< draft-li-ospf-ospfv3-srv6-extensions-06.txt		draft-li-ospf-ospfv3-srv6-extensions-07.txt >
	Network Working Group Z. Li		Network Working Group Z. Li
	Internet-Draft Z. Hu		Internet-Draft Z. Hu
	Intended status: Standards Track D. Cheng		Intended status: Standards Track D. Cheng
	Expires: May 7, 2020 Huawei Technologies		Expires: May 7, 2020 Huawei Technologies
	K. Talaulikar		K. Talaulikar
	P. Psenak		P. Psenak
	Cisco Systems		Cisco Systems
	November 4, 2019		November 4, 2019
	OSPFv3 Extensions for SRv6		OSPFv3 Extensions for SRv6
	draft-li-ospf-ospfv3-srv6-extensions-06		draft-li-ospf-ospfv3-srv6-extensions-07
	Abstract		Abstract
	Segment Routing (SR) allows for a flexible definition of end-to-end		Segment Routing (SR) allows for a flexible definition of end-to-end
	paths by encoding paths as sequences of topological sub-paths, called		paths by encoding paths as sequences of topological sub-paths, called
	"segments". Segment routing architecture can be implemented over an		"segments". Segment routing architecture can be implemented over an
	MPLS data plane as well as an IPv6 data plane. This draft describes		MPLS data plane as well as an IPv6 data plane. This draft describes
	the OSPFv3 extensions required to support Segment Routing over an		the OSPFv3 extensions required to support Segment Routing over an
	IPv6 data plane (SRv6).		IPv6 data plane (SRv6).
	skipping to change at page 2, line 22 ¶		skipping to change at page 2, line 22 ¶
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. SRv6-Capabilities TLV . . . . . . . . . . . . . . . . . . . . 3		2. SRv6-Capabilities TLV . . . . . . . . . . . . . . . . . . . . 3
	3. Advertisement of Supported Algorithms . . . . . . . . . . . . 5		3. Advertisement of Supported Algorithms . . . . . . . . . . . . 5
	4. Advertisement of SRH Operation Limits . . . . . . . . . . . . 5		4. Advertisement of SRH Operation Limits . . . . . . . . . . . . 5
	5. Advertising Anycast Property . . . . . . . . . . . . . . . . 5		5. Advertisement of SRv6 Locator and End SIDs . . . . . . . . . 5
	6. Advertisement of SRv6 Locator and End SIDs . . . . . . . . . 6		6. SRv6 Locator LSA . . . . . . . . . . . . . . . . . . . . . . 6
	7. SRv6 Locator LSA . . . . . . . . . . . . . . . . . . . . . . 7		6.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 8
	7.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 9		7. Advertisment of SRv6 End SIDs . . . . . . . . . . . . . . . . 10
	8. Advertisment of SRv6 End SIDs . . . . . . . . . . . . . . . . 11		8. Advertisment of SRv6 SIDs Associated with Adjacencies . . . . 11
	9. Advertisment of SRv6 SIDs Associated with Adjacencies . . . . 12		8.1. SRv6 End.X SID Sub-TLV . . . . . . . . . . . . . . . . . 12
	9.1. SRv6 End.X SID Sub-TLV . . . . . . . . . . . . . . . . . 13		8.2. SRv6 LAN End.X SID Sub-TLV . . . . . . . . . . . . . . . 14
	9.2. SRv6 LAN End.X SID Sub-TLV . . . . . . . . . . . . . . . 15		9. SRv6 SID Structure sub-TLV . . . . . . . . . . . . . . . . . 15
	10. SRv6 SID Structure sub-TLV . . . . . . . . . . . . . . . . . 16		10. Security Considerations . . . . . . . . . . . . . . . . . . . 16
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 17		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
	12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17		11.1. OSPF Router Information TLVs . . . . . . . . . . . . . . 17
	12.1. OSPF Router Information TLVs . . . . . . . . . . . . . . 18		11.2. OSPFv3 LSA Function Codes . . . . . . . . . . . . . . . 17
	12.2. OSPFv3 LSA Function Codes . . . . . . . . . . . . . . . 18		11.3. OSPFv3 Extended-LSA sub-TLVs . . . . . . . . . . . . . . 17
	12.3. OSPFv3 Extended-LSA sub-TLVs . . . . . . . . . . . . . . 18		11.4. OSPFv3 Locator LSA TLVs . . . . . . . . . . . . . . . . 17
	12.4. OSPFv3 Locator LSA TLVs . . . . . . . . . . . . . . . . 18		11.5. OSPFv3 Locator LSA sub-TLVs . . . . . . . . . . . . . . 18
	12.5. OSPFv3 Locator LSA sub-TLVs . . . . . . . . . . . . . . 19		12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
	12.6. Prefix Attribute bits Option . . . . . . . . . . . . . . 19		13. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
	13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20		13.1. Normative References . . . . . . . . . . . . . . . . . . 19
	14. References . . . . . . . . . . . . . . . . . . . . . . . . . 20		13.2. Informative References . . . . . . . . . . . . . . . . . 20
	14.1. Normative References . . . . . . . . . . . . . . . . . . 20		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
	14.2. Informative References . . . . . . . . . . . . . . . . . 21
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
	1. Introduction		1. Introduction
	Segment Routing (SR) architecture [RFC8402] specifies how a node can		Segment Routing (SR) architecture [RFC8402] specifies how a node can
	steer a packet through an ordered list of instructions, called		steer a packet through an ordered list of instructions, called
	segments. These segments are identified through Segment Identifiers		segments. These segments are identified through Segment Identifiers
	(SIDs).		(SIDs).
