rfc9085.original		rfc9085.txt
	Inter-Domain Routing S. Previdi		Internet Engineering Task Force (IETF) S. Previdi
	Internet-Draft Huawei Technologies		Request for Comments: 9085 Huawei Technologies
	Intended status: Standards Track K. Talaulikar, Ed.		Category: Standards Track K. Talaulikar, Ed.
	Expires: October 17, 2021 C. Filsfils		ISSN: 2070-1721 C. Filsfils
	Cisco Systems, Inc.		Cisco Systems, Inc.
	H. Gredler		H. Gredler
	RtBrick Inc.		RtBrick Inc.
	M. Chen		M. Chen
	Huawei Technologies		Huawei Technologies
	April 15, 2021		August 2021
	BGP Link-State extensions for Segment Routing		Border Gateway Protocol - Link State (BGP-LS) Extensions for Segment
	draft-ietf-idr-bgp-ls-segment-routing-ext-18		Routing
	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 subpaths, called
	"segments". These segments are advertised by routing protocols e.g.		"segments". These segments are advertised by routing protocols,
	by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within		e.g., by the link-state routing protocols (IS-IS, OSPFv2, and OSPFv3)
	IGP topologies.		within IGP topologies.
	This document defines extensions to the BGP Link-state address-family
	in order to carry segment routing information via BGP.
	Requirements Language
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		This document defines extensions to the Border Gateway Protocol -
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		Link State (BGP-LS) address family in order to carry SR information
	"OPTIONAL" in this document are to be interpreted as described in BCP		via BGP.
	14 [RFC2119] [RFC8174] when, and only when, they appear in all
	capitals, as shown here.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This is an Internet Standards Track document.
	provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		This document is a product of the Internet Engineering Task Force
	Task Force (IETF). Note that other groups may also distribute		(IETF). It represents the consensus of the IETF community. It has
	working documents as Internet-Drafts. The list of current Internet-		received public review and has been approved for publication by the
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Internet Engineering Steering Group (IESG). Further information on
			Internet Standards is available in Section 2 of RFC 7841.
	Internet-Drafts are draft documents valid for a maximum of six months		Information about the current status of this document, any errata,
	and may be updated, replaced, or obsoleted by other documents at any		and how to provide feedback on it may be obtained at
	time. It is inappropriate to use Internet-Drafts as reference		https://www.rfc-editor.org/info/rfc9085.
	material or to cite them other than as "work in progress."
	This Internet-Draft will expire on October 17, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2021 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.
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	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
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	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
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction
	2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 5		1.1. Requirements Language
	2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5		2. BGP-LS Extensions for Segment Routing
	2.1.1. SID/Label TLV . . . . . . . . . . . . . . . . . . . . 5		2.1. Node Attribute TLVs
	2.1.2. SR Capabilities TLV . . . . . . . . . . . . . . . . . 6		2.1.1. SID/Label TLV
	2.1.3. SR Algorithm TLV . . . . . . . . . . . . . . . . . . 8		2.1.2. SR Capabilities TLV
	2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8		2.1.3. SR-Algorithm TLV
	2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 10		2.1.4. SR Local Block TLV
	2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 11		2.1.5. SRMS Preference TLV
	2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 11		2.2. Link Attribute TLVs
	2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 12		2.2.1. Adjacency SID TLV
	2.2.3. L2 Bundle Member Attribute TLV . . . . . . . . . . . 14		2.2.2. LAN Adjacency SID TLV
	2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 15		2.2.3. L2 Bundle Member Attributes TLV
	2.3.1. Prefix SID TLV . . . . . . . . . . . . . . . . . . . 16		2.3. Prefix Attribute TLVs
	2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 17		2.3.1. Prefix-SID TLV
	2.3.3. Source Router Identifier TLV . . . . . . . . . . . . 18		2.3.2. Prefix Attribute Flags TLV
	2.3.4. Source OSPF Router-ID TLV . . . . . . . . . . . . . . 19		2.3.3. Source Router Identifier TLV
	2.3.5. Range TLV . . . . . . . . . . . . . . . . . . . . . . 20		2.3.4. Source OSPF Router-ID TLV
	2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 21		2.3.5. Range TLV
	2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 22		2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs
	3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25		2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs
	3.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 25		3. IANA Considerations
	4. Manageability Considerations . . . . . . . . . . . . . . . . 25		3.1. TLV/Sub-TLV Code Points Summary
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 26		4. Manageability Considerations
	6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27		5. Security Considerations
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28		6. References
	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 28		6.1. Normative References
	8.1. Normative References . . . . . . . . . . . . . . . . . . 28		6.2. Informative References
	8.2. Informative References . . . . . . . . . . . . . . . . . 30		Acknowledgements
			Contributors
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30		Authors' Addresses
	1. Introduction		1. Introduction
	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 combining sub-paths called "segments". A segment can		paths by combining subpaths called "segments". A segment can
	represent any instruction: topological or service-based. A segment		represent any instruction: topological or service based. A segment
	can have a local semantic to an SR node or global semantic within a		can have a local semantic to an SR node or global semantic within a
	domain. Within IGP topologies, an SR path is encoded as a sequence		domain. Within IGP topologies, an SR path is encoded as a sequence
	of topological sub-paths, called "IGP segments". These segments are		of topological subpaths, called "IGP segments". These segments are
	advertised by the link-state routing protocols (IS-IS, OSPFv2 and		advertised by the link-state routing protocols (IS-IS, OSPFv2, and
	OSPFv3).		OSPFv3).
	[RFC8402] defines the Link-State IGP segments - Prefix, Node, Anycast		[RFC8402] defines the link-state IGP segments -- prefix, node,
	and Adjacency segments. Prefix segments, by default, represent an		anycast, and adjacency segments. Prefix segments, by default,
	ECMP-aware shortest-path to a prefix, as per the state of the IGP		represent an ECMP-aware shortest-path to a prefix, as per the state
	topology. Adjacency segments represent a hop over a specific		of the IGP topology. Adjacency segments represent a hop over a
	adjacency between two nodes in the IGP. A prefix segment is		specific 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 SR is enabled in an IGP domain, segments are advertised in the
	advertised in the form of Segment Identifiers (SIDs). The IGP link-		form of Segment Identifiers (SIDs). The IGP link-state routing
	state routing protocols have been extended to advertise SIDs and		protocols have been extended to advertise SIDs and other SR-related
	other SR-related information. IGP extensions are described for: IS-		information. IGP extensions are described for: IS-IS [RFC8667],
	IS [RFC8667], OSPFv2 [RFC8665] and OSPFv3 [RFC8666]. Using these		OSPFv2 [RFC8665], and OSPFv3 [RFC8666]. Using these extensions, SR
	extensions, Segment Routing can be enabled within an IGP domain.		can be enabled within an IGP domain.
	Segment Routing (SR) allows advertisement of single or multi-hop		SR allows advertisement of single or multi-hop paths. The flooding
	paths. The flooding scope for the IGP extensions for Segment routing		scope for the IGP extensions for SR is IGP area-wide. Consequently,
	is IGP area-wide. Consequently, the contents of a Link State		the contents of a Link-State Database (LSDB) or a Traffic Engineering
	Database (LSDB) or a Traffic Engineering Database (TED) has the scope		Database (TED) has the scope of an IGP area; therefore, by using the
	of an IGP area and therefore, by using the IGP alone it is not enough		IGP alone, it is not enough to construct segments across multiple IGP
	to construct segments across multiple IGP Area or AS boundaries.		area or Autonomous System (AS) boundaries.
