions for Segment Routing
	draft-ietf-idr-bgp-ls-segment-routing-ext-16		draft-ietf-idr-bgp-ls-segment-routing-ext-18
	Abstract		Abstract
	Segment Routing (SR) allows for a flexible definition of end-to-end		Segment Routing (SR) allows for a flexible definition of end-to-end
	paths by encoding paths as sequences of topological sub-paths, called		paths by encoding paths as sequences of topological sub-paths, called
	"segments". These segments are advertised by routing protocols e.g.		"segments". These segments are advertised by routing protocols e.g.
	by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within		by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within
	IGP topologies.		IGP topologies.
	This document defines extensions to the BGP Link-state address-family		This document defines extensions to the BGP Link-state address-family
	skipping to change at page 2, line 4 ¶		skipping to change at page 2, line 4 ¶
	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 https://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 December 29, 2019.		This Internet-Draft will expire on October 17, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2021 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	skipping to change at page 2, line 35 ¶		skipping to change at page 2, line 35 ¶
	2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5		2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5
	2.1.1. SID/Label TLV . . . . . . . . . . . . . . . . . . . . 5		2.1.1. SID/Label TLV . . . . . . . . . . . . . . . . . . . . 5
	2.1.2. SR Capabilities TLV . . . . . . . . . . . . . . . . . 6		2.1.2. SR Capabilities TLV . . . . . . . . . . . . . . . . . 6
	2.1.3. SR Algorithm TLV . . . . . . . . . . . . . . . . . . 8		2.1.3. SR Algorithm TLV . . . . . . . . . . . . . . . . . . 8
	2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8		2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8
	2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 10		2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 10
	2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 11		2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 11
	2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 11		2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 11
	2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 12		2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 12
	2.2.3. L2 Bundle Member Attribute TLV . . . . . . . . . . . 14		2.2.3. L2 Bundle Member Attribute TLV . . . . . . . . . . . 14
	2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 16		2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 15
	2.3.1. Prefix SID TLV . . . . . . . . . . . . . . . . . . . 17		2.3.1. Prefix SID TLV . . . . . . . . . . . . . . . . . . . 16
	2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 18		2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 17
	2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 19		2.3.3. Source Router Identifier TLV . . . . . . . . . . . . 18
	2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 19		2.3.4. Source OSPF Router-ID TLV . . . . . . . . . . . . . . 19
			2.3.5. Range TLV . . . . . . . . . . . . . . . . . . . . . . 20
	2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 21		2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 21
	2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 22		2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 22
	3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25		3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
	3.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 25		3.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 25
	4. Manageability Considerations . . . . . . . . . . . . . . . . 25		4. Manageability Considerations . . . . . . . . . . . . . . . . 25
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 26		5. Security Considerations . . . . . . . . . . . . . . . . . . . 26
	6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27		6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28
	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 28		8. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
	8.1. Normative References . . . . . . . . . . . . . . . . . . 28		8.1. Normative References . . . . . . . . . . . . . . . . . . 28
	skipping to change at page 3, line 29 ¶		skipping to change at page 3, line 31 ¶
	topology. Adjacency segments represent a hop over a specific		topology. Adjacency segments represent a hop over a specific
	adjacency between two nodes in the IGP. A prefix segment is		adjacency between two nodes in the IGP. A prefix segment is
	typically a multi-hop path while an adjacency segment, in most of the		typically a multi-hop path while an adjacency segment, in most of the
	cases, is a one-hop path. Node and anycast segments are variations		cases, is a one-hop path. Node and anycast segments are variations
	of the prefix segment with their specific characteristics.		of the prefix segment with their specific characteristics.
	When Segment Routing is enabled in an IGP domain, segments are		When Segment Routing is enabled in an IGP domain, segments are
	advertised in the form of Segment Identifiers (SIDs). The IGP link-		advertised in the form of Segment Identifiers (SIDs). The IGP link-
	state routing protocols have been extended to advertise SIDs and		state routing protocols have been extended to advertise SIDs and
	other SR-related information. IGP extensions are described for: IS-		other SR-related information. IGP extensions are described for: IS-
	IS [I-D.ietf-isis-segment-routing-extensions], OSPFv2		IS [RFC8667], OSPFv2 [RFC8665] and OSPFv3 [RFC8666]. Using these
	[I-D.ietf-ospf-segment-routing-extensions] and OSPFv3
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. Using these
	extensions, Segment Routing can be enabled within an IGP domain.		extensions, Segment Routing can be enabled within an IGP domain.
	Segment Routing (SR) allows advertisement of single or multi-hop		Segment Routing (SR) allows advertisement of single or multi-hop
	paths. The flooding scope for the IGP extensions for Segment routing		paths. The flooding scope for the IGP extensions for Segment routing
	is IGP area-wide. Consequently, the contents of a Link State		is IGP area-wide. Consequently, the contents of a Link State
	Database (LSDB) or a Traffic Engineering Database (TED) has the scope		Database (LSDB) or a Traffic Engineering Database (TED) has the scope
	of an IGP area and therefore, by using the IGP alone it is not enough		of an IGP area and therefore, by using the IGP alone it is not enough
	to construct segments across multiple IGP Area or AS boundaries.		to construct segments across multiple IGP Area or AS boundaries.
	In order to address the need for applications that require		In order to address the need for applications that require
	skipping to change at page 5, line 47 ¶		skipping to change at page 5, line 47 ¶
	corresponding IGP TLV/sub-TLV described below.		corresponding IGP TLV/sub-TLV described below.
	2.1.1. SID/Label TLV		2.1.1. SID/Label TLV
	The SID/Label TLV is used as a sub-TLV by the SR Capabilities		The SID/Label TLV is used as a sub-TLV by the SR Capabilities
	(Section 2.1.2) and Segment Routing Local Block (SRLB)		(Section 2.1.2) and Segment Routing Local Block (SRLB)
	(Section 2.1.4) TLVs. This information is derived from the protocol		(Section 2.1.4) TLVs. This information is derived from the protocol
	specific advertisements.		specific advertisements.
	o IS-IS, as defined by the SID/Label sub-TLV in section 2.3 of		o IS-IS, as defined by the SID/Label sub-TLV in section 2.3 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SID/Label sub-TLV in section 2.1		o OSPFv2/OSPFv3, as defined by the SID/Label sub-TLV in section 2.1
	of [I-D.ietf-ospf-segment-routing-extensions] and section 3.1 of		of [RFC8665] and section 3.1 of [RFC8666].
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
	The TLV has the following format:		The TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label (variable) //		| SID/Label (variable) //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 6, line 38 ¶		skipping to change at page 6, line 36 ¶
	2.1.2. SR Capabilities TLV		2.1.2. SR Capabilities TLV
	The SR Capabilities TLV is used in order to advertise the node's SR		The SR Capabilities TLV is used in order to advertise the node's SR
	Capabilities including its Segment Routing Global Base (SRGB)		Capabilities including its Segment Routing Global Base (SRGB)
	range(s). In the case of IS-IS, the capabilities also include the		range(s). In the case of IS-IS, the capabilities also include the
	IPv4 and IPv6 support for the SR-MPLS forwarding plane. This		IPv4 and IPv6 support for the SR-MPLS forwarding plane. This
	information is derived from the protocol specific advertisements.		information is derived from the protocol specific advertisements.
	o IS-IS, as defined by the SR Capabilities sub-TLV in section 3.1 of		o IS-IS, as defined by the SR Capabilities sub-TLV in section 3.1 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in section		o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in section
	3.2 of [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3		3.2 of [RFC8665]. OSPFv3 leverages the same TLV as defined for
	leverages the same TLV as defined for OSPFv2.		OSPFv2.
	The SR Capabilities TLV has the following format:		The SR Capabilities TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Reserved |		| Flags | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 7, line 35 ¶		skipping to change at page 7, line 35 ¶
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 3: SR Capabilities TLV Format		Figure 3: SR Capabilities TLV Format
	Where:		Where:
	Type: 1034		Type: 1034
	Length: Variable. Minimum length is 12.		Length: Variable. Minimum length is 12.
	Flags: 1 octet of flags as defined in section 3.1 of		Flags: 1 octet of flags as defined in section 3.1 of [RFC8667] for
	[I-D.ietf-isis-segment-routing-extensions] for IS-IS. The flags		IS-IS. The flags are not currently defined for OSPFv2 and OSPFv3
	are not currently defined for OSPFv2 and OSPFv3 and MUST be set to		and MUST be set to 0 and ignored on receipt.