	Segment Routing can be instantiated on the IPv6 data plane through		Segment Routing can be instantiated on the IPv6 data plane through
	the use of the Segment Routing Header (SRH) defined in		the use of the Segment Routing Header (SRH) defined in
	skipping to change at page 5, line 44 ¶		skipping to change at page 5, line 33 ¶
	advertised using the Node MSD TLV in the OSPFv3 Router Information		advertised using the Node MSD TLV in the OSPFv3 Router Information
	LSA [RFC7770] while Link MSDs are advertised using the Link MSD sub-		LSA [RFC7770] while Link MSDs are advertised using the Link MSD sub-
	TLV of the E-Router-LSA TLV [RFC8362]. The format of the MSD types		TLV of the E-Router-LSA TLV [RFC8362]. The format of the MSD types
	for OSPFv3 is defined in [RFC8476].		for OSPFv3 is defined in [RFC8476].
	The MSD types for SRv6 that are defined in		The MSD types for SRv6 that are defined in
	[I-D.ietf-lsr-isis-srv6-extensions] for IS-IS are also used by		[I-D.ietf-lsr-isis-srv6-extensions] for IS-IS are also used by
	OSPFv3. These MSD Types are allocated under the IGP MSD Types		OSPFv3. These MSD Types are allocated under the IGP MSD Types
	registry maintained by IANA that are shared by IS-IS and OSPF.		registry maintained by IANA that are shared by IS-IS and OSPF.
	5. Advertising Anycast Property		5. Advertisement of SRv6 Locator and End SIDs
	Both prefixes and SRv6 Locators may be configured as anycast and as
	such the same value can be advertised by multiple routers. It is
	useful for other routers to know that the advertisement is for an
	anycast identifier.
	A new bit in "Bit Values for prefix options" registry [RFC5340] is
	defined to advertise the anycast property:
	Bit #: 1 (Suggested - to be assigned by IANA) Name: Anycast Bit
	(A-bit)
	When the prefix/SRv6 locator is configured as anycast, the A-bit
	SHOULD be set. Otherwise, this A-bit MUST be clear.
	The A-bit MUST be preserved when leaked between areas.
	The A-bit and the N-bit MUST NOT both be set.
	If both N-bit and A-bit are set in the prefix/SRv6 Locator
	advertisement, the receiving routers MUST ignore the N-bit.
	The same prefix/SRv6 Locator can be advertised by multiple routers.
	If at least one of them sets the A-bit in its advertisement, the
	prefix/SRv6 Locator SHOULD be considered as anycast.
	6. Advertisement of SRv6 Locator and End SIDs
	An SRv6 Segment Identifier (SID) is 128 bits and represented as		An SRv6 Segment Identifier (SID) is 128 bits and represented as
	LOC:FUNCT as described in [I-D.ietf-spring-srv6-network-programming].		LOC:FUNCT as described in [I-D.ietf-spring-srv6-network-programming].
	A node is provisioned with algorithm specific locators for each		A node is provisioned with algorithm specific locators for each
	algorithm supported by that node. Each locator is a covering prefix		algorithm supported by that node. Each locator is a covering prefix
	for all SIDs provisioned on that node which have the matching		for all SIDs provisioned on that node which have the matching
	algorithm.		algorithm.
	Locators MUST be advertised in the SRv6 Locator LSA (see Section 7).		Locators MUST be advertised in the SRv6 Locator LSA (see Section 6).
	Forwarding entries for the locators advertised in the SRv6 Locator		Forwarding entries for the locators advertised in the SRv6 Locator
	LSA MUST be installed in the forwarding plane of receiving SRv6		LSA MUST be installed in the forwarding plane of receiving SRv6
	capable routers when the associated algorithm is supported by the		capable routers when the associated algorithm is supported by the
	receiving node. Locators can be of different route types similar to		receiving node. Locators can be of different route types similar to
	existing OSPF LSA route types - Intra-Area, Inter-Area, External and		existing OSPF LSA route types - Intra-Area, Inter-Area, External and
	NSSA. The computation of locator reachability and their		NSSA. The computation of locator reachability and their
	advertisement are similar to how normal OSPF prefix reachability LSAs		advertisement are similar to how normal OSPF prefix reachability LSAs
	are processed as part of the SPF computation.		are processed as part of the SPF computation.