	In order to address the need for applications that require		In order to address the need for applications that require
	topological visibility across IGP areas, or even across Autonomous		topological visibility across IGP areas, or even across ASes, the
	Systems (AS), the BGP-LS address-family/sub-address-family have been		BGP-LS address family / subaddress family have been defined to allow
	defined to allow BGP to carry Link-State information. The BGP		BGP to carry link-state information. The BGP Network Layer
	Network Layer Reachability Information (NLRI) encoding format for		Reachability Information (NLRI) encoding format for BGP-LS and a new
	BGP-LS and a new BGP Path Attribute called the BGP-LS attribute are		BGP Path Attribute called the "BGP-LS Attribute" are defined in
	defined in [RFC7752]. The identifying key of each Link-State object,		[RFC7752]. The identifying key of each link-state object, namely a
	namely a node, link, or prefix, is encoded in the NLRI and the		node, link, or prefix, is encoded in the NLRI, and the properties of
	properties of the object are encoded in the BGP-LS attribute.		the object are encoded in the BGP-LS Attribute.
	+------------+		+------------+
	| Consumer |		| Consumer |
	+------------+		+------------+
	^		^
	|		|
	v		v
	+-------------------+		+-------------------+
	| BGP Speaker | +-----------+		| BGP Speaker | +-----------+
	| (Route-Reflector) | | Consumer |		| (Route Reflector) | | Consumer |
	+-------------------+ +-----------+		+-------------------+ +-----------+
	^ ^ ^ ^		^ ^ ^ ^
	| | | |		| | | |
	+---------------+ | +-------------------+ |		+---------------+ | +-------------------+ |
	| | | |		| | | |
	v v v v		v v v v
	+-----------+ +-----------+ +-----------+		+-----------+ +-----------+ +-----------+
	| BGP | | BGP | | BGP |		| BGP | | BGP | | BGP |
	| Speaker | | Speaker | . . . | Speaker |		| Speaker | | Speaker | . . . | Speaker |
	+-----------+ +-----------+ +-----------+		+-----------+ +-----------+ +-----------+
	^ ^ ^		^ ^ ^
	| | |		| | |
	IGP IGP IGP		IGP IGP IGP
	Figure 1: Link State info collection		Figure 1: Link-State Information Collection
	Figure 1 denotes a typical deployment scenario. In each IGP area,		Figure 1 denotes a typical deployment scenario. In each IGP area,
	one or more nodes are configured with BGP-LS. These BGP speakers		one or more nodes are configured with BGP-LS. These BGP speakers
	form an IBGP mesh by connecting to one or more route-reflectors.		form an Internal BGP (IBGP) mesh by connecting to one or more route
	This way, all BGP speakers (specifically the route-reflectors) obtain		reflectors. This way, all BGP speakers (specifically the route
	Link-State information from all IGP areas (and from other ASes from		reflectors) obtain link-state information from all IGP areas (and
	EBGP peers). An external component connects to the route-reflector		from other ASes from External BGP (EBGP) peers). An external
	to obtain this information (perhaps moderated by a policy regarding		component connects to the route reflector to obtain this information
	what information is or isn't advertised to the external component) as		(perhaps moderated by a policy regarding what information is or isn't
	described in [RFC7752].		advertised to the external component) as described in [RFC7752].
	This document describes extensions to BGP-LS to advertise the SR		This document describes extensions to BGP-LS to advertise the SR
	information. An external component (e.g., a controller) can collect		information. An external component (e.g., a controller) can collect
	SR information from across an SR domain (as described in [RFC8402])		SR information from across an SR domain (as described in [RFC8402])
	and construct the end-to-end path (with its associated SIDs) that		and construct the end-to-end path (with its associated SIDs) that
	need to be applied to an incoming packet to achieve the desired end-		needs to be applied to an incoming packet to achieve the desired end-
	to-end forwarding. SR operates within a trusted domain consisting of		to-end forwarding. SR operates within a trusted domain consisting of
	a single or multiple ASes managed by the same administrative entity		a single AS or multiple ASes managed by the same administrative
	e.g. within a single provider network.		entity, e.g., within a single provider network.
			1.1. Requirements Language
			The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
			"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
			"OPTIONAL" in this document are to be interpreted as described in BCP
			14 [RFC2119] [RFC8174] when, and only when, they appear in all
			capitals, as shown here.
	2. BGP-LS Extensions for Segment Routing		2. BGP-LS Extensions for Segment Routing
	This document defines SR extensions to BGP-LS and specifies the TLVs		This document defines SR extensions to BGP-LS and specifies the TLVs
	and sub-TLVs for advertising SR information within the BGP-LS		and sub-TLVs for advertising SR information within the BGP-LS
	Attribute. Section 2.4 and Section 2.5 lists the equivalent TLVs and		Attribute. Sections 2.4 and 2.5 list the equivalent TLVs and sub-
	sub-TLVs in IS-IS, OSPFv2 and OSPFv3 protocols.		TLVs in the IS-IS, OSPFv2, and OSPFv3 protocols.
	BGP-LS [RFC7752] defines the BGP-LS NLRI that can be a Node NLRI, a		BGP-LS [RFC7752] defines the BGP-LS NLRI that can be a Node NLRI, a
	Link NLRI or a Prefix NLRI. BGP-LS [RFC7752] defines the TLVs that		Link NLRI, or a Prefix NLRI, and it defines the TLVs that map link-
	map link-state information to BGP-LS NLRI within the BGP-LS		state information to BGP-LS NLRI within the BGP-LS Attribute. This
	Attribute. This document adds additional BGP-LS Attribute TLVs in		document adds additional BGP-LS Attribute TLVs in order to encode SR
	order to encode SR information. It does not introduce any changes to		information. It does not introduce any changes to the encoding of
	the encoding of the BGP-LS NLRIs.		the BGP-LS NLRIs.
	2.1. Node Attributes TLVs		2.1. Node Attribute TLVs
	The following Node Attribute TLVs are defined:		The following Node Attribute TLVs are defined:
	+------+-----------------+---------------+		+======+=================+===============+
	| Type | Description | Section |		| Type | Description | Section |
	+------+-----------------+---------------+		+======+=================+===============+
	| 1161 | SID/Label | Section 2.1.1 |		| 1161 | SID/Label | Section 2.1.1 |
			+------+-----------------+---------------+
	| 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 |
	+------+-----------------+---------------+		+------+-----------------+---------------+
	Table 1: Node Attribute TLVs		Table 1: Node 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 Node NLRI describing the IGP node that is originating the		with the Node NLRI that describes the IGP node that is originating
	corresponding IGP TLV/sub-TLV described below.		the 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		* IS-IS, as defined by the SID/Label Sub-TLV in Section 2.3 of
	[RFC8667].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SID/Label sub-TLV in section 2.1		* OSPFv2/OSPFv3, as defined by the SID/Label Sub-TLV in Section 2.1
	of [RFC8665] and section 3.1 of [RFC8666].		of [RFC8665] and Section 3.1 of [RFC8666].
	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) //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 2: SID/Label TLV Format		Figure 2: SID/Label TLV Format
	Where:		Where:
	Type: 1161		Type: 1161
	Length: Variable. Either 3 or 4 depending whether the value is		Length: Variable. Either 3 or 4 octets depending on whether the
	encoded as a label or as an index/SID.		value is encoded as a label or as an index/SID.
	SID/Label: If length is set to 3, then the 20 rightmost bits		SID/Label: If the length is set to 3, then the 20 rightmost bits
	represent a label (the total TLV size is 7) and the 4 leftmost		represent a label (the total TLV size is 7), and the 4 leftmost
	bits are set to 0. If length is set to 4, then the value		bits are set to 0. If the length is set to 4, then the value
	represents a 32 bit SID (the total TLV size is 8).		represents a 32-bit SID (the total TLV size is 8).
	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		* IS-IS, as defined by the SR-Capabilities Sub-TLV in Section 3.1 of
	[RFC8667].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in section		* OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in
	3.2 of [RFC8665]. OSPFv3 leverages the same TLV as defined for		Section 3.2 of [RFC8665]. OSPFv3 leverages the same TLV as
	OSPFv2.		defined for 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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Range Size 1 |		| Range Size 1 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label sub-TLV 1 //		| SID/Label Sub-TLV 1 //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	...		...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Range Size N |		| Range Size N |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label sub-TLV N //		| SID/Label Sub-TLV N //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	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. The minimum length is 12 octets.