	0 and ignored on receipt.
	Reserved: 1 octet that MUST be set to 0 and ignored on receipt.		Reserved: 1 octet that MUST be set to 0 and ignored on receipt.
	One or more entries, each of which have the following format:		One or more entries, each of which have the following format:
	Range Size: 3 octet with a non-zero value indicating the number		Range Size: 3 octet with a non-zero value indicating the number
	of labels in the range.		of labels in the range.
	SID/Label TLV (as defined in Section 2.1.1) used as sub-TLV		SID/Label TLV (as defined in Section 2.1.1) used as sub-TLV
	which encodes the first label in the range. Since the SID/		which encodes the first label in the range. Since the SID/
	skipping to change at page 8, line 12 ¶		skipping to change at page 8, line 12 ¶
	range, only label encoding is valid under the SR Capabilities		range, only label encoding is valid under the SR Capabilities
	TLV.		TLV.
	2.1.3. SR Algorithm TLV		2.1.3. SR Algorithm TLV
	The SR Algorithm TLV is used in order to advertise the SR Algorithms		The SR Algorithm TLV is used in order to advertise the SR Algorithms
	supported by the node. This information is derived from the protocol		supported by the node. This information is derived from the protocol
	specific advertisements.		specific advertisements.
	o IS-IS, as defined by the SR-Algorithm sub-TLV in section 3.2 of		o IS-IS, as defined by the SR-Algorithm sub-TLV in section 3.2 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SR-Algorithm TLV in section 3.1		o OSPFv2/OSPFv3, as defined by the SR-Algorithm TLV in section 3.1
	of [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3 leverages		of [RFC8665]. OSPFv3 leverages the same TLV as defined for
	the same TLV as defined for OSPFv2.		OSPFv2.
	The SR Algorithm TLV has the following format:		The SR Algorithm TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Algorithm 1 | Algorithm... | Algorithm N |		| Algorithm 1 | Algorithm... | Algorithm N |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 9, line 6 ¶		skipping to change at page 9, line 6 ¶
	components other than IGP protocols. As an example, an application		components other than IGP protocols. As an example, an application
	or a controller may instruct a node to allocate a specific local SID.		or a controller may instruct a node to allocate a specific local SID.
	Therefore, in order for such applications or controllers to know the		Therefore, in order for such applications or controllers to know the
	range of local SIDs available, it is required that the node		range of local SIDs available, it is required that the node
	advertises its SRLB.		advertises its SRLB.
	This information is derived from the protocol specific		This information is derived from the protocol specific
	advertisements.		advertisements.
	o IS-IS, as defined by the SR Local Block sub-TLV in section 3.3 of		o IS-IS, as defined by the SR Local Block sub-TLV in section 3.3 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SR Local Block TLV in section		o OSPFv2/OSPFv3, as defined by the SR Local Block TLV in section
	3.3. of [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3		3.3. of [RFC8665]. OSPFv3 leverages the same TLV as defined for
	leverages the same TLV as defined for OSPFv2.		OSPFv2.
	The SRLB TLV has the following format:		The SRLB TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Reserved |		| Flags | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 9, line 45 ¶		skipping to change at page 9, line 45 ¶
	Figure 5: SRLB TLV Format		Figure 5: SRLB TLV Format
	Where:		Where:
	Type: 1036		Type: 1036
	Length: Variable. Minimum length is 12.		Length: Variable. Minimum length is 12.
	Flags: 1 octet of flags. The flags are as defined in section 3.3		Flags: 1 octet of flags. The flags are as defined in section 3.3
	of [I-D.ietf-isis-segment-routing-extensions] for IS-IS. The		of [RFC8667] for IS-IS. The flags are not currently defined for
	flags are not currently defined for OSPFv2 and OSPFv3 and MUST be		OSPFv2 and OSPFv3 and MUST be set to 0 and ignored on receipt.
	set to 0 and ignored on receipt.
	Reserved: 1 octet that MUST be set to 0 and ignored on receipt.		Reserved: 1 octet that MUST be set to 0 and ignored on receipt.
	One or more entries corresponding to sub-range(s), each of which		One or more entries corresponding to sub-range(s), each of which
	have the following format:		have the following format:
	Range Size: 3 octet value indicating the number of labels in		Range Size: 3 octet value indicating the number of labels in
	the range.		the range.
	SID/Label TLV (as defined in Section 2.1.1) used as sub-TLV		SID/Label TLV (as defined in Section 2.1.1) used as sub-TLV
	which encodes the first label in the sub-range. Since the SID/		which encodes the first label in the sub-range. Since the SID/
	Label TLV is used to indicate the first label of the SRLB sub-		Label TLV is used to indicate the first label of the SRLB sub-
	range, only label encoding is valid under the SR Local Block		range, only label encoding is valid under the SR Local Block
	TLV.		TLV.
	2.1.5. SRMS Preference TLV		2.1.5. SRMS Preference TLV
	The Segment Routing Mapping Server (SRMS) Preference TLV is used in		The Segment Routing Mapping Server (SRMS) Preference TLV is used in
	order to associate a preference with SRMS advertisements from a		order to associate a preference with SRMS advertisements from a
	particular source. [I-D.ietf-spring-segment-routing-ldp-interop]		particular source. [RFC8661] specifies the SRMS functionality along
	specifies the SRMS functionality along with SRMS preference of the		with SRMS preference of the node advertising the SRMS Prefix-to-SID
	node advertising the SRMS Prefix-to-SID Mapping ranges.		Mapping ranges.
	This information is derived from the protocol specific		This information is derived from the protocol specific
	advertisements.		advertisements.
	o IS-IS, as defined by the SRMS Preference sub-TLV in section 3.4 of		o IS-IS, as defined by the SRMS Preference sub-TLV in section 3.4 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in section		o OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in section
	3.4 of [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3		3.4 of [RFC8665]. OSPFv3 leverages the same TLV as defined for
	leverages the same TLV as defined for OSPFv2.		OSPFv2.
	The SRMS Preference TLV has the following format:		The SRMS Preference TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Preference |		| Preference |
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	skipping to change at page 11, line 29 ¶		skipping to change at page 11, line 27 ¶
	Table 2: Link Attribute TLVs		Table 2: Link Attribute TLVs
	These TLVs should only be added to the BGP-LS Attribute associated		These TLVs should only be added to the BGP-LS Attribute associated
	with the Link NLRI describing the link of the IGP node that is		with the Link NLRI describing the link of the IGP node that is
	originating the corresponding IGP TLV/sub-TLV described below.		originating the corresponding IGP TLV/sub-TLV described below.
	2.2.1. Adjacency SID TLV		2.2.1. Adjacency SID TLV
	The Adjacency SID TLV is used in order to advertise information		The Adjacency SID TLV is used in order to advertise information
	related to an Adjacency SID. This information is derived from Adj-		related to an Adjacency SID. This information is derived from Adj-
	SID sub-TLV of IS-IS (section 2.2.1 of		SID sub-TLV of IS-IS (section 2.2.1 of [RFC8667]), OSPFv2 (section
	[I-D.ietf-isis-segment-routing-extensions]), OSPFv2 (section 6.1 of		6.1 of [RFC8665]) and OSPFv3 (section 7.1 of [RFC8666]).
	[I-D.ietf-ospf-segment-routing-extensions]) and OSPFv3 (section 7.1
	of [I-D.ietf-ospf-ospfv3-segment-routing-extensions]).
	The Adjacency SID TLV has the following format:		The Adjacency SID TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Weight | Reserved |		| Flags | Weight | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 12, line 4 ¶		skipping to change at page 11, line 47 ¶
	| Flags | Weight | Reserved |		| Flags | Weight | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label/Index (variable) //		| SID/Label/Index (variable) //
	+---------------------------------------------------------------+		+---------------------------------------------------------------+
	Figure 7: Adjacency SID TLV Format		Figure 7: Adjacency SID TLV Format
	Where:		Where:
	Type: 1099		Type: 1099
	Length: Variable. Either 7 or 8 depending on Label or Index		Length: Variable. Either 7 or 8 depending on Label or Index
	encoding of the SID		encoding of the SID
	Flags. 1 octet value which should be set as:		Flags. 1 octet value which should be set as:
	* IS-IS Adj-SID flags are defined in section 2.2.1 of		* IS-IS Adj-SID flags are defined in section 2.2.1 of [RFC8667].
