< draft-ietf-bier-ospf-bier-extensions-01.txt		draft-ietf-bier-ospf-bier-extensions-02.txt >
	OSPF P. Psenak, Ed.		OSPF P. Psenak, Ed.
	Internet-Draft N. Kumar		Internet-Draft N. Kumar
	Intended status: Standards Track IJ. Wijnands		Intended status: Standards Track IJ. Wijnands
	Expires: April 21, 2016 Cisco		Expires: September 22, 2016 Cisco
	A. Dolganow		A. Dolganow
	Alcatel-Lucent		Alcatel-Lucent
	T. Przygienda		T. Przygienda
	Ericsson		Ericsson
	J. Zhang		J. Zhang
	Juniper Networks, Inc.		Juniper Networks, Inc.
	S. Aldrin		S. Aldrin
	Google, Inc.		Google, Inc.
	October 19, 2015		March 21, 2016
	OSPF Extensions For BIER		OSPF Extensions for BIER
	draft-ietf-bier-ospf-bier-extensions-01.txt		draft-ietf-bier-ospf-bier-extensions-02.txt
	Abstract		Abstract
	Bit Index Explicit Replication (BIER) is an architecture that		Bit Index Explicit Replication (BIER) is an architecture that
	provides optimal multicast forwarding through a "BIER domain" without		provides multicast forwarding through a "BIER domain" without
	requiring intermediate routers to maintain any multicast related per-		requiring intermediate routers to maintain multicast related per-flow
	flow state. BIER also does not require any explicit tree-building		state. Neither does BIER require an explicit tree-building protocol
	protocol for its operation. A multicast data packet enters a BIER		for its operation. A multicast data packet enters a BIER domain at a
	domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the		"Bit-Forwarding Ingress Router" (BFIR), and leaves the BIER domain at
	BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs).		one or more "Bit-Forwarding Egress Routers" (BFERs). The BFIR router
	The BFIR router adds a BIER header to the packet. The BIER header		adds a BIER header to the packet. Such header contains a bit-string
	contains a bit-string in which each bit represents exactly one BFER		in which each bit represents exactly one BFER to forward the packet
	to forward the packet to. The set of BFERs to which the multicast		to. The set of BFERs to which the multicast packet needs to be
	packet needs to be forwarded is expressed by setting the bits that		forwarded is expressed by the according set of bits switched on in
	correspond to those routers in the BIER header.		BIER packet header.
	This document describes the OSPF protocol extension required for BIER		This document describes the OSPF protocol extension required for BIER
	with MPLS encapsulation.		with MPLS encapsulation.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
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	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on April 21, 2016.		This Internet-Draft will expire on September 22, 2016.
	Copyright Notice		Copyright Notice
	Copyright (c) 2015 IETF Trust and the persons identified as the		Copyright (c) 2016 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
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	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
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	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Flooding of the BIER Information in OSPF . . . . . . . . . . 3		2. Flooding of the BIER Information in OSPF . . . . . . . . . . 3
	2.1. The BIER Sub-TLV . . . . . . . . . . . . . . . . . . . . 3		2.1. The BIER Sub-TLV . . . . . . . . . . . . . . . . . . . . 3
	2.2. The BIER MPLS Encapsulation Sub-TLV . . . . . . . . . . . 4		2.2. The BIER MPLS Encapsulation Sub-TLV . . . . . . . . . . . 4
	2.3. Flooding scope of BIER Information . . . . . . . . . . . 5		2.3. Optional BIER Tree Type Sub-TLV . . . . . . . . . . . . . 5
	3. Security Considerations . . . . . . . . . . . . . . . . . . . 6		2.4. Flooding scope of BIER Information . . . . . . . . . . . 6
	4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6		3. Security Considerations . . . . . . . . . . . . . . . . . . . 7
	5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6		4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
	6. Normative References . . . . . . . . . . . . . . . . . . . . 6		5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7		6. Normative References . . . . . . . . . . . . . . . . . . . . 7
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
	1. Introduction		1. Introduction
	Bit Index Explicit Replication (BIER) is an architecture that		Bit Index Explicit Replication (BIER) is an architecture that
	provides optimal multicast forwarding through a "BIER domain" without		provides optimal multicast forwarding through a "BIER domain" without
	requiring intermediate routers to maintain any multicast related per-		requiring intermediate routers to maintain any multicast related per-
	flow state. Neither does BIER explicitly require a tree-building		flow state. Neither does BIER explicitly require a tree-building
	protocol for its operation. A multicast data packet enters a BIER		protocol for its operation. A multicast data packet enters a BIER
	domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the		domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the
	BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs).		BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs).