	Flags: 1 octet of flags as defined in section 3.1 of [RFC8667] for		Flags: 1 octet of flags as defined in Section 3.1 of [RFC8667] for
	IS-IS. The flags are not currently defined for OSPFv2 and OSPFv3		IS-IS. The flags are not currently defined for OSPFv2 and OSPFv3
	and MUST be set to 0 and ignored on receipt.		and MUST be 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, 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 octets 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 a sub-TLV,
	which encodes the first label in the range. Since the SID/		which encodes the first label in the range. Since the SID/
	Label TLV is used to indicate the first label of the SRGB		Label TLV is used to indicate the first label of the SRGB
	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
	specific advertisements.		protocol-specific advertisements.
	o IS-IS, as defined by the SR-Algorithm sub-TLV in section 3.2 of		* IS-IS, as defined by the SR-Algorithm Sub-TLV in Section 3.2 of
	[RFC8667].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SR-Algorithm TLV in section 3.1		* OSPFv2/OSPFv3, as defined by the SR-Algorithm TLV in Section 3.1
	of [RFC8665]. OSPFv3 leverages the same TLV as defined for		of [RFC8665]. OSPFv3 leverages 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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 4: SR Algorithm TLV Format		Figure 4: SR-Algorithm TLV Format
	Where:		Where:
	Type: 1035		Type: 1035
	Length: Variable. Minimum length is 1 and maximum can be 256.		Length: Variable. The minimum length is 1 octet and the maximum can
			be 256.
	Algorithm: One or more fields of 1 octet each identifying the		Algorithm: One or more fields of 1 octet each that identifies the
	algorithm.		algorithm.
	2.1.4. SR Local Block TLV		2.1.4. SR Local Block TLV
	The SR Local Block (SRLB) TLV contains the range(s) of labels the		The SRLB TLV contains the range(s) of labels the node has reserved
	node has reserved for local SIDs. Local SIDs are used, e.g., in IGP		for local SIDs. Local SIDs are used, e.g., in IGP (IS-IS, OSPF) for
	(IS-IS, OSPF) for Adjacency-SIDs, and may also be allocated by		Adjacency SIDs and may also be allocated by components other than IGP
	components other than IGP protocols. As an example, an application		protocols. As an example, an application or a controller may
	or a controller may instruct a node to allocate a specific local SID.		instruct a node to allocate a specific local SID. Therefore, in
	Therefore, in order for such applications or controllers to know the		order for such applications or controllers to know the range of local
	range of local SIDs available, it is required that the node		SIDs available, the node is required to advertise 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		* IS-IS, as defined by the SRLB Sub-TLV in Section 3.3 of [RFC8667].
	[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SR Local Block TLV in section		* OSPFv2/OSPFv3, as defined by the SR Local Block TLV in Section 3.3
	3.3. of [RFC8665]. OSPFv3 leverages the same TLV as defined for		of [RFC8665]. OSPFv3 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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Sub-Range Size 1 |		| Sub-Range Size 1 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label sub-TLV 1 //		| SID/Label Sub-TLV 1 //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	...		...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Sub-Range Size N |		| Sub-Range Size N |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label sub-TLV N //		| SID/Label Sub-TLV N //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 5: SRLB TLV Format		Figure 5: SRLB TLV Format
	Where:		Where:
	Type: 1036		Type: 1036
	Length: Variable. Minimum length is 12.		Length: Variable. The minimum length is 12 octets.
	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
	of [RFC8667] for IS-IS. The flags are not currently defined for		[RFC8667] for IS-IS. The flags are not currently defined for
	OSPFv2 and OSPFv3 and MUST be set to 0 and ignored on receipt.		OSPFv2 and OSPFv3 and MUST be 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 a 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
	the range.		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 a 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. [RFC8661] specifies the SRMS functionality along		particular source. [RFC8661] specifies the SRMS functionality along
	with SRMS preference of the node advertising the SRMS Prefix-to-SID		with the SRMS preference of the node advertising the SRMS Prefix-to-
	Mapping ranges.		SID 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		* IS-IS, as defined by the SRMS Preference Sub-TLV in Section 3.4 of
	[RFC8667].		[RFC8667].
	o OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in section		* OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in
	3.4 of [RFC8665]. OSPFv3 leverages the same TLV as defined for		Section 3.4 of [RFC8665]. OSPFv3 leverages the same TLV as
	OSPFv2.		defined for 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 |
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	Figure 6: SRMS Preference TLV Format		Figure 6: SRMS Preference TLV Format
	Where:		Where:
	Type: 1037		Type: 1037
	Length: 1.		Length: 1 octet
	Preference: 1 octet carrying an unsigned 8 bit SRMS preference.		Preference: 1 octet carrying an unsigned 8-bit SRMS preference.
	2.2. Link Attribute TLVs		2.2. Link Attribute TLVs
	The following Link Attribute TLVs are are defined:		The following Link Attribute TLVs are defined:
	+------+-----------------------+---------------+		+======+=================================+===============+
	| Type | Description | Section |		| Type | Description | Section |
	+------+-----------------------+---------------+		+======+=================================+===============+
	| 1099 | Adjacency SID TLV | Section 2.2.1 |		| 1099 | Adjacency SID TLV | Section 2.2.1 |
	| 1100 | LAN Adjacency SID TLV | Section 2.2.2 |		+------+---------------------------------+---------------+
	| 1172 | L2 Bundle Member TLV | Section 2.2.3 |		| 1100 | LAN Adjacency SID TLV | Section 2.2.2 |
	+------+-----------------------+---------------+		+------+---------------------------------+---------------+
			| 1172 | L2 Bundle Member Attributes TLV | Section 2.2.3 |
			+------+---------------------------------+---------------+
	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 that describes 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 the
	SID sub-TLV of IS-IS (section 2.2.1 of [RFC8667]), OSPFv2 (section		Adj-SID Sub-TLV of IS-IS (Section 2.2.1 of [RFC8667]), OSPFv2
	6.1 of [RFC8665]) and OSPFv3 (section 7.1 of [RFC8666]).		(Section 6.1 of [RFC8665]), and OSPFv3 (Section 7.1 of [RFC8666]).
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| 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 octets depending on the label or
	encoding of the SID		index encoding of the SID.
	Flags. 1 octet value which should be set as:		Flags: 1-octet value that should be set as:
	* IS-IS Adj-SID flags are defined in section 2.2.1 of [RFC8667].		* IS-IS Adj-SID flags as defined in Section 2.2.1 of [RFC8667].
	* OSPFv2 Adj-SID flags are defined in section 6.1 of [RFC8665].		* OSPFv2 Adj-SID flags as defined in Section 6.1 of [RFC8665].
	* OSPFv3 Adj-SID flags are defined in section 7.1 of [RFC8666].		* OSPFv3 Adj-SID flags as defined in Section 7.1 of [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.
	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
	[RFC8667].		[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
	[RFC8665].		[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
	[RFC8666].		[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		pseudonode (or the equivalent OSPF Designated and Backup Designated
	Routers). The LAN Adjacency Segment TLV allows a node to announce		Routers). The LAN Adjacency SID 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 the LAN-Adj-SID Sub-TLV of IS-IS
	(section 2.2.2 of [RFC8667]) and LAN Adj-SID sub-TLV of OSPFv2		(Section 2.2.2 of [RFC8667]), the LAN Adj-SID Sub-TLV of OSPFv2
	(section 6.2 of [RFC8665]) and OSPFv3 (section 7.2 of [RFC8666]).		(Section 6.2 of [RFC8665]), and the LAN Adj-SID Sub-TLV of OSPFv3
			(Section 7.2 of [RFC8666]).