	[I-D.ietf-isis-segment-routing-extensions].
	* OSPFv2 Adj-SID flags are defined in section 6.1 of		* OSPFv2 Adj-SID flags are defined in section 6.1 of [RFC8665].
	[I-D.ietf-ospf-segment-routing-extensions].
	* OSPFv3 Adj-SID flags are defined in section 7.1 of		* OSPFv3 Adj-SID flags are defined in section 7.1 of [RFC8666].
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
	Weight: 1 octet carrying the weight used for load-balancing		Weight: 1 octet carrying the weight used for load-balancing
	purposes. The use of weight is described in section 3.4 of		purposes. The use of weight is described in section 3.4 of
	[RFC8402].		[RFC8402].
	Reserved: 2 octets that MUST be set to 0 and ignored on receipt.		Reserved: 2 octets that MUST be set to 0 and ignored on receipt.
	SID/Index/Label:		SID/Index/Label:
	* IS-IS: Label or index value as defined in section 2.2.1 of		* IS-IS: Label or index value as defined in section 2.2.1 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	* OSPFv2: Label or index value as defined in section 6.1 of		* OSPFv2: Label or index value as defined in section 6.1 of
	[I-D.ietf-ospf-segment-routing-extensions].		[RFC8665].
	* OSPFv3: Label or index value as defined in section 7.1 of		* OSPFv3: Label or index value as defined in section 7.1 of
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions].		[RFC8666].
	The Flags and, as an extension, the SID/Index/Label fields of this		The Flags and, as an extension, the SID/Index/Label fields of this
	TLV are interpreted according to the respective underlying IS-IS,		TLV are interpreted according to the respective underlying IS-IS,
	OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Link NLRI		OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Link NLRI
	is used to determine the underlying protocol specification for		is used to determine the underlying protocol specification for
	parsing these fields.		parsing these fields.
	2.2.2. LAN Adjacency SID TLV		2.2.2. LAN Adjacency SID TLV
	For a LAN, normally a node only announces its adjacency to the IS-IS		For a LAN, normally a node only announces its adjacency to the IS-IS
	pseudo-node (or the equivalent OSPF Designated and Backup Designated		pseudo-node (or the equivalent OSPF Designated and Backup Designated
	Routers). The LAN Adjacency Segment TLV allows a node to announce		Routers). The LAN Adjacency Segment TLV allows a node to announce
	adjacencies to all other nodes attached to the LAN in a single		adjacencies to all other nodes attached to the LAN in a single
	instance of the BGP-LS Link NLRI. Without this TLV, the		instance of the BGP-LS Link NLRI. Without this TLV, the
	corresponding BGP-LS link NLRI would need to be originated for each		corresponding BGP-LS link NLRI would need to be originated for each
	additional adjacency in order to advertise the SR TLVs for these		additional adjacency in order to advertise the SR TLVs for these
	neighbor adjacencies.		neighbor adjacencies.
	This information is derived from LAN-Adj-SID sub-TLV of IS-IS		This information is derived from LAN-Adj-SID sub-TLV of IS-IS
	(section 2.2.2 of [I-D.ietf-isis-segment-routing-extensions]) and LAN		(section 2.2.2 of [RFC8667]) and LAN Adj-SID sub-TLV of OSPFv2
	Adj-SID sub-TLV of OSPFv2 (section 6.2 of		(section 6.2 of [RFC8665]) and OSPFv3 (section 7.2 of [RFC8666]).
	[I-D.ietf-ospf-segment-routing-extensions]) and OSPFv3 (section 7.2
	of [I-D.ietf-ospf-ospfv3-segment-routing-extensions]).
	The LAN Adjacency SID TLV has the following format:		The LAN Adjacency SID TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Weight | Reserved |		| Flags | Weight | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 13, line 44 ¶		skipping to change at page 13, line 36 ¶
	Type: 1100		Type: 1100
	Length: Variable. For IS-IS it would be 13 or 14 depending on		Length: Variable. For IS-IS it would be 13 or 14 depending on
	Label or Index encoding of the SID. For OSPF it would be 11 or 12		Label or Index encoding of the SID. For OSPF it would be 11 or 12
	depending on Label or Index encoding of the SID.		depending on Label or Index encoding of the SID.
	Flags. 1 octet value which should be set as:		Flags. 1 octet value which should be set as:
	* IS-IS LAN Adj-SID flags are defined in section 2.2.2 of		* IS-IS LAN Adj-SID flags are defined in section 2.2.2 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	* OSPFv2 LAN Adj-SID flags are defined in section 6.2 of		* OSPFv2 LAN Adj-SID flags are defined in section 6.2 of
	[I-D.ietf-ospf-segment-routing-extensions].		[RFC8665].
	* OSPFv3 LAN Adj-SID flags are defined in section 7.2 of		* OSPFv3 LAN Adj-SID flags are defined in section 7.2 of
	[I-D.ietf-ospf-segment-routing-extensions].		[RFC8666].
	Weight: 1 octet carrying the weight used for load-balancing		Weight: 1 octet carrying the weight used for load-balancing
	purposes. The use of weight is described in section 3.4 of		purposes. The use of weight is described in section 3.4 of
	[RFC8402].		[RFC8402].
	Reserved: 2 octets that MUST be set to 0 and ignored on receipt.		Reserved: 2 octets that MUST be set to 0 and ignored on receipt.
	Neighbor ID: 6 octets for IS-IS for the System-ID and 4 octets for		Neighbor ID: 6 octets for IS-IS for the System-ID and 4 octets for
	OSPF for the OSPF Router-ID of the neighbor.		OSPF for the OSPF Router-ID of the neighbor.
	SID/Index/Label:		SID/Index/Label:
	* IS-IS: Label or index value as defined in section 2.2.2 of		* IS-IS: Label or index value as defined in section 2.2.2 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	* OSPFv2: Label or index value as defined in section 6.2 of		* OSPFv2: Label or index value as defined in section 6.2 of
	[I-D.ietf-ospf-segment-routing-extensions].		[RFC8665].
	* OSPFv3: Label or index value as defined in section 7.2 of		* OSPFv3: Label or index value as defined in section 7.2 of
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions].		[RFC8666].
	The Neighbor ID, Flags and, as an extension, the SID/Index/Label		The Neighbor ID, Flags and, as an extension, the SID/Index/Label
	fields of this TLV are interpreted according to the respective		fields of this TLV are interpreted according to the respective
	underlying IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the		underlying IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the
	BGP-LS Link NLRI is used to determine the underlying protocol		BGP-LS Link NLRI is used to determine the underlying protocol
	specification for parsing these fields.		specification for parsing these fields.
	2.2.3. L2 Bundle Member Attribute TLV		2.2.3. L2 Bundle Member Attribute TLV
	The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member		The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member
	link which in turn is associated with a parent L3 link. The L3 link		link which in turn is associated with a parent L3 link. The L3 link
	is described by the Link NLRI defined in [RFC7752] and the L2 Bundle		is described by the Link NLRI defined in [RFC7752] and the L2 Bundle
	Member Attribute TLV is associated with the Link NLRI. The TLV MAY		Member Attribute TLV is associated with the Link NLRI. The TLV MAY
	include sub-TLVs which describe attributes associated with the bundle		include sub-TLVs which describe attributes associated with the bundle
	member. The identified bundle member represents a unidirectional		member. The identified bundle member represents a unidirectional
	path from the originating router to the neighbor specified in the		path from the originating router to the neighbor specified in the
	parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be		parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be
	associated with a Link NLRI.		associated with a Link NLRI.
	This information is derived from L2 Bundle Member Attributes TLV of		This information is derived from L2 Bundle Member Attributes TLV of
	IS-IS (section 2 of [I-D.ietf-isis-l2bundles]). The equivalent		IS-IS (section 2 of [RFC8668]). The equivalent functionality has not
	functionality has not been specified as yet for OSPF.		been specified as yet for OSPF.