	Locators are routable and MAY also be advertised via Prefix LSAs of		Locators are routable and MAY also be advertised via Prefix LSAs of
	skipping to change at page 7, line 25 ¶		skipping to change at page 6, line 34 ¶
	SRv6 SIDs are not directly routable and MUST NOT be installed in the		SRv6 SIDs are not directly routable and MUST NOT be installed in the
	forwarding plane. Reachability to SRv6 SIDs depends upon the		forwarding plane. Reachability to SRv6 SIDs depends upon the
	existence of a covering locator. Adherence to the rules defined in		existence of a covering locator. Adherence to the rules defined in
	this section will assure that SRv6 SIDs associated with a supported		this section will assure that SRv6 SIDs associated with a supported
	algorithm will be forwarded correctly, while SRv6 SIDs associated		algorithm will be forwarded correctly, while SRv6 SIDs associated
	with an unsupported algorithm will be dropped. NOTE: The drop		with an unsupported algorithm will be dropped. NOTE: The drop
	behavior depends on the absence of a default/summary route covering a		behavior depends on the absence of a default/summary route covering a
	given locator.		given locator.
	7. SRv6 Locator LSA		6. SRv6 Locator LSA
	The SRv6 Locator LSA has a function code of TBD while the S1/S2 bits		The SRv6 Locator LSA has a function code of TBD while the S1/S2 bits
	are dependent on the desired flooding scope for the LSA. The		are dependent on the desired flooding scope for the LSA. The
	flooding scope of the SRv6 Locator LSA depends on the scope of the		flooding scope of the SRv6 Locator LSA depends on the scope of the
	advertised SRv6 Locator and is under the control of the advertising		advertised SRv6 Locator and is under the control of the advertising
	router. The U bit will be set indicating that the LSA should be		router. The U bit will be set indicating that the LSA should be
	flooded even if it is not understood.		flooded even if it is not understood.
	Multiple SRv6 Locator LSAs can be advertised by an OSPFv3 router and		Multiple SRv6 Locator LSAs can be advertised by an OSPFv3 router and
	they are distinguished by their Link State IDs (which are chosen		they are distinguished by their Link State IDs (which are chosen
	skipping to change at page 9, line 5 ¶		skipping to change at page 8, line 5 ¶
	The Length field defines the length of the value portion in octets		The Length field defines the length of the value portion in octets
	(thus, a TLV with no value portion would have a length of 0). The		(thus, a TLV with no value portion would have a length of 0). The
	TLV is padded to 4-octet alignment; padding is not included in the		TLV is padded to 4-octet alignment; padding is not included in the
	Length field (so a 3-octet value would have a length of 3, but the		Length field (so a 3-octet value would have a length of 3, but the
	total size of the TLV would be 8 octets). Nested TLVs are also		total size of the TLV would be 8 octets). Nested TLVs are also
	32-bit aligned. For example, a 1-byte value would have the Length		32-bit aligned. For example, a 1-byte value would have the Length
	field set to 1, and 3 octets of padding would be added to the end of		field set to 1, and 3 octets of padding would be added to the end of
	the value portion of the TLV. The padding is composed of zeros.		the value portion of the TLV. The padding is composed of zeros.
	7.1. SRv6 Locator TLV		6.1. SRv6 Locator TLV
	The SRv6 Locator TLV is a top-level TLV of the SRv6 Locator LSA that		The SRv6 Locator TLV is a top-level TLV of the SRv6 Locator LSA that
	is used to advertise a SRv6 Locator, its attributes and SIDs		is used to advertise a SRv6 Locator, its attributes and SIDs
	associated with it. Multiple SRv6 Locator TLVs MAY be advertised in		associated with it. Multiple SRv6 Locator TLVs MAY be advertised in
	each SRv6 Locator LSA. However, since the S12 bits define the		each SRv6 Locator LSA. However, since the S12 bits define the
	flooding scope, the LSA flooding scope MUST satisfy the application-		flooding scope, the LSA flooding scope MUST satisfy the application-
	specific requirements for all the locators included in a single SRv6		specific requirements for all the locators included in a single SRv6
	Locator LSA.		Locator LSA.
	When multiple SRv6 Locator TLVs are received from a given router in a		When multiple SRv6 Locator TLVs are received from a given router in a
	skipping to change at page 10, line 31 ¶		skipping to change at page 9, line 31 ¶
	Algorithm: 8 bit field. Associated algorithm. Algorithm values		Algorithm: 8 bit field. Associated algorithm. Algorithm values
	are defined in the IGP Algorithm Type registry.		are defined in the IGP Algorithm Type registry.
	Locator Length: 8 bit field. Carries the length of the Locator		Locator Length: 8 bit field. Carries the length of the Locator
	prefix as number of bits (1-128).		prefix as number of bits (1-128).