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| OSPF Neighbor ID / IS-IS System-ID |		| OSPF Neighbor ID / IS-IS System ID |
	+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |		| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Label/Index (variable) //		| SID/Label/Index (variable) //
	+---------------------------------------------------------------+		+---------------------------------------------------------------+
	Figure 8: LAN Adjacency SID TLV Format		Figure 8: LAN Adjacency SID TLV Format
	Where:		Where:
	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 octets depending
	Label or Index encoding of the SID. For OSPF it would be 11 or 12		on the label or index encoding of the SID. For OSPF, it would be
	depending on Label or Index encoding of the SID.		11 or 12 octets depending on the label or index encoding of the
			SID.
	Flags. 1 octet value which should be set as:		Flags: 1-octet value that should be set as:
	* IS-IS LAN Adj-SID flags are defined in section 2.2.2 of		* IS-IS LAN Adj-SID flags as defined in Section 2.2.2 of
	[RFC8667].		[RFC8667].
	* OSPFv2 LAN Adj-SID flags are defined in section 6.2 of		* OSPFv2 LAN Adj-SID flags as defined in Section 6.2 of
	[RFC8665].		[RFC8665].
	* OSPFv3 LAN Adj-SID flags are defined in section 7.2 of		* OSPFv3 LAN Adj-SID flags as defined in Section 7.2 of
	[RFC8666].		[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
	[RFC8667].		[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
	[RFC8665].		[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
	[RFC8666].		[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 Attributes TLV
	The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member		The L2 Bundle Member Attributes 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 Attributes TLV is associated with the Link NLRI. The TLV MAY
	include sub-TLVs which describe attributes associated with the bundle		include sub-TLVs that 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 Attributes 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 [RFC8668]). The equivalent functionality has not		IS-IS (Section 2 of [RFC8668]). The equivalent 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 Attributes 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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Link attribute sub-TLVs(variable) //		| Link Attribute Sub-TLVs(variable) //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 9: L2 Bundle Member Attributes TLV Format		Figure 9: L2 Bundle Member Attributes TLV Format
	Where:		Where:
	Type: 1172		Type: 1172
	Length: Variable.		Length: Variable.
	L2 Bundle Member Descriptor: 4 octets field that carries a Link		L2 Bundle Member Descriptor: 4-octet field that carries a link-local
	Local Identifier as defined in [RFC4202].		identifier as defined in [RFC4202].
	Link attributes for L2 Bundle Member Links are advertised as sub-TLVs		Link attributes for L2 Bundle Member links are advertised as sub-TLVs
	of the L2 Bundle Member Attribute TLV. The sub-TLVs are identical to		of the L2 Bundle Member Attributes TLV. The sub-TLVs are identical
	existing BGP-LS TLVs as identified in the table below.		to existing BGP-LS TLVs as identified in the table below.
	+-------------+------------------------------------+----------------+		+================+==========================+====================+
	| TLV Code | Description | Reference |		| TLV Code Point | Description | Reference Document |
	| Point | | Document |		+================+==========================+====================+
	+-------------+------------------------------------+----------------+		| 1088 | Administrative group | [RFC7752] |
	| 1088 | Administrative group (color) | [RFC7752] |		| | (color) | |
	| 1089 | Maximum link bandwidth | [RFC7752] |		+----------------+--------------------------+--------------------+
	| 1090 | Max. reservable link bandwidth | [RFC7752] |		| 1089 | Maximum link bandwidth | [RFC7752] |
	| 1091 | Unreserved bandwidth | [RFC7752] |		+----------------+--------------------------+--------------------+
	| 1092 | TE default metric | [RFC7752] |		| 1090 | Max. reservable link | [RFC7752] |
	| 1093 | Link protection type | [RFC7752] |		| | bandwidth | |
	| 1099 | Adjacency Segment Identifier (Adj- | Section 2.2.1 |		+----------------+--------------------------+--------------------+
	| | SID) TLV | |		| 1091 | Unreserved bandwidth | [RFC7752] |
	| 1100 | LAN Adjacency Segment Identifier | Section 2.2.2 |		+----------------+--------------------------+--------------------+
	| | (Adj-SID) TLV | |		| 1092 | TE default metric | [RFC7752] |
	| 1114 | Unidirectional link delay | [RFC8571] |		+----------------+--------------------------+--------------------+
	| 1115 | Min/Max Unidirectional link delay | [RFC8571] |		| 1093 | Link protection type | [RFC7752] |
	| 1116 | Unidirectional Delay Variation | [RFC8571] |		+----------------+--------------------------+--------------------+
	| 1117 | Unidirectional packet loss | [RFC8571] |		| 1099 | Adjacency Segment | Section 2.2.1 |
	| 1118 | Unidirectional residual bandwidth | [RFC8571] |		| | Identifier (Adj-SID) TLV | |
	| 1119 | Unidirectional available bandwidth | [RFC8571] |		+----------------+--------------------------+--------------------+
	| 1120 | Unidirectional bandwidth | [RFC8571] |		| 1100 | LAN Adjacency Segment | Section 2.2.2 |
	| | utilization | |		| | Identifier (Adj-SID) TLV | |
	+-------------+------------------------------------+----------------+		+----------------+--------------------------+--------------------+
			| 1114 | Unidirectional link | [RFC8571] |
			| | delay | |
			+----------------+--------------------------+--------------------+
			| 1115 | Min/Max Unidirectional | [RFC8571] |
			| | link delay | |
			+----------------+--------------------------+--------------------+
			| 1116 | Unidirectional Delay | [RFC8571] |
			| | Variation | |
			+----------------+--------------------------+--------------------+
			| 1117 | Unidirectional Link Loss | [RFC8571] |
			+----------------+--------------------------+--------------------+
			| 1118 | Unidirectional residual | [RFC8571] |
			| | bandwidth | |
			+----------------+--------------------------+--------------------+
			| 1119 | Unidirectional available | [RFC8571] |
			| | bandwidth | |
			+----------------+--------------------------+--------------------+
			| 1120 | Unidirectional Utilized | [RFC8571] |
			| | Bandwidth | |
			+----------------+--------------------------+--------------------+
	Table 3: BGP-LS Attribute TLVs also used as sub-TLVs of L2 Bundle		Table 3: BGP-LS Attribute TLVs are also used as sub-TLVs of
	Member Attribute TLV		the L2 Bundle Member Attributes 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 2.3.5 |		+------+--------------------------+---------------+
	| 1170 | Prefix Attribute Flags | Section 2.3.2 |		| 1159 | Range | Section 2.3.5 |
	| 1171 | Source Router Identifier | Section 2.3.3 |		+------+--------------------------+---------------+
	| 1174 (suggested) | Source OSPF Router-ID | Section 2.3.4 |		| 1170 | Prefix Attribute Flags | Section 2.3.2 |
	+------------------+--------------------------+---------------+		+------+--------------------------+---------------+
			| 1171 | Source Router Identifier | Section 2.3.3 |
			+------+--------------------------+---------------+
			| 1174 | 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 that describes the prefix of the IGP node that
	originating the corresponding IGP TLV/sub-TLV described below.		is 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 the Prefix-SID
	of IS-IS (section 2.1 of [RFC8667]) and the Prefix SID sub-TLV of		Sub-TLV of IS-IS (Section 2.1 of [RFC8667]), the Prefix-SID Sub-TLV
	OSPFv2 (section 5 of [RFC8665]) and OSPFv3 (section 6 of [RFC8666]).		of OSPFv2 (Section 5 of [RFC8665]), and the Prefix-SID Sub-TLV of
			OSPFv3 (Section 6 of [RFC8666]).
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SID/Index/Label (variable) //		| SID/Index/Label (variable) //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 10: Prefix SID TLV Format		Figure 10: Prefix-SID TLV Format
	Where:		Where:
	Type: 1158		Type: 1158
	Length: Variable. 7 or 8 depending on Label or Index encoding of		Length: Variable. 7 or 8 octets depending on the label or index
	the SID		encoding of the SID.