	The L2 Bundle Member Attribute TLV has the following format:		The L2 Bundle Member Attribute TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| L2 Bundle Member Descriptor |		| L2 Bundle Member Descriptor |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 16, line 36 ¶		skipping to change at page 16, line 5 ¶
	| | utilization | |		| | utilization | |
	+-------------+------------------------------------+----------------+		+-------------+------------------------------------+----------------+
	Table 3: BGP-LS Attribute TLVs also used as sub-TLVs of L2 Bundle		Table 3: BGP-LS Attribute TLVs also used as sub-TLVs of L2 Bundle
	Member Attribute TLV		Member Attribute TLV
	2.3. Prefix Attribute TLVs		2.3. Prefix Attribute TLVs
	The following Prefix Attribute TLVs are defined:		The following Prefix Attribute TLVs are defined:
	+------+------------------------+---------------+		+------------------+--------------------------+---------------+
	| Type | Description | Section |		| Type | Description | Section |
	+------+------------------------+---------------+		+------------------+--------------------------+---------------+
	| 1158 | Prefix SID | Section 2.3.1 |		| 1158 | Prefix SID | Section 2.3.1 |
	| 1159 | Range | Section 2.3.4 |		| 1159 | Range | Section 2.3.5 |
	| 1170 | Prefix Attribute Flags | Section 2.3.2 |		| 1170 | Prefix Attribute Flags | Section 2.3.2 |
	| 1171 | Source Router-ID | Section 2.3.3 |		| 1171 | Source Router Identifier | Section 2.3.3 |
	+------+------------------------+---------------+		| 1174 (suggested) | Source OSPF Router-ID | Section 2.3.4 |
			+------------------+--------------------------+---------------+
	Table 4: Prefix Attribute TLVs		Table 4: Prefix Attribute TLVs
	These TLVs should only be added to the BGP-LS Attribute associated		These TLVs should only be added to the BGP-LS Attribute associated
	with the Prefix NLRI describing the prefix of the IGP node that is		with the Prefix NLRI describing the prefix of the IGP node that is
	originating the corresponding IGP TLV/sub-TLV described below.		originating the corresponding IGP TLV/sub-TLV described below.
	2.3.1. Prefix SID TLV		2.3.1. Prefix SID TLV
	The Prefix SID TLV is used in order to advertise information related		The Prefix SID TLV is used in order to advertise information related
	to a Prefix SID. This information is derived from Prefix-SID sub-TLV		to a Prefix SID. This information is derived from Prefix-SID sub-TLV
	of IS-IS (section 2.1 of [I-D.ietf-isis-segment-routing-extensions])		of IS-IS (section 2.1 of [RFC8667]) and the Prefix SID sub-TLV of
	and the Prefix SID sub-TLV of OSPFv2 (section 5 of		OSPFv2 (section 5 of [RFC8665]) and OSPFv3 (section 6 of [RFC8666]).
	[I-D.ietf-ospf-segment-routing-extensions]) and OSPFv3 (section 6 of
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]).
	The Prefix SID TLV has the following format:		The Prefix SID TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Algorithm | Reserved |		| Flags | Algorithm | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 17, line 38 ¶		skipping to change at page 17, line 6 ¶
	Where:		Where:
	Type: 1158		Type: 1158
	Length: Variable. 7 or 8 depending on Label or Index encoding of		Length: Variable. 7 or 8 depending on Label or Index encoding of
	the SID		the SID
	Flags: 1 octet value which should be set as:		Flags: 1 octet value which should be set as:
	* IS-IS Prefix SID flags are defined in section 2.1.1 of		* IS-IS Prefix SID flags are defined in section 2.1.1 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	* OSPFv2 Prefix SID flags are defined in section 5 of		* OSPFv2 Prefix SID flags are defined in section 5 of [RFC8665].
	[I-D.ietf-ospf-segment-routing-extensions].
	* OSPFv3 Prefix SID flags are defined in section 6 of		* OSPFv3 Prefix SID flags are defined in section 6 of [RFC8666].
	[I-D.ietf-ospf-segment-routing-extensions].
	Algorithm: 1 octet value identify the algorithm. The semantics of		Algorithm: 1 octet value identify the algorithm. The semantics of
	algorithm are described in section 3.1.1 of [RFC8402].		algorithm are described in section 3.1.1 of [RFC8402].
	Reserved: 2 octets that MUST be set to 0 and ignored on receipt.		Reserved: 2 octets that MUST be set to 0 and ignored on receipt.
	SID/Index/Label:		SID/Index/Label:
	* IS-IS: Label or index value as defined in section 2.1 of		* IS-IS: Label or index value as defined in section 2.1 of
	[I-D.ietf-isis-segment-routing-extensions].		[RFC8667].
	* OSPFv2: Label or index value as defined in section 5 of		* OSPFv2: Label or index value as defined in section 5 of
	[I-D.ietf-ospf-segment-routing-extensions].		[RFC8665].
	* OSPFv3: Label or index value as defined in section 6 of		* OSPFv3: Label or index value as defined in section 6 of
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions].		[RFC8666].
	The Flags and, as an extension, the SID/Index/Label fields of this		The Flags and, as an extension, the SID/Index/Label fields of this
	TLV are interpreted according to the respective underlying IS-IS,		TLV are interpreted according to the respective underlying IS-IS,
	OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Prefix NLRI		OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Prefix NLRI
	is used to determine the underlying protocol specification for		is used to determine the underlying protocol specification for
	parsing these fields.		parsing these fields.
	2.3.2. Prefix Attribute Flags TLV		2.3.2. Prefix Attribute Flags TLV
	The Prefix Attribute Flags TLV carries IPv4/IPv6 prefix attribute		The Prefix Attribute Flags TLV carries IPv4/IPv6 prefix attribute
	skipping to change at page 18, line 50 ¶		skipping to change at page 18, line 16 ¶
	Type: 1170		Type: 1170
	Length: Variable.		Length: Variable.
	Flags: a variable length flag field (according to the length		Flags: a variable length flag field (according to the length
	field). Flags are routing protocol specific and are to be set as		field). Flags are routing protocol specific and are to be set as
	below:		below:
	* IS-IS flags correspond to the IPv4/IPv6 Extended Reachability		* IS-IS flags correspond to the IPv4/IPv6 Extended Reachability
	Attribute Flags defined in section 2.1 of [RFC7794]		Attribute Flags defined in section 2.1 of [RFC7794]. In the
			case of the X-flag when associated with IPv6 prefix
			reachability, the setting corresponds to the setting of the
			X-flag in the fixed format of IS-IS TLVs 236 [RFC5308] and 237
			[RFC5120].
	* OSPFv2 flags correspond to the Flags field of the OSPFv2		* OSPFv2 flags correspond to the Flags field of the OSPFv2
	Extended Prefix TLV defined in section 2.1 of [RFC7684]		Extended Prefix TLV defined in section 2.1 of [RFC7684]
	* OSPFv3 flags map to the Prefix Options field defined in section		* OSPFv3 flags map to the Prefix Options field defined in section
	A.4.1.1 of [RFC5340] and extended in section 3.1 of [RFC8362]		A.4.1.1 of [RFC5340] and extended in section 3.1 of [RFC8362]
	The Flags field of this TLV is interpreted according to the		The Flags field of this TLV is interpreted according to the
	respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The		respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The
	Protocol-ID of the BGP-LS Prefix NLRI is used to determine the		Protocol-ID of the BGP-LS Prefix NLRI is used to determine the
	underlying protocol specification for parsing this field.		underlying protocol specification for parsing this field.
	2.3.3. Source Router Identifier (Source Router-ID) TLV		2.3.3. Source Router Identifier TLV
	The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the		The Source Router Identifier TLV contains the IPv4 or IPv6 Router
	originator of the Prefix. For the IS-IS protocol this is derived		Identifier of the originator of the Prefix. For the IS-IS protocol
	from the IPv4/IPv6 Source Router ID sub-TLV as defined in section 2.2		this is derived from the IPv4/IPv6 Source Router ID sub-TLV as
	of [RFC7794]. For the OSPF protocol, this is derived from the Prefix		defined in section 2.2 of [RFC7794]. For the OSPF protocol, this is
	Source Router-ID sub-TLV as defined in section 4 of		derived from the Prefix Source Router Address sub-TLV as defined in
	[I-D.ietf-lsr-ospf-prefix-originator].		section 2.2 of [I-D.ietf-lsr-ospf-prefix-originator].
	The Source Router-ID TLV has the following format:		The Source Router Identifier TLV has the following format:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| 4 or 16 octet Router-ID //		| 4 or 16 octet Router Identifier //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 12: Source Router-ID TLV Format		Figure 12: Source Router Identifier TLV Format
	Where:		Where:
	Type: 1171		Type: 1171
	Length: Variable. 4 or 16 in case of IS-IS and 4 in case of OSPF.		Length: Variable. 4 or 16 for IPv4 and IPv6 prefix respectively.