	Flags: 8 bit field. The following flags are defined		Flags: 8 bit field. The following flags are defined
	0 1 2 3 4 5 6 7		0 1 2 3 4 5 6 7
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	|N| Reserved |		|N|A| Reserved |
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	Figure 5		Figure 5
	* N flag : When the locator uniquely identifies a node in the		* N flag : When the locator uniquely identifies a node in the
	network (i.e. it is provisioned on one and only one node), the		network (i.e. it is provisioned on one and only one node), the
	N bit MUST be set. Otherwise, this bit MUST be clear.		N bit MUST be set. Otherwise, this bit MUST be clear.
			* A bit : When the Locator is configured as anycast, the A bit
			SHOULD be set. Otherwise, this bit MUST be clear.
	* Other flags are not defined and SHOULD be set to 0 and MUST be		* Other flags are not defined and SHOULD be set to 0 and MUST be
	ignored on receipt.		ignored on receipt.
	Metric : 32 bit field. The metric value associated with the		Metric : 32 bit field. The metric value associated with the
	locator.		locator.
	Locator : 16 octets. This field encodes the advertised SRv6		Locator : 16 octets. This field encodes the advertised SRv6
	Locator.		Locator.
	Sub-TLVs : Used to advertise sub-TLVs that provide additional		Sub-TLVs : Used to advertise sub-TLVs that provide additional
	attributes for the given SRv6 Locator and SRv6 SIDs associated		attributes for the given SRv6 Locator and SRv6 SIDs associated
	with it.		with it.
	8. Advertisment of SRv6 End SIDs		7. Advertisment of SRv6 End SIDs
	SRv6 End SID sub-TLV is a new sub-TLV of SRv6 Locator TLV in the SRv6		SRv6 End SID sub-TLV is a new sub-TLV of SRv6 Locator TLV in the SRv6
	Locator LSA (defined in Section 7). It is used to advertise the SRv6		Locator LSA (defined in Section 6). It is used to advertise the SRv6
	SIDs belonging to the node along with their associated functions.		SIDs belonging to the node along with their associated functions.
	SIDs associated with adjacencies are advertised as described in		SIDs associated with adjacencies are advertised as described in
	Section 9. Every SRv6 enabled OSPFv3 router SHOULD advertise at		Section 8. Every SRv6 enabled OSPFv3 router SHOULD advertise at
	least one SRv6 SID associated with an END behavior for its node as		least one SRv6 SID associated with an END behavior for its node as
	specified in [I-D.ietf-spring-srv6-network-programming].		specified in [I-D.ietf-spring-srv6-network-programming].
	SRv6 End SIDs inherit the algorithm from the parent locator. The		SRv6 End SIDs inherit the algorithm from the parent locator. The
	SRv6 End SID MUST be a subnet of the associated Locator. SRv6 End		SRv6 End SID MUST be a subnet of the associated Locator. SRv6 End
	SIDs which are NOT a subnet of the associated locator MUST be		SIDs which are NOT a subnet of the associated locator MUST be
	ignored.		ignored.
	The router MAY advertise multiple instances of the SRv6 End SID sub-		The router MAY advertise multiple instances of the SRv6 End SID sub-
	TLV within the SRv6 Locator TLV - one for each of the SRv6 SIDs to be		TLV within the SRv6 Locator TLV - one for each of the SRv6 SIDs to be
	skipping to change at page 12, line 28 ¶		skipping to change at page 11, line 28 ¶
	Endpoint Behavior ID: 16 bit field. The endpoint behavior code		Endpoint Behavior ID: 16 bit field. The endpoint behavior code
	point for this SRv6 SID as defined in		point for this SRv6 SID as defined in
	[I-D.ietf-spring-srv6-network-programming].		[I-D.ietf-spring-srv6-network-programming].
	SID : 16 octets. This field encodes the advertised SRv6 SID.		SID : 16 octets. This field encodes the advertised SRv6 SID.
	Sub-Sub-TLVs : Used to advertise sub-sub-TLVs that provide		Sub-Sub-TLVs : Used to advertise sub-sub-TLVs that provide
	additional attributes for the given SRv6 SID.		additional attributes for the given SRv6 SID.
	9. Advertisment of SRv6 SIDs Associated with Adjacencies		8. Advertisment of SRv6 SIDs Associated with Adjacencies
	The SRv6 endpoint behaviors are defined in		The SRv6 endpoint behaviors are defined in
	[I-D.ietf-spring-srv6-network-programming] include certain behaviors		[I-D.ietf-spring-srv6-network-programming] include certain behaviors
	which are specific to links or adjacencies. The most basic of this		which are specific to links or adjacencies. The most basic of this
	which is critical for link state routing protocols like OSPFv3 is the		which is critical for link state routing protocols like OSPFv3 is the
	End.X behavior that is an instruction to forward to a specific		End.X behavior that is an instruction to forward to a specific
	neighbor on a specific link. These SRv6 SIDs along with others that		neighbor on a specific link. These SRv6 SIDs along with others that
	are defined in [I-D.ietf-spring-srv6-network-programming] which are		are defined in [I-D.ietf-spring-srv6-network-programming] which are
	specific to links or adjacencies need to be advertised by OSPFv3 so		specific to links or adjacencies need to be advertised by OSPFv3 so
	that this information is available with all routers in the area to		that this information is available with all routers in the area to
	skipping to change at page 13, line 21 ¶		skipping to change at page 12, line 21 ¶
	End.X function for a single neighbor. The same SRv6 SID MAY be		End.X function for a single neighbor. The same SRv6 SID MAY be
	advertised for the End.X function corresponding to more than one		advertised for the End.X function corresponding to more than one
	neighbor. Thus multiple instances of the SRv6 End.X SID and SRv6 LAN		neighbor. Thus multiple instances of the SRv6 End.X SID and SRv6 LAN
	End.X SID sub-TLVs MAY be advertised within the E-Router-Link TLV for		End.X SID sub-TLVs MAY be advertised within the E-Router-Link TLV for
	a single link.		a single link.