	Flags: 1 octet value which should be set as:		Flags: 1-octet value that should be set as:
	* IS-IS Prefix SID flags are defined in section 2.1.1 of		* IS-IS Prefix-SID flags as defined in Section 2.1.1 of
	[RFC8667].		[RFC8667].
	* OSPFv2 Prefix SID flags are defined in section 5 of [RFC8665].		* OSPFv2 Prefix-SID flags as defined in Section 5 of [RFC8665].
	* OSPFv3 Prefix SID flags are defined in section 6 of [RFC8666].		* OSPFv3 Prefix-SID flags as defined in Section 6 of [RFC8665].
	Algorithm: 1 octet value identify the algorithm. The semantics of		Algorithm: 1-octet value identifies the algorithm. The semantics of
	algorithm are described in section 3.1.1 of [RFC8402].		the 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
	[RFC8667].		[RFC8667].
	* OSPFv2: Label or index value as defined in section 5 of		OSPFv2: Label or index value as defined in Section 5 of
	[RFC8665].		[RFC8665].
	* OSPFv3: Label or index value as defined in section 6 of		OSPFv3: Label or index value as defined in Section 6 of
	[RFC8666].		[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
	is used to determine the underlying protocol specification for		NLRI 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
	flags information. These flags are defined for OSPFv2 in section 2.1		flags information. These flags are defined for OSPFv2 in Section 2.1
	of [RFC7684], for OSPFv3 in section A.4.1.1 of [RFC5340] and for IS-		of [RFC7684], OSPFv3 in Appendix A.4.1.1 of [RFC5340], and IS-IS in
	IS in section 2.1 of [RFC7794].		Section 2.1 of [RFC7794].
	The Prefix Attribute Flags TLV has the following format:		The Prefix Attribute Flags 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 (variable) //		| Flags (variable) //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 11: Prefix Attribute Flags TLV Format		Figure 11: Prefix Attribute Flags TLV Format
	Where:		Where:
	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).
	field). Flags are routing protocol specific and are to be set as		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]. In the		Attribute Flags defined in Section 2.1 of [RFC7794]. In the
	case of the X-flag when associated with IPv6 prefix		case of the X-flag when associated with IPv6 prefix
	reachability, the setting corresponds to the setting of the		reachability, the setting corresponds to the setting of the
	X-flag in the fixed format of IS-IS TLVs 236 [RFC5308] and 237		X-flag in the fixed format of IS-IS TLVs 236 [RFC5308] and 237
	[RFC5120].		[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
	A.4.1.1 of [RFC5340] and extended in section 3.1 of [RFC8362]		Appendix 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 TLV		2.3.3. Source Router Identifier TLV
	The Source Router Identifier TLV contains the IPv4 or IPv6 Router		The Source Router Identifier TLV contains the IPv4 or IPv6 Router
	Identifier of the originator of the Prefix. For the IS-IS protocol		Identifier of the originator of the prefix. For the IS-IS protocol,
	this is derived from the IPv4/IPv6 Source Router ID sub-TLV as		this is derived from the IPv4/IPv6 Source Router ID Sub-TLV as
	defined in section 2.2 of [RFC7794]. For the OSPF protocol, this is		defined in Section 2.2 of [RFC7794]. For the OSPF protocol, this is
	derived from the Prefix Source Router Address sub-TLV as defined in		derived from the Prefix Source Router Address Sub-TLV as defined in
	section 2.2 of [I-D.ietf-lsr-ospf-prefix-originator].		Section 2.2 of [RFC9084].
	The Source Router Identifier 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 Identifier //		| 4- or 16-octet Router Identifier //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 12: Source Router Identifier TLV Format		Figure 12: Source Router Identifier TLV Format
	Where:		Where:
	Type: 1171		Type: 1171
	Length: Variable. 4 or 16 for IPv4 and IPv6 prefix respectively.		Length: Variable. 4 or 16 octets for the IPv4 or 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 the case of IS-IS, and the
	IPv4 or IPv6 Router Address in the case of OSPF.		IPv4 or IPv6 Router Address in the case of OSPF.
	2.3.4. Source OSPF Router-ID TLV		2.3.4. Source OSPF Router-ID TLV
	The Source OSPF Router-ID TLV is applicable only for the OSPF		The Source OSPF Router-ID TLV is applicable only for the OSPF
	protocol and contains OSPF Router-ID of the originator of the Prefix.		protocol and contains the OSPF Router-ID of the originator of the
	It is derived from the Prefix Source OSPF Router-ID sub-TLV as		prefix. It is derived from the Prefix Source OSPF Router-ID Sub-TLV
	defined in section 2.1 of [I-D.ietf-lsr-ospf-prefix-originator].		as defined in Section 2.1 of [RFC9084].
	The Source OSPF Router-ID TLV has the following format:		The Source OSPF Router-ID 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 octet OSPF Router-ID //		| 4-octet OSPF Router-ID //
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 13: Source OSPF Router-ID TLV Format		Figure 13: Source OSPF Router-ID TLV Format
	Where:		Where:
	Type: 1174 (suggested)		Type: 1174
	Length: 4		Length: 4 octets
	OSPF Router-ID: the OSPF Router-ID of the node originating the		OSPF Router-ID: the OSPF Router-ID of the node originating the
	prefix.		prefix.
	2.3.5. Range TLV		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 SRMS functionality [RFC8661], as defined in
	functionality [RFC8661], as defined in the respective underlying IGP		the respective underlying IGP SR extensions: Section 4 of [RFC8665],
	SR extensions [RFC8665] (section 4), [RFC8666] (section 5) and		Section 5 of [RFC8666], and Section 2.4 of [RFC8667]. The
	[RFC8667] (section 2.4). The information advertised in the Range TLV		information advertised in the Range TLV is derived from the SID/Label
	is derived from the SID/Label Binding TLV in the case of IS-IS and		Binding TLV in the case of IS-IS and the OSPFv2/OSPFv3 Extended
	the OSPFv2/OSPFv3 Extended Prefix Range TLV in the case of OSPFv2/		Prefix Range TLV in the case of OSPFv2/OSPFv3.
	OSPFv3.
	A Prefix NLRI, that been advertised with a Range TLV, is considered a		A Prefix NLRI, that has been advertised with a Range TLV, is
	normal routing prefix (i.e. prefix reachability) only when there is		considered a normal routing prefix (i.e., prefix reachability) only
	also an IGP metric TLV (TLV 1095) associated it. Otherwise, it is		when there is also an IGP metric TLV (TLV 1095) associated it.
	considered only as the first prefix in the range for prefix-to-SID		Otherwise, it is considered only as the first prefix in the range for
	mapping advertisement.		prefix-to-SID 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 14: 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 octets depending on the label or index
	the SID		encoding of the SID.
	Flags: 1 octet value which should be set as:		Flags: 1-octet value that 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 as defined in Section 2.4.1
	of [RFC8667].		of [RFC8667].
	* OSPFv2 OSPF Extended Prefix Range TLV flags are defined in		* OSPFv2 OSPF Extended Prefix Range TLV flags as defined in
	section 4 of [RFC8665].		Section 4 of [RFC8665].
	* OSPFv3 Extended Prefix Range TLV flags are defined in section 5		* OSPFv3 Extended Prefix Range TLV flags as defined in Section 5
	of [RFC8666].		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.
	The prefix-to-SID mappings are advertised using sub-TLVs as below:		The prefix-to-SID mappings are advertised using sub-TLVs as below:
	IS-IS:		IS-IS:
	SID/Label Range TLV		SID/Label Range TLV
	Prefix-SID sub-TLV		Prefix-SID Sub-TLV
	OSPFv2/OSPFv3:		OSPFv2/OSPFv3:
	OSPFv2/OSPFv3 Extended Prefix Range TLV		OSPFv2/OSPFv3 Extended Prefix Range TLV
	Prefix SID sub-TLV		Prefix-SID Sub-TLV
	BGP-LS:		BGP-LS:
	Range TLV		Range TLV
	Prefix-SID TLV (used as a sub-TLV in this context)		Prefix-SID TLV (used as a sub-TLV in this context)
	The prefix-to-SID mapping information for the BGP-LS Prefix-SID TLV		The prefix-to-SID mapping information for the BGP-LS Prefix-SID TLV
	(used as sub-TLV in this context) is encoded as described in		(used as a sub-TLV in this context) is encoded as described in
	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 illustrates the IS-IS Segment Routing Extensions TLVs
	sub-TLVs mapped to the ones defined in this document.		and sub-TLVs mapped to the ones defined in this document.