	Router-ID: the IPv4 or IPv6 Router-ID in case of IS-IS and the		Router-ID: the IPv4 or IPv6 Router-ID in case of IS-IS and the
	OSPF Router-ID in the case of OSPF.		IPv4 or IPv6 Router Address in the case of OSPF.
	2.3.4. Range TLV		2.3.4. Source OSPF Router-ID TLV
			The Source OSPF Router-ID TLV is applicable only for the OSPF
			protocol and contains OSPF Router-ID of the originator of the Prefix.
			It is derived from the Prefix Source OSPF Router-ID sub-TLV as
			defined in section 2.1 of [I-D.ietf-lsr-ospf-prefix-originator].
			The Source OSPF Router-ID TLV 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 |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| 4 octet OSPF Router-ID //
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			Figure 13: Source OSPF Router-ID TLV Format
			Where:
			Type: 1174 (suggested)
			Length: 4
			OSPF Router-ID: the OSPF Router-ID of the node originating the
			prefix.
			2.3.5. Range TLV
	The Range TLV is used in order to advertise a range of prefix-to-SID		The Range TLV is used in order to advertise a range of prefix-to-SID
	mappings as part of the Segment Routing Mapping Server (SRMS)		mappings as part of the Segment Routing Mapping Server (SRMS)
	functionality [I-D.ietf-spring-segment-routing-ldp-interop], as		functionality [RFC8661], as defined in the respective underlying IGP
	defined in the respective underlying IGP SR extensions		SR extensions [RFC8665] (section 4), [RFC8666] (section 5) and
			[RFC8667] (section 2.4). The information advertised in the Range TLV
	[I-D.ietf-ospf-segment-routing-extensions] (section 4),		is derived from the SID/Label Binding TLV in the case of IS-IS and
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions] (section 5) and		the OSPFv2/OSPFv3 Extended Prefix Range TLV in the case of OSPFv2/
	[I-D.ietf-isis-segment-routing-extensions] (section 2.4). The		OSPFv3.
	information advertised in the Range TLV is derived from the SID/Label
	Binding TLV in the case of IS-IS and the OSPFv2/OSPFv3 Extended
	Prefix Range TLV in the case of OSPFv2/OSPFv3.
	A Prefix NLRI, that been advertised with a Range TLV, is considered a		A Prefix NLRI, that been advertised with a Range TLV, is considered a
	normal routing prefix (i.e. prefix reachability) only when there is		normal routing prefix (i.e. prefix reachability) only when there is
	also an IGP metric TLV (TLV 1095) associated it. Otherwise, it is		also an IGP metric TLV (TLV 1095) associated it. Otherwise, it is
	considered only as the first prefix in the range for prefix-to-SID		considered only as the first prefix in the range for prefix-to-SID
	mapping advertisement.		mapping advertisement.
	The format of the Range TLV is as follows:		The format of the Range TLV is as follows:
	0 1 2 3		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		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 |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Flags | Reserved | Range Size |		| Flags | Reserved | Range Size |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| sub-TLVs //		| sub-TLVs //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 13: Range TLV Format		Figure 14: Range TLV Format
	Where:		Where:
	Type: 1159		Type: 1159
	Length: Variable. 11 or 12 depending on Label or Index encoding of		Length: Variable. 11 or 12 depending on Label or Index encoding of
	the SID		the SID
	Flags: 1 octet value which should be set as:		Flags: 1 octet value which should be set as:
	* IS-IS SID/Label Binding TLV flags are defined in section 2.4.1		* IS-IS SID/Label Binding TLV flags are defined in section 2.4.1
	of [I-D.ietf-isis-segment-routing-extensions].		of [RFC8667].
	* OSPFv2 OSPF Extended Prefix Range TLV flags are defined in		* OSPFv2 OSPF Extended Prefix Range TLV flags are defined in
	section 4 of [I-D.ietf-ospf-segment-routing-extensions].		section 4 of [RFC8665].
	* OSPFv3 Extended Prefix Range TLV flags are defined in section 5		* OSPFv3 Extended Prefix Range TLV flags are defined in section 5
	of [I-D.ietf-ospf-ospfv3-segment-routing-extensions].		of [RFC8666].
	Reserved: 1 octet that MUST be set to 0 and ignored on receipt.		Reserved: 1 octet that MUST be set to 0 and ignored on receipt.
	Range Size: 2 octets that carry the number of prefixes that are		Range Size: 2 octets that carry the number of prefixes that are
	covered by the advertisement..		covered by the advertisement..
	The Flags field of this TLV is interpreted according to the		The Flags field of this TLV is interpreted according to the
	respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The		respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The
	Protocol-ID of the BGP-LS Prefix NLRI is used to determine the		Protocol-ID of the BGP-LS Prefix NLRI is used to determine the
	underlying protocol specification for parsing this field.		underlying protocol specification for parsing this field.
	skipping to change at page 22, line 5 ¶		skipping to change at page 22, line 5 ¶
	Section 2.3.1.		Section 2.3.1.
	2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs		2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs
	This section illustrate the IS-IS Segment Routing Extensions TLVs and		This section illustrate the IS-IS Segment Routing Extensions TLVs and
	sub-TLVs mapped to the ones defined in this document.		sub-TLVs mapped to the ones defined in this document.
	The following table, illustrates for each BGP-LS TLV, its equivalence		The following table, illustrates for each BGP-LS TLV, its equivalence
	in IS-IS.		in IS-IS.
	+------------+---------------+--------------------------------------+		+----------------------+--------------------------------+-----------+
	| Descriptio | IS-IS TLV | Reference |		| Description | IS-IS TLV/sub-TLV | Reference |
	| n | /sub-TLV | |		+----------------------+--------------------------------+-----------+
	+------------+---------------+--------------------------------------+		| SR Capabilities | SR-Capabilities sub-TLV (2) | [RFC8667] |
	| SR Capabil | SR- | [I-D.ietf-isis-segment-routing-exten |		| SR Algorithm | SR-Algorithm sub-TLV (19) | [RFC8667] |
	| ities | Capabilities | sions] |		| SR Local Block | SR Local Block sub-TLV (22) | [RFC8667] |
	| | sub-TLV (2) | |		| SRMS Preference | SRMS Preference sub-TLV (19) | [RFC8667] |
	| SR | SR-Algorithm | [I-D.ietf-isis-segment-routing-exten |		| Adjacency SID | Adj-SID sub-TLV (31) | [RFC8667] |
	| Algorithm | sub-TLV (19) | sions] |		| LAN Adjacency SID | LAN-Adj-SID sub-TLV (32) | [RFC8667] |
	| SR Local | SR Local | [I-D.ietf-isis-segment-routing-exten |		| Prefix SID | Prefix-SID sub-TLV (3) | [RFC8667] |
	| Block | Block sub-TLV | sions] |		| Range | SID/Label Binding TLV (149) | [RFC8667] |
	| | (22) | |		| SID/Label | SID/Label sub-TLV (1) | [RFC8667] |
	| SRMS | SRMS | [I-D.ietf-isis-segment-routing-exten |		| Prefix Attribute | Prefix Attributes Flags sub- | [RFC7794] |
	| Preference | Preference | sions] |		| Flags | TLV (4) | |
	| | sub-TLV (19) | |		| Source Router | IPv4/IPv6 Source Router ID | [RFC7794] |
	| Adjacency | Adj-SID sub- | [I-D.ietf-isis-segment-routing-exten |		| Identifier | sub-TLV (11/12) | |
	| SID | TLV (31) | sions] |		| L2 Bundle Member | L2 Bundle Member Attributes | [RFC8668] |
	| LAN | LAN-Adj-SID | [I-D.ietf-isis-segment-routing-exten |		| Attributes | TLV (25) | |
	| Adjacency | sub-TLV (32) | sions] |		+----------------------+--------------------------------+-----------+
	| SID | | |
	| Prefix SID | Prefix-SID | [I-D.ietf-isis-segment-routing-exten |
	| | sub-TLV (3) | sions] |
	| Range | SID/Label | [I-D.ietf-isis-segment-routing-exten |
	| | Binding TLV | sions] |
	| | (149) | |
	| SID/Label | SID/Label | [I-D.ietf-isis-segment-routing-exten |
	| | sub-TLV (1) | sions] |
	| Prefix | Prefix | [RFC7794] |
	| Attribute | Attributes | |
	| Flags | Flags sub-TLV | |
	| | (4) | |
	| Source | IPv4/IPv6 | [RFC7794] |
	| Router-ID | Source Router | |
	| | ID sub-TLV | |
	| | (11/12) | |
	| L2 Bundle | L2 Bundle | [I-D.ietf-isis-l2bundles] |
	| Member | Member | |
	| Attributes | Attributes | |
	| | TLV (25) | |
	+------------+---------------+--------------------------------------+
	Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs		Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs
	2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs		2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs
	This section illustrate the OSPFv2 and OSPFv3 Segment Routing		This section illustrate the OSPFv2 and OSPFv3 Segment Routing
	Extensions TLVs and sub-TLVs mapped to the ones defined in this		Extensions TLVs and sub-TLVs mapped to the ones defined in this
	document.		document.