	All End.X SIDs MUST be a subnet of a Locator with matching algorithm		All End.X SIDs MUST be a subnet of a Locator with matching algorithm
	which is advertised by the same node in an SRv6 Locator TLV. End.X		which is advertised by the same node in an SRv6 Locator TLV. End.X
	SIDs which do not meet this requirement MUST be ignored.		SIDs which do not meet this requirement MUST be ignored.
	9.1. SRv6 End.X SID Sub-TLV		8.1. SRv6 End.X SID Sub-TLV
	The format of the SRv6 End.X SID sub-TLV is shown below		The format of the SRv6 End.X SID sub-TLV is shown below
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Endpoint Behaviour ID | Flags | Reserved1 |		| Endpoint Behaviour ID | Flags | Reserved1 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 15, line 5 ¶		skipping to change at page 14, line 5 ¶
	defined in [RFC8402].		defined in [RFC8402].
	Reserved2 : 16 bit field. Should be set to 0 and MUST be ignored		Reserved2 : 16 bit field. Should be set to 0 and MUST be ignored
	on receipt.		on receipt.
	SID: 16 octets. This field encodes the advertised SRv6 SID.		SID: 16 octets. This field encodes the advertised SRv6 SID.
	Sub-TLVs : Used to advertise sub-TLVs that provide additional		Sub-TLVs : Used to advertise sub-TLVs that provide additional
	attributes for the given SRv6 End.X SID.		attributes for the given SRv6 End.X SID.
	9.2. SRv6 LAN End.X SID Sub-TLV		8.2. SRv6 LAN End.X SID Sub-TLV
	The format of the SRv6 LAN End.X SID sub-TLV is as shown below		The format of the SRv6 LAN End.X SID sub-TLV is as shown below
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Endpoint Behaviour | Flags | Reserved1 |		| Endpoint Behaviour | Flags | Reserved1 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 16, line 38 ¶		skipping to change at page 15, line 38 ¶
	o Reserved2 : 16 bit field. Should be set to 0 and MUST be ignored		o Reserved2 : 16 bit field. Should be set to 0 and MUST be ignored
	on receipt.		on receipt.
	o Neighbor ID : 4 octets of OSPFv3 Router-id of the neighbor		o Neighbor ID : 4 octets of OSPFv3 Router-id of the neighbor
	o SID: 16 octets. This field encodes the advertised SRv6 SID.		o SID: 16 octets. This field encodes the advertised SRv6 SID.
	o Sub-TLVs : Used to advertise sub-TLVs that provide additional		o Sub-TLVs : Used to advertise sub-TLVs that provide additional
	attributes for the given SRv6 SID.		attributes for the given SRv6 SID.
	10. SRv6 SID Structure sub-TLV		9. SRv6 SID Structure sub-TLV
	SRv6 SID Structure sub-TLV is used to advertise the length of each		SRv6 SID Structure sub-TLV is used to advertise the length of each
	individual part of the SRv6 SID as defined in		individual part of the SRv6 SID as defined in
	[I-D.ietf-spring-srv6-network-programming]. It is used as an		[I-D.ietf-spring-srv6-network-programming]. It is used as an
	optional sub-sub-TLV of the following:		optional sub-sub-TLV of the following:
	o SRv6 End SID sub-TLV (refer Section 8)		o SRv6 End SID sub-TLV (refer Section 7)
	o SRv6 End.X SID sub-TLV (refer Section 9.1)		o SRv6 End.X SID sub-TLV (refer Section 8.1)
	o SRv6 LAN End.X SID sub-TLV (refer Section 9.2)		o SRv6 LAN End.X SID sub-TLV (refer Section 8.2)
	The sub-TLV has the following format:		The sub-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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| LB Length | LN Length | Fun. Length | Arg. Length |		| LB Length | LN Length | Fun. Length | Arg. Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 7: SRv6 SID Structure sub-TLV		Figure 7: SRv6 SID Structure sub-TLV
	Where:		Where:
	Type: 2 octet field with value TBD, see Section 12.		Type: 2 octet field with value TBD, see Section 11.
	Length: 2 octet field with the value 4.		Length: 2 octet field with the value 4.