	The following table, illustrates for each BGP-LS TLV, its equivalence		For each BGP-LS TLV, the following table illustrates its equivalence
	in IS-IS.		in IS-IS.
	+----------------------+--------------------------------+-----------+		+========================+==============================+===========+
	| Description | IS-IS TLV/sub-TLV | Reference |		| Description | IS-IS TLV/sub-TLV | Reference |
	+----------------------+--------------------------------+-----------+		+========================+==============================+===========+
	| SR Capabilities | SR-Capabilities sub-TLV (2) | [RFC8667] |		| SR Capabilities | SR-Capabilities Sub-TLV (2) | [RFC8667] |
	| SR Algorithm | SR-Algorithm sub-TLV (19) | [RFC8667] |		+------------------------+------------------------------+-----------+
	| SR Local Block | SR Local Block sub-TLV (22) | [RFC8667] |		| SR Algorithm | SR-Algorithm Sub-TLV (19) | [RFC8667] |
	| SRMS Preference | SRMS Preference sub-TLV (19) | [RFC8667] |		+------------------------+------------------------------+-----------+
	| Adjacency SID | Adj-SID sub-TLV (31) | [RFC8667] |		| SR Local Block | SR Local Block Sub-TLV (22) | [RFC8667] |
	| LAN Adjacency SID | LAN-Adj-SID sub-TLV (32) | [RFC8667] |		+------------------------+------------------------------+-----------+
	| Prefix SID | Prefix-SID sub-TLV (3) | [RFC8667] |		| SRMS Preference | SRMS Preference Sub-TLV (19) | [RFC8667] |
	| Range | SID/Label Binding TLV (149) | [RFC8667] |		+------------------------+------------------------------+-----------+
	| SID/Label | SID/Label sub-TLV (1) | [RFC8667] |		| Adjacency SID | Adj-SID Sub-TLV (31) | [RFC8667] |
	| Prefix Attribute | Prefix Attributes Flags sub- | [RFC7794] |		+------------------------+------------------------------+-----------+
	| Flags | TLV (4) | |		| LAN Adjacency SID | LAN-Adj-SID Sub-TLV (32) | [RFC8667] |
	| Source Router | IPv4/IPv6 Source Router ID | [RFC7794] |		+------------------------+------------------------------+-----------+
	| Identifier | sub-TLV (11/12) | |		| Prefix-SID | Prefix-SID Sub-TLV (3) | [RFC8667] |
	| L2 Bundle Member | L2 Bundle Member Attributes | [RFC8668] |		+------------------------+------------------------------+-----------+
	| Attributes | TLV (25) | |		| Range | SID/Label Binding TLV (149) | [RFC8667] |
	+----------------------+--------------------------------+-----------+		+------------------------+------------------------------+-----------+
			| SID/Label | SID/Label Sub-TLV (1) | [RFC8667] |
			+------------------------+------------------------------+-----------+
			| Prefix Attribute | Prefix Attribute Flags Sub- | [RFC7794] |
			| Flags | TLV (4) | |
			+------------------------+------------------------------+-----------+
			| Source Router | IPv4/IPv6 Source Router ID | [RFC7794] |
			| Identifier | Sub-TLV (11/12) | |
			+------------------------+------------------------------+-----------+
			| L2 Bundle Member | L2 Bundle Member Attributes | [RFC8668] |
			| 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 illustrates 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		For each BGP-LS TLV, the following tables illustrate its equivalence
	in OSPFv2 and OSPFv3.		in OSPFv2 and OSPFv3.
	+-------------+--------------+--------------------------------------+		+===================+==========================+===========+
	| Description | OSPFv2 | Reference |		| Description | OSPFv2 TLV/sub-TLV | Reference |
	| | TLV/sub-TLV | |		+===================+==========================+===========+
	+-------------+--------------+--------------------------------------+		| SR Capabilities | SID/Label Range TLV (9) | [RFC8665] |
	| SR Capabili | SID/Label | [RFC8665] |		+-------------------+--------------------------+-----------+
	| ties | Range TLV | |		| SR Algorithm | SR-Algorithm TLV (8) | [RFC8665] |
	| | (9) | |		+-------------------+--------------------------+-----------+
	| SR | SR-Algorithm | [RFC8665] |		| SR Local Block | SR Local Block TLV (14) | [RFC8665] |
	| Algorithm | TLV (8) | |		+-------------------+--------------------------+-----------+
	| SR Local | SR Local | [RFC8665] |		| SRMS Preference | SRMS Preference TLV (15) | [RFC8665] |
	| Block | Block TLV | |		+-------------------+--------------------------+-----------+
	| | (14) | |		| Adjacency SID | Adj-SID Sub-TLV (2) | [RFC8665] |
	| SRMS | SRMS | [RFC8665] |		+-------------------+--------------------------+-----------+
	| Preference | Preference | |		| LAN Adjacency SID | LAN Adj-SID Sub-TLV (3) | [RFC8665] |
	| | TLV (15) | |		+-------------------+--------------------------+-----------+
	| Adjacency | Adj-SID sub- | [RFC8665] |		| Prefix-SID | Prefix-SID Sub-TLV (2) | [RFC8665] |
	| SID | TLV (2) | |		+-------------------+--------------------------+-----------+
	| LAN | LAN Adj-SID | [RFC8665] |		| Range | OSPF Extended Prefix | [RFC8665] |
	| Adjacency | sub-TLV (3) | |		| | Range TLV (2) | |
	| SID | | |		+-------------------+--------------------------+-----------+
	| Prefix SID | Prefix SID | [RFC8665] |		| SID/Label | SID/Label Sub-TLV (1) | [RFC8665] |
	| | sub-TLV (2) | |		+-------------------+--------------------------+-----------+
	| Range | OSPF | [RFC8665] |		| Prefix Attribute | Flags of OSPFv2 Extended | [RFC7684] |
	| | Extended | |		| Flags | Prefix TLV (1) | |
	| | Prefix Range | |		+-------------------+--------------------------+-----------+
	| | TLV (2) | |		| Source Router | Prefix Source Router | [RFC9084] |
	| SID/Label | SID/Label | [RFC8665] |		| Identifier | Address Sub-TLV (5) | |
	| | sub-TLV (1) | |		+-------------------+--------------------------+-----------+
	| Prefix | Flags of | [RFC7684] |		| Source OSPF | Prefix Source OSPF | [RFC9084] |
	| Attribute | OSPFv2 | |		| Router-ID | Router-ID Sub-TLV (4) | |
	| Flags | Extended | |		+-------------------+--------------------------+-----------+
	| | Prefix TLV | |
	| | (1) | |
	| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| Router | Source | ] |
	| Identifier | Router-ID | |
	| | sub-TLV (4) | |
	| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| Router-ID | Source OSPF | ] |
	| | Router-ID | |
	| | sub-TLV (5) | |
	+-------------+--------------+--------------------------------------+
	Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs		Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs
	+-------------+--------------+--------------------------------------+		+===================+==========================+===========+
	| Description | OSPFv3 | Reference |		| Description | OSPFv3 TLV/sub-TLV | Reference |
	| | TLV/sub-TLV | |		+===================+==========================+===========+
	+-------------+--------------+--------------------------------------+		| SR Capabilities | SID/Label Range TLV (9) | [RFC8665] |
	| SR Capabili | SID/Label | [RFC8665] |		+-------------------+--------------------------+-----------+
	| ties | Range TLV | |		| SR Algorithm | SR-Algorithm TLV (8) | [RFC8665] |
	| | (9) | |		+-------------------+--------------------------+-----------+
	| SR | SR-Algorithm | [RFC8665] |		| SR Local Block | SR Local Block TLV (14) | [RFC8665] |
	| Algorithm | TLV (8) | |		+-------------------+--------------------------+-----------+