	The following table, illustrates for each BGP-LS TLV, its equivalence		The following table, illustrates for each BGP-LS TLV, its equivalence
	in OSPFv2 and OSPFv3.		in OSPFv2 and OSPFv3.
	+------------+-------------+----------------------------------------+		+-------------+--------------+--------------------------------------+
	| Descriptio | OSPFv2 TLV | Reference |		| Description | OSPFv2 | Reference |
	| n | /sub-TLV | |		| | TLV/sub-TLV | |
	+------------+-------------+----------------------------------------+		+-------------+--------------+--------------------------------------+
	| SR Capabil | SID/Label | [I-D.ietf-ospf-segment-routing-extensi |		| SR Capabili | SID/Label | [RFC8665] |
	| ities | Range TLV | ons] |		| ties | Range TLV | |
	| | (9) | |		| | (9) | |
	| SR | SR- | [I-D.ietf-ospf-segment-routing-extensi |		| SR | SR-Algorithm | [RFC8665] |
	| Algorithm | Algorithm | ons] |		| Algorithm | TLV (8) | |
	| | TLV (8) | |		| SR Local | SR Local | [RFC8665] |
	| SR Local | SR Local | [I-D.ietf-ospf-segment-routing-extensi |		| Block | Block TLV | |
	| Block | Block TLV | ons] |		| | (14) | |
	| | (14) | |		| SRMS | SRMS | [RFC8665] |
	| SRMS | SRMS | [I-D.ietf-ospf-segment-routing-extensi |		| Preference | Preference | |
	| Preference | Preference | ons] |		| | TLV (15) | |
	| | TLV (15) | |		| Adjacency | Adj-SID sub- | [RFC8665] |
	| Adjacency | Adj-SID | [I-D.ietf-ospf-segment-routing-extensi |		| SID | TLV (2) | |
	| SID | sub-TLV (2) | ons] |		| LAN | LAN Adj-SID | [RFC8665] |
	| LAN | LAN Adj-SID | [I-D.ietf-ospf-segment-routing-extensi |		| Adjacency | sub-TLV (3) | |
	| Adjacency | sub-TLV (3) | ons] |		| SID | | |
	| SID | | |		| Prefix SID | Prefix SID | [RFC8665] |
	| Prefix SID | Prefix SID | [I-D.ietf-ospf-segment-routing-extensi |		| | sub-TLV (2) | |
	| | sub-TLV (2) | ons] |		| Range | OSPF | [RFC8665] |
	| Range | OSPF | [I-D.ietf-ospf-segment-routing-extensi |		| | Extended | |
	| | Extended | ons] |		| | Prefix Range | |
	| | Prefix | |		| | TLV (2) | |
	| | Range TLV | |		| SID/Label | SID/Label | [RFC8665] |
	| | (2) | |		| | sub-TLV (1) | |
	| SID/Label | SID/Label | [I-D.ietf-ospf-segment-routing-extensi |		| Prefix | Flags of | [RFC7684] |
	| | sub-TLV (1) | ons] |		| Attribute | OSPFv2 | |
	| Prefix | Flags of | [RFC7684] |		| Flags | Extended | |
	| Attribute | OSPFv2 | |		| | Prefix TLV | |
	| Flags | Extended | |		| | (1) | |
	| | Prefix TLV | |		| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| | (1) | |		| Router | Source | ] |
	| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator] |		| Identifier | Router-ID | |
	| Router-ID | Source | |		| | sub-TLV (4) | |
	| | Router-ID | |		| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| | sub-TLV | |		| Router-ID | Source OSPF | ] |
	| | (TBD) | |		| | Router-ID | |
	+------------+-------------+----------------------------------------+		| | sub-TLV (5) | |
			+-------------+--------------+--------------------------------------+
	Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs		Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs
	+-----------+------------+------------------------------------------+		+-------------+--------------+--------------------------------------+
	| Descripti | OSPFv3 TLV | Reference |		| Description | OSPFv3 | Reference |
	| on | /sub-TLV | |		| | TLV/sub-TLV | |
	+-----------+------------+------------------------------------------+		+-------------+--------------+--------------------------------------+
	| SR Capabi | SID/Label | [I-D.ietf-ospf-segment-routing-extension |		| SR Capabili | SID/Label | [RFC8665] |
	| lities | Range TLV | s] |		| ties | Range TLV | |
	| | (9) | |		| | (9) | |
	| SR | SR- | [I-D.ietf-ospf-segment-routing-extension |		| SR | SR-Algorithm | [RFC8665] |
	| Algorithm | Algorithm | s] |		| Algorithm | TLV (8) | |
	| | TLV (8) | |		| SR Local | SR Local | [RFC8665] |
	| SR Local | SR Local | [I-D.ietf-ospf-segment-routing-extension |		| Block | Block TLV | |
	| Block | Block TLV | s] |		| | (14) | |
	| | (14) | |		| SRMS | SRMS | [RFC8665] |
	| SRMS Pref | SRMS | [I-D.ietf-ospf-segment-routing-extension |		| Preference | Preference | |
	| erence | Preference | s] |		| | TLV (15) | |
	| | TLV (15) | |		| Adjacency | Adj-SID sub- | [RFC8666] |
	| Adjacency | Adj-SID | [I-D.ietf-ospf-ospfv3-segment-routing-ex |		| SID | TLV (5) | |
	| SID | sub-TLV | tensions] |		| LAN | LAN Adj-SID | [RFC8666] |
	| | (5) | |		| Adjacency | sub-TLV (6) | |
	| LAN | LAN Adj- | [I-D.ietf-ospf-ospfv3-segment-routing-ex |		| SID | | |
	| Adjacency | SID sub- | tensions] |		| Prefix SID | Prefix SID | [RFC8666] |
	| SID | TLV (6) | |		| | sub-TLV (4) | |
	| Prefix | Prefix SID | [I-D.ietf-ospf-ospfv3-segment-routing-ex |		| Range | OSPFv3 | [RFC8666] |
	| SID | sub-TLV | tensions] |		| | Extended | |
	| | (4) | |		| | Prefix Range | |
	| Range | OSPFv3 | [I-D.ietf-ospf-ospfv3-segment-routing-ex |		| | TLV (9) | |
	| | Extended | tensions] |		| SID/Label | SID/Label | [RFC8666] |
	| | Prefix | |		| | sub-TLV (7) | |
	| | Range TLV | |		| Prefix | Prefix | [RFC8362] |
	| | (9) | |		| Attribute | Option | |
	| SID/Label | SID/Label | [I-D.ietf-ospf-ospfv3-segment-routing-ex |		| Flags | Fields of | |
	| | sub-TLV | tensions] |		| | Prefix TLV | |
	| | (7) | |		| | types 3,5,6 | |
	| Prefix | Prefix | [RFC8362] |		| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| Attribute | Option | |		| Router | Source | ] |
	| Flags | Fields of | |		| Identifier | Router-ID | |
	| | Prefix TLV | |		| | sub-TLV (27) | |
	| | types | |		| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| | 3,5,6 | |		| Router-ID | Source OSPF | ] |
	| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator] |		| | Router-ID | |
	| Router-ID | Source | |		| | sub-TLV (28) | |
	| | Router-ID | |		+-------------+--------------+--------------------------------------+
	| | sub-TLV | |
	| | (TBD) | |
	+-----------+------------+------------------------------------------+
	Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs		Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs
	3. IANA Considerations		3. IANA Considerations
	Early allocation of codepoints has been done by IANA for this		Early allocation of codepoints has been done by IANA for this
	document from the registry "BGP-LS Node Descriptor, Link Descriptor,		document from the registry "BGP-LS Node Descriptor, Link Descriptor,
	Prefix Descriptor, and Attribute TLVs" under the "BGP-LS Parameters"		Prefix Descriptor, and Attribute TLVs" under the "BGP-LS Parameters"
	registry based on Table 8. The column "IS-IS TLV/Sub-TLV" defined in		registry based on Table 8. The column "IS-IS TLV/Sub-TLV" defined in
	the registry does not require any value and should be left empty.		the registry does not require any value and should be left empty.