	LB Length: 1 octet field. SRv6 SID Locator Block length in bits.		LB Length: 1 octet field. SRv6 SID Locator Block length in bits.
	LN Length: 1 octet field. SRv6 SID Locator Node length in bits.		LN Length: 1 octet field. SRv6 SID Locator Node length in bits.
	Function Length: 1 octet field. SRv6 SID Function length in bits.		Function Length: 1 octet field. SRv6 SID Function length in bits.
	Argument Length: 1 octet field. SRv6 SID Argument length in bits.		Argument Length: 1 octet field. SRv6 SID Argument length in bits.
	11. Security Considerations		10. Security Considerations
	Existing security extensions as described in [RFC5340] and [RFC8362]		Existing security extensions as described in [RFC5340] and [RFC8362]
	apply to these SRv6 extensions. While OSPFv3 is under a single		apply to these SRv6 extensions. While OSPFv3 is under a single
	administrative domain, there can be deployments where potential		administrative domain, there can be deployments where potential
	attackers have access to one or more networks in the OSPFv3 routing		attackers have access to one or more networks in the OSPFv3 routing
	domain. In these deployments, stronger authentication mechanisms		domain. In these deployments, stronger authentication mechanisms
	such as those specified in [RFC4552] SHOULD be used.		such as those specified in [RFC4552] SHOULD be used.
	Implementations MUST assure that malformed TLV and Sub-TLV defined in		Implementations MUST assure that malformed TLV and Sub-TLV defined in
	this document are detected and do not provide a vulnerability for		this document are detected and do not provide a vulnerability for
	attackers to crash the OSPFv3 router or routing process. Reception		attackers to crash the OSPFv3 router or routing process. Reception
	of malformed TLV or Sub-TLV SHOULD be counted and/or logged for		of malformed TLV or Sub-TLV SHOULD be counted and/or logged for
	further analysis. Logging of malformed TLVs and Sub-TLVs SHOULD be		further analysis. Logging of malformed TLVs and Sub-TLVs SHOULD be
	rate-limited to prevent a Denial of Service (DoS) attack (distributed		rate-limited to prevent a Denial of Service (DoS) attack (distributed
	or otherwise) from overloading the OSPFv3 control plane.		or otherwise) from overloading the OSPFv3 control plane.
	12. IANA Considerations		11. IANA Considerations
	This document specifies updates to multiple OSPF and OSPFv3 related		This document specifies updates to multiple OSPF and OSPFv3 related
	IANA registries as follows.		IANA registries as follows.
	12.1. OSPF Router Information TLVs		11.1. OSPF Router Information TLVs
	This document proposes the following new code point in the "OSPF		This document proposes the following new code point in the "OSPF
	Router Information (RI) TLVs" registry under the "OSPF Parameters"		Router Information (RI) TLVs" registry under the "OSPF Parameters"
	registry for the new TLVs:		registry for the new TLVs:
	Type TBD (suggested 17): SRv6-Capabilities TLV: Refer to		Type TBD (suggested 17): SRv6-Capabilities TLV: Refer to
	Section 2.		Section 2.
	12.2. OSPFv3 LSA Function Codes		11.2. OSPFv3 LSA Function Codes
	This document proposes the following new code point in the "OSPFv3		This document proposes the following new code point in the "OSPFv3
	LSA Function Codes" registry under the "OSPFv3 Parameters" registry		LSA Function Codes" registry under the "OSPFv3 Parameters" registry
	for the new SRv6 Locator LSA:		for the new SRv6 Locator LSA:
	o Type TBD (suggested 42): SRv6 Locator LSA: Refer to Section 7.		o Type TBD (suggested 42): SRv6 Locator LSA: Refer to Section 6.
	12.3. OSPFv3 Extended-LSA sub-TLVs		11.3. OSPFv3 Extended-LSA sub-TLVs
	This document proposes the following new code points in the "OSPFv3		This document proposes the following new code points in the "OSPFv3
	Extended-LSA Sub-TLVs" registry under the "OSPFv3 Parameters"		Extended-LSA Sub-TLVs" registry under the "OSPFv3 Parameters"
	registry for the new sub-TLVs:		registry for the new sub-TLVs:
	o Type TBD (suggested 10): SRv6 SID Structure Sub-TLV : Refer to		o Type TBD (suggested 10): SRv6 SID Structure Sub-TLV : Refer to
	Section 10.		Section 9.
	o Type TBD (suggested 11): SRv6 End.X SID Sub-TLV : Refer to		o Type TBD (suggested 11): SRv6 End.X SID Sub-TLV : Refer to
	Section 9.1.		Section 8.1.
	o Type TBD (suggested 12): SRv6 LAN End.X SID Sub-TLV : Refer to		o Type TBD (suggested 12): SRv6 LAN End.X SID Sub-TLV : Refer to
	Section 9.2.		Section 8.2.