	| SR Local | SR Local | [RFC8665] |		| SRMS Preference | SRMS Preference TLV (15) | [RFC8665] |
	| Block | Block TLV | |		+-------------------+--------------------------+-----------+
	| | (14) | |		| Adjacency SID | Adj-SID Sub-TLV (5) | [RFC8666] |
	| SRMS | SRMS | [RFC8665] |		+-------------------+--------------------------+-----------+
	| Preference | Preference | |		| LAN Adjacency SID | LAN Adj-SID Sub-TLV (6) | [RFC8666] |
	| | TLV (15) | |		+-------------------+--------------------------+-----------+
	| Adjacency | Adj-SID sub- | [RFC8666] |		| Prefix-SID | Prefix-SID Sub-TLV (4) | [RFC8666] |
	| SID | TLV (5) | |		+-------------------+--------------------------+-----------+
	| LAN | LAN Adj-SID | [RFC8666] |		| Range | OSPFv3 Extended Prefix | [RFC8666] |
	| Adjacency | sub-TLV (6) | |		| | Range TLV (9) | |
	| SID | | |		+-------------------+--------------------------+-----------+
	| Prefix SID | Prefix SID | [RFC8666] |		| SID/Label | SID/Label Sub-TLV (7) | [RFC8666] |
	| | sub-TLV (4) | |		+-------------------+--------------------------+-----------+
	| Range | OSPFv3 | [RFC8666] |		| Prefix Attribute | Prefix Option Fields of | [RFC8362] |
	| | Extended | |		| Flags | Prefix TLV types 3,5,6 | |
	| | Prefix Range | |		+-------------------+--------------------------+-----------+
	| | TLV (9) | |		| Source OSPF | Prefix Source Router | [RFC9084] |
	| SID/Label | SID/Label | [RFC8666] |		| Router Identifier | Address Sub-TLV (28) | |
	| | sub-TLV (7) | |		+-------------------+--------------------------+-----------+
	| Prefix | Prefix | [RFC8362] |		| Source OSPF | Prefix Source OSPF | [RFC9084] |
	| Attribute | Option | |		| Router-ID | Router-ID Sub-TLV (27) | |
	| Flags | Fields of | |		+-------------------+--------------------------+-----------+
	| | Prefix TLV | |
	| | types 3,5,6 | |
	| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| Router | Source | ] |
	| Identifier | Router-ID | |
	| | sub-TLV (27) | |
	| Source OSPF | Prefix | [I-D.ietf-lsr-ospf-prefix-originator |
	| Router-ID | Source OSPF | ] |
	| | Router-ID | |
	| | sub-TLV (28) | |
	+-------------+--------------+--------------------------------------+
	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		IANA has registered the following code points in the "BGP-LS Node
	document from the registry "BGP-LS Node Descriptor, Link Descriptor,		Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs"
	Prefix Descriptor, and Attribute TLVs" under the "BGP-LS Parameters"		registry under the "Border Gateway Protocol - Link State (BGP-LS)
	registry based on Table 8. The column "IS-IS TLV/Sub-TLV" defined in		Parameter" registry based on Table 8. The column "IS-IS TLV/Sub-TLV"
	the registry does not require any value and should be left empty.		defined in 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 |		+----------------+-----------------------------+---------------+
	| 1036 | SR Local Block | Section 2.1.4 |		| 1035 | SR Algorithm | Section 2.1.3 |
	| 1037 | SRMS Preference | Section 2.1.5 |		+----------------+-----------------------------+---------------+
	| 1099 | Adjacency SID | Section 2.2.1 |		| 1036 | SR Local Block | Section 2.1.4 |
	| 1100 | LAN Adjacency SID | Section 2.2.2 |		+----------------+-----------------------------+---------------+
	| 1158 | Prefix SID | Section 2.3.1 |		| 1037 | SRMS Preference | Section 2.1.5 |
	| 1159 | Range | Section 2.3.5 |		+----------------+-----------------------------+---------------+
	| 1161 | SID/Label | Section 2.1.1 |		| 1099 | Adjacency SID | Section 2.2.1 |
	| 1170 | Prefix Attribute Flags | Section 2.3.2 |		+----------------+-----------------------------+---------------+
	| 1171 | Source Router Identifier | Section 2.3.3 |		| 1100 | LAN Adjacency SID | Section 2.2.2 |
	| 1172 | L2 Bundle Member Attributes | Section 2.2.3 |		+----------------+-----------------------------+---------------+
	| 1174 (suggested) | Source OSPF Router-ID | Section 2.3.4 |		| 1158 | Prefix-SID | Section 2.3.1 |
	+------------------+-----------------------------+---------------+		+----------------+-----------------------------+---------------+
			| 1159 | Range | Section 2.3.5 |
			+----------------+-----------------------------+---------------+
			| 1161 | SID/Label | Section 2.1.1 |
			+----------------+-----------------------------+---------------+
			| 1170 | Prefix Attribute Flags | Section 2.3.2 |
			+----------------+-----------------------------+---------------+
			| 1171 | Source Router Identifier | Section 2.3.3 |
			+----------------+-----------------------------+---------------+
			| 1172 | L2 Bundle Member Attributes | Section 2.2.3 |
			+----------------+-----------------------------+---------------+
			| 1174 | Source OSPF Router-ID | Section 2.3.4 |
			+----------------+-----------------------------+---------------+
	Table 8: Summary Table of TLV/Sub-TLV Codepoints		Table 8: Summary of TLV/Sub-TLV Code Points
	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
	affect the BGP protocol operations and management other than as		affect the BGP protocol operations and management other than as
	discussed in the Manageability Considerations section of [RFC7752].		discussed in the Manageability Considerations section of [RFC7752].
	Specifically, the malformed attribute tests for syntactic checks in		Specifically, the malformed attribute tests for syntactic checks in
	the Fault Management section of [RFC7752] now encompass the new BGP-		the Fault Management section of [RFC7752] now encompass the new BGP-
	LS Attribute TLVs defined in this document. The semantic or content		LS Attribute TLVs defined in this document. The semantic or content
	checking for the TLVs specified in this document and their		checking for the TLVs specified in this document and their
	association with the BGP-LS NLRI types or their BGP-LS Attribute is		association with the BGP-LS NLRI types or their BGP-LS Attribute is
	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 to Sections 1 and 2 of [RFC7752]). The
	of semantic or content errors by the consumer would be dictated by		handling of semantic or content errors by the consumer would be
	the nature of its application usage and hence is beyond the scope of		dictated by the nature of its application usage and hence is beyond
	this document.		the scope of 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 the BGP-LS Attribute being discarded		error in them would result in the BGP-LS Attribute being discarded
	with an error log. The SR information introduced in BGP-LS by this		with an error log. The SR information introduced in BGP-LS by this
	specification, may be used by BGP-LS consumer applications like a SR		specification may be used by BGP-LS consumer applications like an SR
	path computation engine (PCE) to learn the SR capabilities of the		Path Computation Engine (PCE) to learn the SR capabilities of the
	nodes in the topology and the mapping of SR segments to those nodes.		nodes in the topology and the mapping of SR segments to those nodes.
	This can enable the SR PCE to perform path computations based on SR		This can enable the SR PCE to perform path computations based 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.