	The BFIR router adds a BIER header to the packet. The BIER header		The BFIR router adds a BIER header to the packet. The BIER header
	contains a bit-string in which each bit represents exactly one BFER		contains a bit-string in which each bit represents exactly one BFER
	to forward the packet to. The set of BFERs to which the multicast		to forward the packet to. The set of BFERs to which the multicast
	packet needs to be forwarded is expressed by setting the bits that		packet needs to be forwarded is expressed by setting the bits that
	correspond to those routers in the BIER header.		correspond to those routers in the BIER header.
	BIER architecture requires routers participating in BIER within a		BIER architecture requires routers participating in BIER to exchange
	given BIER domain to exchange some BIER specific information among		BIER related information within a given domain. BIER architecture
	themselves. BIER architecture allows link-state routing protocols to		permits link-state routing protocols to perform distribution of such
	perform the distribution of these information. In this document we		information. This document describes extensions to OSPF necessary to
	describe extensions to OSPF to distribute BIER specific information		carry BIER specific information in the case where BIER uses MPLS
	for the case where BIER uses MPLS encapsulation as described in		encapsulation as described in [I-D.wijnands-mpls-bier-encapsulation].
	[I-D.wijnands-mpls-bier-encapsulation].
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in [RFC2119].		document are to be interpreted as described in [RFC2119].
	2. Flooding of the BIER Information in OSPF		2. Flooding of the BIER Information in OSPF
	All the BIER specific information that a BIER router needs to		All BIER specific information that a BFR needs to advertise to other
	advertise to other BIER routers are associated with the BFR-Prefix, a		BFRs is associated with a BFR-Prefix. BFR prefix is a unique (within
	unique (within a given BIER domain), routable IP address that is		a given BIER domain), routable IP address that is assigned to each
	assign to each BIER router as described in section 2 of		BFR as described in more detail in section 2 of
	[I-D.wijnands-bier-architecture].		[I-D.wijnands-bier-architecture].
	Given that the BIER information is associated with the prefix, the		Given that BIER information must be associated with a BFR prefix, the
	OSPF Extended Prefix Opaque LSA [I-D.ietf-ospf-prefix-link-attr] is		OSPF Extended Prefix Opaque LSA [I-D.ietf-ospf-prefix-link-attr] has
	used to flood BIER related information.		been chosen to flood it.
	2.1. The BIER Sub-TLV		2.1. The BIER Sub-TLV
	A new Sub-TLV of the Extended Prefix TLV (defined in		A new Sub-TLV of the Extended Prefix TLV (defined in
	[I-D.ietf-ospf-prefix-link-attr]) is defined for distributing BIER		[I-D.ietf-ospf-prefix-link-attr]) is defined for distributing BIER
	information. The new Sub-TLV is called BIER Sub-TLV. Multiple BIER		information. The new Sub-TLV is called BIER Sub-TLV. Multiple BIER
	Sub-TLVs may be included in the Extended Prefix TLV.		Sub-TLVs may be included in the Extended Prefix TLV.
	BIER Sub-TLV has the following format:		BIER Sub-TLV has the following format:
	skipping to change at page 4, line 12 ¶		skipping to change at page 4, line 12 ¶
	Length: variable		Length: variable
	Sub-domain-ID: Unique value identifying the BIER sub-domain within		Sub-domain-ID: Unique value identifying the BIER sub-domain within
	the BIER domain, as described in section 1 of		the BIER domain, as described in section 1 of
	[I-D.wijnands-bier-architecture].		[I-D.wijnands-bier-architecture].
	MT-ID: Multi-Topology ID (as defined in [RFC4915]) that identifies		MT-ID: Multi-Topology ID (as defined in [RFC4915]) that identifies
	the topology that is associated with the BIER sub-domain.		the topology that is associated with the BIER sub-domain.
	BFR-id: A 2 octet field encoding the BFR-id, as documented in		BFR-id: A 2 octet field encoding the BFR-id, as documented in
	section 2 [I-D.wijnands-bier-architecture]. If the BFR-id is		section 2 [I-D.wijnands-bier-architecture]. If the BFR is not
	zero, it means, the advertising router is not advertising any		locally configured with a valid BFR-id, the value of this field is
	BIER-id.		set to invalid BFR-id per [I-D.wijnands-bier-architecture].