	12.4. OSPFv3 Locator LSA TLVs		11.4. OSPFv3 Locator LSA TLVs
	This document proposes setting up of a new "OSPFv3 Locator LSA TLVs"		This document proposes setting up of a new "OSPFv3 Locator LSA TLVs"
	registry that defines top-level TLVs for the OSPFv3 SRv6 Locator LSA		registry that defines top-level TLVs for the OSPFv3 SRv6 Locator LSA
	to be added under the "OSPFv3 Parameters" registry. The initial		to be added under the "OSPFv3 Parameters" registry. The initial
	code-points assignment is as below:		code-points assignment is as below:
	o Type 0: Reserved.		o Type 0: Reserved.
	o Type 1: SRv6 Locator TLV : Refer to Section 7.1.		o Type 1: SRv6 Locator TLV : Refer to Section 6.1.
	Types in the range 2-32767 are allocated via IETF Review or IESG		Types in the range 2-32767 are allocated via IETF Review or IESG
	Approval [RFC8126].		Approval [RFC8126].
	Types in the range 32768-33023 are Reserved for Experimental Use;		Types in the range 32768-33023 are Reserved for Experimental Use;
	these will not be registered with IANA and MUST NOT be mentioned by		these will not be registered with IANA and MUST NOT be mentioned by
	RFCs.		RFCs.
	Types in the range 33024-45055 are to be assigned on a First Come		Types in the range 33024-45055 are to be assigned on a First Come
	First Served (FCFS) basis.		First Served (FCFS) basis.
	Types in the range 45056-65535 are not to be assigned at this time.		Types in the range 45056-65535 are not to be assigned at this time.
	Before any assignments can be made in the 33024-65535 range, there		Before any assignments can be made in the 33024-65535 range, there
	MUST be an IETF specification that specifies IANA Considerations that		MUST be an IETF specification that specifies IANA Considerations that
	cover the range being assigned.		cover the range being assigned.
	12.5. OSPFv3 Locator LSA sub-TLVs		11.5. OSPFv3 Locator LSA sub-TLVs
	This document proposes setting up of a new "OSPFv3 Locator LSA Sub-		This document proposes setting up of a new "OSPFv3 Locator LSA Sub-
	TLVs" registry that defines sub-TLVs at any level of nesting for the		TLVs" registry that defines sub-TLVs at any level of nesting for the
	SRv6 Locator TLVs to be added under the "OSPFv3 Parameters" registry.		SRv6 Locator TLVs to be added under the "OSPFv3 Parameters" registry.
	The initial code-points assignment is as below:		The initial code-points assignment is as below:
	o Type 0: Reserved.		o Type 0: Reserved.
	o Type 1: SRv6 End SID sub-TLV : Refer to Section 8.		o Type 1: SRv6 End SID sub-TLV : Refer to Section 7.
	o Type 10: SRv6 SID Structure Sub-TLV : Refer to Section 10.		o Type 10: SRv6 SID Structure Sub-TLV : Refer to Section 9.
	Types in the range 2-9 and 11-32767 are allocated via IETF Review or		Types in the range 2-9 and 11-32767 are allocated via IETF Review or
	IESG Approval [RFC8126].		IESG Approval [RFC8126].
	Types in the range 32768-33023 are Reserved for Experimental Use;		Types in the range 32768-33023 are Reserved for Experimental Use;
	these will not be registered with IANA and MUST NOT be mentioned by		these will not be registered with IANA and MUST NOT be mentioned by
	RFCs.		RFCs.
	Types in the range 33024-45055 are to be assigned on a First Come		Types in the range 33024-45055 are to be assigned on a First Come
	First Served (FCFS) basis.		First Served (FCFS) basis.
	Types in the range 45056-65535 are not to be assigned at this time.		Types in the range 45056-65535 are not to be assigned at this time.
	Before any assignments can be made in the 33024-65535 range, there		Before any assignments can be made in the 33024-65535 range, there
	MUST be an IETF specification that specifies IANA Considerations that		MUST be an IETF specification that specifies IANA Considerations that
	cover the range being assigned.		cover the range being assigned.
	12.6. Prefix Attribute bits Option		12. Acknowledgements
	This document adds a new bit in the "Bit Values for prefix options"
	registry:
	Bit #: 1
	Description: A bit
	Reference: Refer to Section 5.
	13. Acknowledgements
	The authors would like to thank Chenzichao for their review and		The authors would like to thank Chenzichao for their review and
	comments on this document.		comments on this document.
	14. References		13. References
	14.1. Normative References		13.1. Normative References
	[I-D.ali-spring-srv6-oam]		[I-D.ali-spring-srv6-oam]
	Ali, Z., Filsfils, C., Kumar, N., Pignataro, C.,		Ali, Z., Filsfils, C., Kumar, N., Pignataro, C.,
	faiqbal@cisco.com, f., Gandhi, R., Leddy, J., Matsushima,		faiqbal@cisco.com, f., Gandhi, R., Leddy, J., Matsushima,
	S., Raszuk, R., daniel.voyer@bell.ca, d., Dawra, G.,		S., Raszuk, R., daniel.voyer@bell.ca, d., Dawra, G.,
	Peirens, B., Chen, M., and G. Naik, "Operations,		Peirens, B., Chen, M., and G. Naik, "Operations,
	Administration, and Maintenance (OAM) in Segment Routing		Administration, and Maintenance (OAM) in Segment Routing
	Networks with IPv6 Data plane (SRv6)", draft-ali-spring-		Networks with IPv6 Data plane (SRv6)", draft-ali-spring-
	srv6-oam-02 (work in progress), October 2018.		srv6-oam-02 (work in progress), October 2018.