	The extensions, specified in this document, do not introduce any new		The extensions, specified in this document, do not introduce any new
	configuration or monitoring aspects in BGP or BGP-LS other than as		configuration or monitoring aspects in BGP or BGP-LS other than as
	discussed in [RFC7752]. The manageability aspects of the underlying		discussed in [RFC7752]. The manageability aspects of the underlying
	SR features are covered by [I-D.ietf-spring-sr-yang],		SR features are covered by [RFC9020], [ISIS-SR-YANG], and
	[I-D.ietf-isis-sr-yang] and [I-D.ietf-ospf-sr-yang].		[OSPF-SR-YANG].
	5. Security Considerations		5. Security Considerations
	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].
	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 ([RFC8667], [RFC8665] and [RFC8666]). These TLVs		defined information (see [RFC8665], [RFC8666], and [RFC8667]). These
	represent the SR information associated with the IGP node, link and		TLVs represent the SR information associated with the IGP node, link,
	prefix. The IGP instances originating these TLVs are assumed to		and 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 [RFC8667], [RFC8665] and [RFC8666]) in order to prevent		described in [RFC8665], [RFC8666], and [RFC8667]) in order to prevent
	any security issue when propagating the TLVs into BGP-LS.		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		SR domain. SR operates within a trusted domain [RFC8402], and its
	[RFC8402] and its security considerations also apply to BGP-LS		security considerations also apply to BGP-LS sessions when carrying
	sessions when carrying SR information. The SR traffic engineering		SR information. The SR traffic engineering policies using the SIDs
	policies using the SIDs advertised via BGP-LS are expected to be used		advertised via BGP-LS are expected to be used entirely within this
	entirely within this trusted SR domain (e.g. between multiple AS/		trusted SR domain (e.g., between multiple ASes/domains within a
	domains within a single provider network). Therefore, precaution is		single provider network). Therefore, precaution is necessary to
	necessary to ensure that the link-state information (including SR		ensure that the link-state information (including SR information)
	information) advertised via BGP-LS sessions is limited to consumers		advertised via BGP-LS sessions is limited to consumers in a secure
	in a secure manner within this trusted SR domain. BGP peering		manner within this trusted SR domain. BGP peering sessions for
	sessions for address-families other than Link-State may be setup to		address families other than link state may be set up to routers
	routers outside the SR domain. The isolation of BGP-LS peering		outside the SR domain. The isolation of BGP-LS peering sessions is
	sessions is recommended to ensure that BGP-LS topology information		recommended to ensure that BGP-LS topology information (including the
	(including the newly added SR information) is not advertised to an		newly added SR information) is not advertised to an external BGP
	external BGP peering session outside the SR domain.		peering session outside the SR domain.
	6. Contributors
	The following people have substantially contributed to the editing of
	this document:
	Peter Psenak
	Cisco Systems
	Email: ppsenak@cisco.com
	Les Ginsberg
	Cisco Systems
	Email: ginsberg@cisco.com
	Acee Lindem
	Cisco Systems
	Email: acee@cisco.com
	Saikat Ray
	Individual
	Email: raysaikat@gmail.com
	Jeff Tantsura
	Apstra Inc.
	Email: jefftant.ietf@gmail.com
	7. Acknowledgements
	The authors would like to thank Jeffrey Haas, Aijun Wang, Robert
	Raszuk and Susan Hares for their review of this document and their
	comments. The authors would also like to thank Alvaro Retana for his
	extensive review and comments which helped correct issues and improve
	the document.
	8. References
	8.1. Normative References		6. References
	[I-D.ietf-lsr-ospf-prefix-originator]		6.1. Normative References
	Wang, A., Lindem, A., Dong, J., Psenak, P., and K.
	Talaulikar, "OSPF Prefix Originator Extensions", draft-
	ietf-lsr-ospf-prefix-originator-07 (work in progress),
	October 2020.
	[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>.
	skipping to change at page 30, line 10 ¶		skipping to change at line 1319 ¶
	Bashandy, A., Gredler, H., and B. Decraene, "IS-IS		Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
	Extensions for Segment Routing", RFC 8667,		Extensions for Segment Routing", RFC 8667,
	DOI 10.17487/RFC8667, December 2019,		DOI 10.17487/RFC8667, December 2019,
	<https://www.rfc-editor.org/info/rfc8667>.		<https://www.rfc-editor.org/info/rfc8667>.
	[RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri,		[RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri,
	M., and E. Aries, "Advertising Layer 2 Bundle Member Link		M., and E. Aries, "Advertising Layer 2 Bundle Member Link
	Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668,		Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668,
	December 2019, <https://www.rfc-editor.org/info/rfc8668>.		December 2019, <https://www.rfc-editor.org/info/rfc8668>.
	8.2. Informative References		[RFC9084] Wang, A., Lindem, A., Dong, J., Psenak, P., and K.
			Talaulikar, Ed., "OSPF Prefix Originator Extensions",
			RFC 9084, DOI 10.17487/RFC9084, August 2021,
			<https://www.rfc-editor.org/info/rfc9084>.
	[I-D.ietf-isis-sr-yang]		6.2. Informative References
			[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-09 (work in progress), January		Work in Progress, Internet-Draft, draft-ietf-isis-sr-yang-
	2021.		10, 21 February 2021,
			<https://datatracker.ietf.org/doc/html/draft-ietf-isis-sr-
			yang-10>.
	[I-D.ietf-ospf-sr-yang]		[OSPF-SR-YANG]
	Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem,		Yeung, D., Qu, Y., Zhang, J., 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-13 (work in progress), January		Work in Progress, Internet-Draft, draft-ietf-ospf-sr-yang-
	2021.		15, 2 July 2021, <https://datatracker.ietf.org/doc/html/
			draft-ietf-ospf-sr-yang-15>.
	[I-D.ietf-spring-sr-yang]
	Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J.
	Tantsura, "YANG Data Model for Segment Routing", draft-
	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.,		[RFC8661] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
	Decraene, B., and S. Litkowski, "Segment Routing MPLS		Decraene, B., and S. Litkowski, "Segment Routing MPLS
	Interworking with LDP", RFC 8661, DOI 10.17487/RFC8661,		Interworking with LDP", RFC 8661, DOI 10.17487/RFC8661,
	December 2019, <https://www.rfc-editor.org/info/rfc8661>.		December 2019, <https://www.rfc-editor.org/info/rfc8661>.
			[RFC9020] Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J.
			Tantsura, "YANG Data Model for Segment Routing", RFC 9020,
			DOI 10.17487/RFC9020, May 2021,
			<https://www.rfc-editor.org/info/rfc9020>.
			Acknowledgements
			The authors would like to thank Jeffrey Haas, Aijun Wang, Robert
			Raszuk, and Susan Hares for their review of this document and their
			comments. The authors would also like to thank Alvaro Retana for his
			extensive review and comments, which helped correct issues and
			improve the document.
			Contributors
			The following people have substantially contributed to the editing of
			this document:
			Peter Psenak
			Cisco Systems
			Email: ppsenak@cisco.com
			Les Ginsberg
			Cisco Systems
			Email: ginsberg@cisco.com
			Acee Lindem
			Cisco Systems
			Email: acee@cisco.com
			Saikat Ray
			Individual
			Email: raysaikat@gmail.com
			Jeff Tantsura
			Apstra Inc.
			Email: jefftant.ietf@gmail.com
	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
	skipping to change at page 31, line 25 ¶		skipping to change at line 1424 ¶
	Email: cfilsfil@cisco.com		Email: cfilsfil@cisco.com
	Hannes Gredler		Hannes Gredler
	RtBrick Inc.		RtBrick Inc.
	Email: hannes@rtbrick.com		Email: hannes@rtbrick.com
	Mach(Guoyi) Chen		Mach(Guoyi) Chen
	Huawei Technologies		Huawei Technologies
	Huawei Building, No. 156 Beiqing Rd.		Huawei Building, No. 156 Beiqing Rd.
	Beijing 100095		Beijing
			100095
	China		China
	Email: mach.chen@huawei.com		Email: mach.chen@huawei.com
End of changes. 216 change blocks.
	605 lines changed or deleted		647 lines changed or added
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