	Each BFR sub-domain MUST be associate with a single OSPF topology		Each BFR sub-domain MUST be associated with one and only one OSPF
	that is identified by the MT-ID. If the association between BEIR		topology that is identified by the MT-ID. If the association between
	sub-domain and OSPF topology advertised in the BIER sub-TLV is in		BIER sub-domain and OSPF topology advertised in the BIER sub-TLV by
	conflict with the association locally configured on the receiving		other BFRs is in conflict with the association locally configured on
	router, BIER sub-TLV SHOULD be ignored.		the receiving router, whole BIER sub-TLV of the advertising routers
			MUST be ignored.
			If a BFR advertises the same Sub-domain-ID in multiple BIER sub-TLVs,
			the BRF MUST be treated as if it did not advertise a BIER sub-TLV for
			such sub-domain.
			All BFRs MUST detect advertisement of duplicate valid BFR-IDs for a
			given MT-ID and Sub-domain-ID. When such duplication is detected all
			BFRs advertising duplicates MUST be treated as if they did not
			advertise a valid BFR-id.
	2.2. The BIER MPLS Encapsulation Sub-TLV		2.2. The BIER MPLS Encapsulation Sub-TLV
	BIER MPLS Encapsulation Sub-TLV is a sub-TLV of the BIER Sub-TLV.		BIER MPLS Encapsulation Sub-TLV is a sub-TLV of the BIER Sub-TLV.
	BIER MPLS Encapsulation Sub-TLV is used in order to advertise MPLS		BIER MPLS Encapsulation Sub-TLV is used in order to advertise MPLS
	specific information used for BIER. It MAY appear multiple times in		specific information used for BIER. It MAY appear multiple times in
	the BIER Sub-TLV.		the BIER Sub-TLV.
	BIER MPLS Encapsulation Sub-TLV has the following format:		BIER MPLS Encapsulation Sub-TLV has the following format:
	skipping to change at page 4, line 42 ¶		skipping to change at page 5, line 4 ¶
	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 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	|Lbl Range Size | Label Range Base |		|Lbl Range Size | Label Range Base |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| BS Length | Reserved |		| BS Length | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Type: TBD		Type: TBD
	Length: 4 bytes		Length: 4 bytes
	Label Range Size: A 1 octet field encoding the label range size of		Label Range Size: A 1 octet field encoding the label range size of
	the label range. It MUST be greater then 0, otherwise the TLV		the label range. It MUST be greater then 0, otherwise the
	MUST be ignored.		advertising router MUST be treated as if it did not advertise a
			BIER sub-TLV.
	Label Range Base: A 3 octet field, where the 20 rightmost bits		Label Range Base: A 3 octet field, where the 20 rightmost bits
	represent the first label in the label range.		represent the first label in the label range.
	BS Length: A 1 octet field encoding the supported BitString length		BS Length: A 1 octet field encoding the supported BitString length
	associated with this BFR-prefix. The values allowed in this field		associated with this BFR-prefix. The values allowed in this field
	are specified in section 3 of		are specified in section 3 of
	[I-D.wijnands-mpls-bier-encapsulation].		[I-D.wijnands-mpls-bier-encapsulation].
	The "label range" is the set of labels beginning with the label		The "label range" is the set of labels beginning with the label
	skipping to change at page 5, line 24 ¶		skipping to change at page 5, line 33 ¶
	described in [I-D.wijnands-bier-architecture] and		described in [I-D.wijnands-bier-architecture] and
	[I-D.wijnands-mpls-bier-encapsulation].		[I-D.wijnands-mpls-bier-encapsulation].
	The size of the label range is determined by the number of Set		The size of the label range is determined by the number of Set
	Identifiers (SI) (section 2 of [I-D.wijnands-bier-architecture])		Identifiers (SI) (section 2 of [I-D.wijnands-bier-architecture])
	that are used in the network. Each SI maps to a single label in		that are used in the network. Each SI maps to a single label in
	the label range. The first label is for SI=0, the second label is		the label range. The first label is for SI=0, the second label is
	for SI=1, etc.		for SI=1, etc.
	If same BS length is repeated in multiple BIER MPLS Encapsulation		If same BS length is repeated in multiple BIER MPLS Encapsulation
	Sub-TLV inside the same BIER Sub-TLV, the first BIER MPLS		Sub-TLV inside the same BIER Sub-TLV, the advertising router MUST be
	Encapsulation Sub-TLV with such BS length MUST be used and any		treated as if it did not advertise a BIER sub-TLV.
	subsequent BIER MPLS Encapsulation Sub-TLVs with the same BS length
	MUST be ignored.