	[I-D.ietf-6man-segment-routing-header]		[I-D.ietf-6man-segment-routing-header]
	Filsfils, C., Dukes, D., Previdi, S., Leddy, J.,		Filsfils, C., Dukes, D., Previdi, S., Leddy, J.,
	Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header		Matsushima, S., and d. daniel.voyer@bell.ca, "IPv6 Segment
	(SRH)", draft-ietf-6man-segment-routing-header-26 (work in		Routing Header (SRH)", draft-ietf-6man-segment-routing-
	progress), October 2019.		header-22 (work in progress), November 2019.
	[I-D.ietf-lsr-isis-srv6-extensions]		[I-D.ietf-lsr-isis-srv6-extensions]
	Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and		Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and
	Z. Hu, "IS-IS Extension to Support Segment Routing over		Z. Hu, "IS-IS Extension to Support Segment Routing over
	IPv6 Dataplane", draft-ietf-lsr-isis-srv6-extensions-02		IPv6 Dataplane", draft-ietf-lsr-isis-srv6-extensions-02
	(work in progress), July 2019.		(work in progress), July 2019.
	[I-D.ietf-ospf-ospfv3-segment-routing-extensions]		[I-D.ietf-ospf-ospfv3-segment-routing-extensions]
	Psenak, P. and S. Previdi, "OSPFv3 Extensions for Segment		Psenak, P. and S. Previdi, "OSPFv3 Extensions for Segment
	Routing", draft-ietf-ospf-ospfv3-segment-routing-		Routing", draft-ietf-ospf-ospfv3-segment-routing-
	extensions-23 (work in progress), January 2019.		extensions-23 (work in progress), January 2019.
	[I-D.ietf-ospf-segment-routing-extensions]		[I-D.ietf-ospf-segment-routing-extensions]
	Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,		Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
	Shakir, R., Henderickx, W., and J. Tantsura, "OSPF		Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
	Extensions for Segment Routing", draft-ietf-ospf-segment-		Extensions for Segment Routing", draft-ietf-ospf-segment-
	routing-extensions-27 (work in progress), December 2018.		routing-extensions-27 (work in progress), December 2018.
	[I-D.ietf-spring-srv6-network-programming]		[I-D.ietf-spring-srv6-network-programming]
	Filsfils, C., Camarillo, P., Leddy, J., Voyer, D.,		Filsfils, C., Camarillo, P., Leddy, J.,
	Matsushima, S., and Z. Li, "SRv6 Network Programming",		daniel.voyer@bell.ca, d., Matsushima, S., and Z. Li, "SRv6
	draft-ietf-spring-srv6-network-programming-05 (work in		Network Programming", draft-ietf-spring-srv6-network-
	progress), October 2019.		programming-01 (work in progress), July 2019.
	[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>.
	[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality		[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality
	for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,		for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
	<https://www.rfc-editor.org/info/rfc4552>.		<https://www.rfc-editor.org/info/rfc4552>.
	skipping to change at page 21, line 47 ¶		skipping to change at page 20, line 42 ¶
	[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,		[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
	Decraene, B., Litkowski, S., and R. Shakir, "Segment		Decraene, B., Litkowski, S., and R. Shakir, "Segment
	Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,		Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
	July 2018, <https://www.rfc-editor.org/info/rfc8402>.		July 2018, <https://www.rfc-editor.org/info/rfc8402>.
	[RFC8476] Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,		[RFC8476] Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,
	"Signaling Maximum SID Depth (MSD) Using OSPF", RFC 8476,		"Signaling Maximum SID Depth (MSD) Using OSPF", RFC 8476,
	DOI 10.17487/RFC8476, December 2018,		DOI 10.17487/RFC8476, December 2018,
	<https://www.rfc-editor.org/info/rfc8476>.		<https://www.rfc-editor.org/info/rfc8476>.
	14.2. Informative References		13.2. Informative References
	[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering		[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
	(TE) Extensions to OSPF Version 2", RFC 3630,		(TE) Extensions to OSPF Version 2", RFC 3630,
	DOI 10.17487/RFC3630, September 2003,		DOI 10.17487/RFC3630, September 2003,
	<https://www.rfc-editor.org/info/rfc3630>.		<https://www.rfc-editor.org/info/rfc3630>.
	Authors' Addresses		Authors' Addresses
	Zhenbin Li		Zhenbin Li
	Huawei Technologies		Huawei Technologies
End of changes. 41 change blocks.
	103 lines changed or deleted		66 lines changed or added
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