	3.1. TLV/Sub-TLV Code Points Summary		3.1. TLV/Sub-TLV Code Points Summary
	This section contains the global table of all TLVs/sub-TLVs defined		This section contains the global table of all TLVs/sub-TLVs defined
	in this document.		in this document.
	+----------------+-----------------------------+---------------+		+------------------+-----------------------------+---------------+
	| TLV Code Point | Description | Reference |		| TLV Code Point | Description | Reference |
	+----------------+-----------------------------+---------------+		+------------------+-----------------------------+---------------+
	| 1034 | SR Capabilities | Section 2.1.2 |		| 1034 | SR Capabilities | Section 2.1.2 |
	| 1035 | SR Algorithm | Section 2.1.3 |		| 1035 | SR Algorithm | Section 2.1.3 |
	| 1036 | SR Local Block | Section 2.1.4 |		| 1036 | SR Local Block | Section 2.1.4 |
	| 1037 | SRMS Preference | Section 2.1.5 |		| 1037 | SRMS Preference | Section 2.1.5 |
	| 1099 | Adjacency SID | Section 2.2.1 |		| 1099 | Adjacency SID | Section 2.2.1 |
	| 1100 | LAN Adjacency SID | Section 2.2.2 |		| 1100 | LAN Adjacency SID | Section 2.2.2 |
	| 1158 | Prefix SID | Section 2.3.1 |		| 1158 | Prefix SID | Section 2.3.1 |
	| 1159 | Range | Section 2.3.4 |		| 1159 | Range | Section 2.3.5 |
	| 1161 | SID/Label | Section 2.1.1 |		| 1161 | SID/Label | Section 2.1.1 |
	| 1170 | Prefix Attribute Flags | Section 2.3.2 |		| 1170 | Prefix Attribute Flags | Section 2.3.2 |
	| 1171 | Source Router-ID | Section 2.3.3 |		| 1171 | Source Router Identifier | Section 2.3.3 |
	| 1172 | L2 Bundle Member Attributes | Section 2.2.3 |		| 1172 | L2 Bundle Member Attributes | Section 2.2.3 |
	+----------------+-----------------------------+---------------+		| 1174 (suggested) | Source OSPF Router-ID | Section 2.3.4 |
			+------------------+-----------------------------+---------------+
	Table 8: Summary Table of TLV/Sub-TLV Codepoints		Table 8: Summary Table of TLV/Sub-TLV Codepoints
	4. Manageability Considerations		4. Manageability Considerations
	This section is structured as recommended in [RFC5706].		This section is structured as recommended in [RFC5706].
	The new protocol extensions introduced in this document augment the		The new protocol extensions introduced in this document augment the
	existing IGP topology information that is distributed via [RFC7752].		existing IGP topology information that is distributed via [RFC7752].
	Procedures and protocol extensions defined in this document do not		Procedures and protocol extensions defined in this document do not
	skipping to change at page 26, line 12 ¶		skipping to change at page 26, line 14 ¶
	left to the consumer of the BGP-LS information (e.g. an application		left to the consumer of the BGP-LS information (e.g. an application
	or a controller) and not the BGP protocol.		or a controller) and not the BGP protocol.
	A consumer of the BGP-LS information retrieves this information over		A consumer of the BGP-LS information retrieves this information over
	a BGP-LS session (refer Section 1 and 2 of [RFC7752]). The handling		a BGP-LS session (refer Section 1 and 2 of [RFC7752]). The handling
	of semantic or content errors by the consumer would be dictated by		of semantic or content errors by the consumer would be dictated by
	the nature of its application usage and hence is beyond the scope of		the nature of its application usage and hence is beyond the scope of
	this document.		this document.
	This document only introduces new Attribute TLVs and any syntactic		This document only introduces new Attribute TLVs and any syntactic
	error in them would result in only that specific attribute being		error in them would result in the BGP-LS Attribute being discarded
	discarded with an error log. The SR information introduced in BGP-LS		with an error log. The SR information introduced in BGP-LS by this
	by this specification, may be used by BGP-LS consumer applications		specification, may be used by BGP-LS consumer applications like a SR
	like a SR path computation engine (PCE) to learn the SR capabilities		path computation engine (PCE) to learn the SR capabilities of the
	of the nodes in the topology and the mapping of SR segments to those		nodes in the topology and the mapping of SR segments to those nodes.
	nodes. This can enable the SR PCE to perform path computations based		This can enable the SR PCE to perform path computations based on SR
	on SR for traffic engineering use-cases and to steer traffic on paths		for traffic engineering use-cases and to steer traffic on paths
	different from the underlying IGP based distributed best path		different from the underlying IGP based distributed best path
	computation. Errors in the encoding or decoding of the SR		computation. Errors in the encoding or decoding of the SR
	information may result in the unavailability of such information to		information may result in the unavailability of such information to
	the SR PCE or incorrect information being made available to it. This		the SR PCE or incorrect information being made available to it. This
	may result in the SR PCE not being able to perform the desired SR		may result in the SR PCE not being able to perform the desired SR
	based optimization functionality or to perform it in an unexpected or		based optimization functionality or to perform it in an unexpected or
	inconsistent manner. The handling of such errors by applications		inconsistent manner. The handling of such errors by applications
	like SR PCE may be implementation specific and out of scope of this		like SR PCE may be implementation specific and out of scope of this
	document.		document.
	skipping to change at page 26, line 48 ¶		skipping to change at page 26, line 50 ¶
	existing IGP topology information that is distributed via [RFC7752].		existing IGP topology information that is distributed via [RFC7752].
	The advertisement of the SR link attribute information defined in		The advertisement of the SR link attribute information defined in
	this document presents similar risk as associated with the existing		this document presents similar risk as associated with the existing
	set of link attribute information as described in [RFC7752]. The		set of link attribute information as described in [RFC7752]. The
	Security Considerations section of [RFC7752] also applies to these		Security Considerations section of [RFC7752] also applies to these
	extensions. The procedures and new TLVs defined in this document, by		extensions. The procedures and new TLVs defined in this document, by
	themselves, do not affect the BGP-LS security model discussed in		themselves, do not affect the BGP-LS security model discussed in
	[RFC7752].		[RFC7752].
	The TLVs introduced in this document are used to propagate IGP		The TLVs introduced in this document are used to propagate IGP
	defined information ([I-D.ietf-isis-segment-routing-extensions],		defined information ([RFC8667], [RFC8665] and [RFC8666]). These TLVs
	[I-D.ietf-ospf-segment-routing-extensions] and
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]). These TLVs
	represent the SR information associated with the IGP node, link and		represent the SR information associated with the IGP node, link and
	prefix. The IGP instances originating these TLVs are assumed to		prefix. The IGP instances originating these TLVs are assumed to
	support all the required security and authentication mechanisms (as		support all the required security and authentication mechanisms (as
	described in [I-D.ietf-isis-segment-routing-extensions],		described in [RFC8667], [RFC8665] and [RFC8666]) in order to prevent
	[I-D.ietf-ospf-segment-routing-extensions] and		any security issue when propagating the TLVs into BGP-LS.
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]) in order to
	prevent any security issue when propagating the TLVs into BGP-LS.
	BGP-LS SR extensions enable traffic engineering use-cases within the		BGP-LS SR extensions enable traffic engineering use-cases within the
	Segment Routing domain. SR operates within a trusted domain		Segment Routing domain. SR operates within a trusted domain
	[RFC8402] and its security considerations also apply to BGP-LS		[RFC8402] and its security considerations also apply to BGP-LS
	sessions when carrying SR information. The SR traffic engineering		sessions when carrying SR information. The SR traffic engineering
	policies using the SIDs advertised via BGP-LS are expected to be used		policies using the SIDs advertised via BGP-LS are expected to be used
	entirely within this trusted SR domain (e.g. between multiple AS/		entirely within this trusted SR domain (e.g. between multiple AS/
	domains within a single provider network). Therefore, precaution is		domains within a single provider network). Therefore, precaution is
	necessary to ensure that the link-state information (including SR		necessary to ensure that the link-state information (including SR
	information) advertised via BGP-LS sessions is limited to consumers		information) advertised via BGP-LS sessions is limited to consumers
	skipping to change at page 28, line 17 ¶		skipping to change at page 28, line 17 ¶
	The authors would like to thank Jeffrey Haas, Aijun Wang, Robert		The authors would like to thank Jeffrey Haas, Aijun Wang, Robert
	Raszuk and Susan Hares for their review of this document and their		Raszuk and Susan Hares for their review of this document and their
	comments. The authors would also like to thank Alvaro Retana for his		comments. The authors would also like to thank Alvaro Retana for his
	extensive review and comments which helped correct issues and improve		extensive review and comments which helped correct issues and improve
	the document.		the document.