	Label ranges within all BIER MPLS Encapsulation Sub-TLV inside the		Label ranges within all BIER MPLS Encapsulation Sub-TLV inside the
	same BIER Sub-TLV SHOULD NOT overlap. If the overlap is detected,		same BIER Sub-TLV MUST NOT overlap. If the overlap is detected, the
	overlapping BIER MPLS Encapsulation Sub-TLV SHOULD be ignored.		advertising router MUST be treated as if it did not advertise a BIER
			sub-TLV.
	2.3. Flooding scope of BIER Information		All advertised labels MUST be valid, otherwise the advertising router
			MUST be treated as if it did not advertise a BIER sub-TLV.
			2.3. Optional BIER Tree Type Sub-TLV
			This Sub-TLV carries the information associated with the supported
			BIER tree type for a subdomain. This Sub-TLV is optional and its
			absence has the same semantics as its presence with Tree Type value 0
			(SPF). When Tree Type 0 is used it is recommended that this Sub-TLV
			is omitted in order to reduce the space consumed in the parent TLV.
			This Sub-TLV MAY occur no more than once in a BIER sub-TLV. If
			multiple occurences of this Sub-TLV are present in a single BIER Sub-
			TLV the advertising router MUST be treated as if it did not advertise
			a BIER sub-TLV.
			If the tree type (implied or explicitly advertised) does not match
			the locally configured tree type associated with the matching
			subdomain the advertising router MUST be treated as if it did not
			advertise a BIER sub-TLV.
			0 1 2 3
			0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Type | Length |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Tree Type |
			+-+-+-+-+-+-+-+-+
			Type: value of 1 indicating BIER Tree Type.
			Length: 1 octet.
			Tree Type: 1 octet
			2.4. Flooding scope of BIER Information
	Flooding scope of the OSPF Extended Prefix Opaque LSA		Flooding scope of the OSPF Extended Prefix Opaque LSA
	[I-D.ietf-ospf-prefix-link-attr] that is used for advertising BIER		[I-D.ietf-ospf-prefix-link-attr] that is used for advertising BIER
	Sub TLV is set to area. To allow BIER deployment in a multi-area		Sub TLV is set to area. To allow BIER deployment in a multi-area
	environment, OSPF must propagate BIER information between areas. The		environment, OSPF must propagate BIER information between areas. The
	following procedure is used in order to propagate BIER related		following procedure is used in order to propagate BIER related
	information between areas:		information between areas:
	When an OSPF ABR advertises a Type-3 Summary LSA from an intra-		When an OSPF ABR advertises a Type-3 Summary LSA from an intra-
	area or inter-area prefix to all its connected areas, it will also		area or inter-area prefix to all its connected areas, it will also
	skipping to change at page 6, line 21 ¶		skipping to change at page 7, line 14 ¶
	such BIER MPLS Sub-TLV when advertising BIER MPLS Sub-TLV to		such BIER MPLS Sub-TLV when advertising BIER MPLS Sub-TLV to
	each connected area.		each connected area.
	3. Security Considerations		3. Security Considerations
	Implementations must assure that malformed TLV and Sub-TLV		Implementations must assure that malformed TLV and Sub-TLV
	permutations do not result in errors which cause hard OSPF failures.		permutations do not result in errors which cause hard OSPF failures.
	4. IANA Considerations		4. IANA Considerations
	The document requests two new allocations from the OSPF Extended		The document requests three new allocations from the OSPF Extended
	Prefix sub-TLV registry as defined in		Prefix sub-TLV registry as defined in
	[I-D.ietf-ospf-prefix-link-attr].		[I-D.ietf-ospf-prefix-link-attr].
	BIER Sub-TLV: TBD		BIER Sub-TLV: TBD
	BIER MPLS Encapsulation Sub-TLV: TBD		BIER MPLS Encapsulation Sub-TLV: TBD
			BIER Tree Type Sub-TLV: TBD
	5. Acknowledgments		5. Acknowledgments
	The authors would like to thank Rajiv Asati, Christian Martin, Greg		The authors would like to thank Rajiv Asati, Christian Martin, Greg
	Shepherd and Eric Rosen for their contribution.		Shepherd and Eric Rosen for their contribution.
	6. Normative References		6. Normative References
	[I-D.ietf-ospf-prefix-link-attr]		[I-D.ietf-ospf-prefix-link-attr]
	Psenak, P., Gredler, H., rjs@rob.sh, r., Henderickx, W.,		Psenak, P., Gredler, H., rjs@rob.sh, r., Henderickx, W.,
	Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute		Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
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