	8. References		8. References
	8.1. Normative References		8.1. Normative References
	[I-D.ietf-isis-l2bundles]
	Ginsberg, L., Bashandy, A., Filsfils, C., Nanduri, M., and
	E. Aries, "Advertising L2 Bundle Member Link Attributes in
	IS-IS", draft-ietf-isis-l2bundles-07 (work in progress),
	May 2017.
	[I-D.ietf-isis-segment-routing-extensions]
	Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A.,
	Gredler, H., and B. Decraene, "IS-IS Extensions for
	Segment Routing", draft-ietf-isis-segment-routing-
	extensions-25 (work in progress), May 2019.
	[I-D.ietf-lsr-ospf-prefix-originator]		[I-D.ietf-lsr-ospf-prefix-originator]
	Wang, A., Lindem, A., Dong, J., Talaulikar, K., and P.		Wang, A., Lindem, A., Dong, J., Psenak, P., and K.
	Psenak, "OSPF Extension for Prefix Originator", draft-		Talaulikar, "OSPF Prefix Originator Extensions", draft-
	ietf-lsr-ospf-prefix-originator-00 (work in progress),		ietf-lsr-ospf-prefix-originator-07 (work in progress),
	February 2019.		October 2020.
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]
	Psenak, P. and S. Previdi, "OSPFv3 Extensions for Segment
	Routing", draft-ietf-ospf-ospfv3-segment-routing-
	extensions-23 (work in progress), January 2019.
	[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-27 (work in progress), December 2018.
	[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,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions		[RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions
	in Support of Generalized Multi-Protocol Label Switching		in Support of Generalized Multi-Protocol Label Switching
	(GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005,		(GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005,
	<https://www.rfc-editor.org/info/rfc4202>.		<https://www.rfc-editor.org/info/rfc4202>.
			[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
			Topology (MT) Routing in Intermediate System to
			Intermediate Systems (IS-ISs)", RFC 5120,
			DOI 10.17487/RFC5120, February 2008,
			<https://www.rfc-editor.org/info/rfc5120>.
			[RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
			DOI 10.17487/RFC5308, October 2008,
			<https://www.rfc-editor.org/info/rfc5308>.
	[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF		[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
	for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,		for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
	<https://www.rfc-editor.org/info/rfc5340>.		<https://www.rfc-editor.org/info/rfc5340>.
	[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>.
	[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and		[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
	skipping to change at page 30, line 5 ¶		skipping to change at page 29, line 36 ¶
	Decraene, B., Litkowski, S., and R. Shakir, "Segment		Decraene, B., Litkowski, S., and R. Shakir, "Segment
	Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,		Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
	July 2018, <https://www.rfc-editor.org/info/rfc8402>.		July 2018, <https://www.rfc-editor.org/info/rfc8402>.
	[RFC8571] Ginsberg, L., Ed., Previdi, S., Wu, Q., Tantsura, J., and		[RFC8571] Ginsberg, L., Ed., Previdi, S., Wu, Q., Tantsura, J., and
	C. Filsfils, "BGP - Link State (BGP-LS) Advertisement of		C. Filsfils, "BGP - Link State (BGP-LS) Advertisement of
	IGP Traffic Engineering Performance Metric Extensions",		IGP Traffic Engineering Performance Metric Extensions",
	RFC 8571, DOI 10.17487/RFC8571, March 2019,		RFC 8571, DOI 10.17487/RFC8571, March 2019,
	<https://www.rfc-editor.org/info/rfc8571>.		<https://www.rfc-editor.org/info/rfc8571>.
			[RFC8665] Psenak, P., Ed., Previdi, S., Ed., Filsfils, C., Gredler,
			H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
			Extensions for Segment Routing", RFC 8665,
			DOI 10.17487/RFC8665, December 2019,
			<https://www.rfc-editor.org/info/rfc8665>.
			[RFC8666] Psenak, P., Ed. and S. Previdi, Ed., "OSPFv3 Extensions
			for Segment Routing", RFC 8666, DOI 10.17487/RFC8666,
			December 2019, <https://www.rfc-editor.org/info/rfc8666>.
			[RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C.,
			Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
			Extensions for Segment Routing", RFC 8667,
			DOI 10.17487/RFC8667, December 2019,
			<https://www.rfc-editor.org/info/rfc8667>.
			[RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri,
			M., and E. Aries, "Advertising Layer 2 Bundle Member Link
			Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668,
			December 2019, <https://www.rfc-editor.org/info/rfc8668>.
	8.2. Informative References		8.2. Informative References
	[I-D.ietf-isis-sr-yang]		[I-D.ietf-isis-sr-yang]
	Litkowski, S., Qu, Y., Sarkar, P., Chen, I., and J.		Litkowski, S., Qu, Y., Sarkar, P., Chen, I., and J.
	Tantsura, "YANG Data Model for IS-IS Segment Routing",		Tantsura, "YANG Data Model for IS-IS Segment Routing",
	draft-ietf-isis-sr-yang-05 (work in progress), March 2019.		draft-ietf-isis-sr-yang-09 (work in progress), January
			2021.
	[I-D.ietf-ospf-sr-yang]		[I-D.ietf-ospf-sr-yang]
	Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem,		Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem,
	"YANG Data Model for OSPF SR (Segment Routing) Protocol",		"YANG Data Model for OSPF SR (Segment Routing) Protocol",
	draft-ietf-ospf-sr-yang-07 (work in progress), March 2019.		draft-ietf-ospf-sr-yang-13 (work in progress), January
			2021.
	[I-D.ietf-spring-segment-routing-ldp-interop]
	Bashandy, A., Filsfils, C., Previdi, S., Decraene, B., and
	S. Litkowski, "Segment Routing interworking with LDP",
	draft-ietf-spring-segment-routing-ldp-interop-15 (work in
	progress), September 2018.
	[I-D.ietf-spring-sr-yang]		[I-D.ietf-spring-sr-yang]
	Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J.		Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J.
	Tantsura, "YANG Data Model for Segment Routing", draft-		Tantsura, "YANG Data Model for Segment Routing", draft-
	ietf-spring-sr-yang-12 (work in progress), February 2019.		ietf-spring-sr-yang-30 (work in progress), January 2021.
	[RFC5706] Harrington, D., "Guidelines for Considering Operations and		[RFC5706] Harrington, D., "Guidelines for Considering Operations and
	Management of New Protocols and Protocol Extensions",		Management of New Protocols and Protocol Extensions",
	RFC 5706, DOI 10.17487/RFC5706, November 2009,		RFC 5706, DOI 10.17487/RFC5706, November 2009,
	<https://www.rfc-editor.org/info/rfc5706>.		<https://www.rfc-editor.org/info/rfc5706>.
			[RFC8661] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
			Decraene, B., and S. Litkowski, "Segment Routing MPLS
			Interworking with LDP", RFC 8661, DOI 10.17487/RFC8661,
			December 2019, <https://www.rfc-editor.org/info/rfc8661>.
	Authors' Addresses		Authors' Addresses
	Stefano Previdi		Stefano Previdi
	Huawei Technologies		Huawei Technologies
	Rome		Rome
	Italy		Italy
	Email: stefano@previdi.net		Email: stefano@previdi.net
	Ketan Talaulikar (editor)		Ketan Talaulikar (editor)
	Cisco Systems, Inc.		Cisco Systems, Inc.
	India		India
	Email: ketant@cisco.com		Email: ketant@cisco.com
	Clarence Filsfils		Clarence Filsfils
	Cisco Systems, Inc.		Cisco Systems, Inc.
	Brussels		Brussels
	Belgium		Belgium
	Email: cfilsfil@cisco.com		Email: cfilsfil@cisco.com
	Hannes Gredler		Hannes Gredler
	RtBrick Inc.		RtBrick Inc.
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