< draft-keyupate-ospf-ospfv2-hbit-00.txt		draft-keyupate-ospf-ospfv2-hbit-01.txt >
	OSPF K. Patel		OSPF K. Patel
	Internet-Draft P. Pillay-Esnault		Internet-Draft P. Pillay-Esnault
	Intended status: Standards Track M. Bhardwaj		Intended status: Standards Track M. Bhardwaj
	Expires: November 7, 2015 S. Bayraktar		Expires: November 22, 2015 S. Bayraktar
	Cisco Systems		Cisco Systems
	May 6, 2015		May 21, 2015
	H-bit Support for OSPFv2		H-bit Support for OSPFv2
	draft-keyupate-ospf-ospfv2-hbit-00		draft-keyupate-ospf-ospfv2-hbit-01
	Abstract		Abstract
	OSPFv3 [RFC5340] defines an option field for router-LSAs known as a		OSPFv3 [RFC5340] defines an option field for router-LSAs known as a
	R-bit. If the R-bit is clear, an OSPFv3 router can participate in		R-bit. If the R-bit is clear, an OSPFv3 router can participate in
	OSPF topology distribution without acting as a forwarder to forward		OSPF topology distribution without acting as a forwarder to forward
	the transit traffic. In such cases, an OSPF router would only accept		the transit traffic. In such cases, an OSPF router would only accept
	traffic intended for local delivery. This draft defines R-bit		traffic intended for local delivery. This draft defines R-bit
	functionality for OSPFv2 defined in [RFC2328].		functionality for OSPFv2 defined in [RFC2328].
	skipping to change at page 1, line 37 ¶		skipping to change at page 1, line 37 ¶
	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
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on November 7, 2015.		This Internet-Draft will expire on November 22, 2015.
	Copyright Notice		Copyright Notice
	Copyright (c) 2015 IETF Trust and the persons identified as the		Copyright (c) 2015 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
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://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
	skipping to change at page 2, line 14 ¶		skipping to change at page 2, line 14 ¶
	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 . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2		2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
	3. H-bit Support . . . . . . . . . . . . . . . . . . . . . . . . 3		3. H-bit Support . . . . . . . . . . . . . . . . . . . . . . . . 3
	4. SPF Modifications . . . . . . . . . . . . . . . . . . . . . . 4		4. SPF Modifications . . . . . . . . . . . . . . . . . . . . . . 4
	5. Auto Discovery and Backwards Compatibility . . . . . . . . . 4		5. Auto Discovery and Backwards Compatibility . . . . . . . . . 5
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 5		7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
	8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5		8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
	9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 5		9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 6
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . 5		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
	10.1. Normative References . . . . . . . . . . . . . . . . . . 5		10.1. Normative References . . . . . . . . . . . . . . . . . . 6
	10.2. Informative References . . . . . . . . . . . . . . . . . 6		10.2. Informative References . . . . . . . . . . . . . . . . . 6
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
	1. Introduction		1. Introduction
	OSPFv3 [RFC5340] defines an option field for router-LSAs known as a		OSPFv3 [RFC5340] defines an option field for router-LSAs known as a
	R-bit. If the R-bit is clear, an OSPF router can participate in		R-bit. If the R-bit is clear, an OSPF router can participate in
	OSPFv3 topology distribution without acting as a forwarder to forward		OSPFv3 topology distribution without acting as a forwarder to forward
	the transit traffic. In such cases, an OSPF router would only accept		the transit traffic. In such cases, an OSPF router would only accept
	traffic intended for local delivery.		traffic intended for local delivery.
	This functionality is particularly useful for BGP Route Reflectors		This functionality is particularly useful for BGP Route Reflectors
	skipping to change at page 4, line 16 ¶		skipping to change at page 4, line 16 ¶
	incapable of acting as a forwarder. In this mode, the other OSPFv2		incapable of acting as a forwarder. In this mode, the other OSPFv2
	routers MUST not use the originating OSPFv2 router for the transit		routers MUST not use the originating OSPFv2 router for the transit
	traffic, but they will use the OSPFv2 router for data traffic		traffic, but they will use the OSPFv2 router for data traffic
	destined to that OSPFv2 router. An OSPFv2 router originating a		destined to that OSPFv2 router. An OSPFv2 router originating a
	Router LSA with the H-bit set SHOULD advertise its LINKS with MAX		Router LSA with the H-bit set SHOULD advertise its LINKS with MAX
	Link cost as defined in Section 3 of [RFC6987]. This is to increase		Link cost as defined in Section 3 of [RFC6987]. This is to increase
	the applicability of the H-bit in partial deployments where it is the		the applicability of the H-bit in partial deployments where it is the
	responsibility of the operator to ensure that the H-bit does not		responsibility of the operator to ensure that the H-bit does not
	result in routing loops.		result in routing loops.
			When H-bit is set, only IPv4 prefixes associated with local
			interfaces MAY be advertised in summary LSAs. Non-local IPv4
			prefixes, e.g., those advertised by other routers and installed
			during the SPF computation, MUST NOT be adverised in summary-LSAs.
			Likewise, when H-bit is set, only IPv4 prefixes associated with local
			interfaces MAY be advertised in AS-external LSAs. Non-local IPv4
			prefixes, e.g., those exported from other routing protocols, MUST NOT
			be advertised in AS-external-LSAs. Finally, when H-bit is set, an
			ABR MUST advertise a consistent H-bit setting in its self-originated
			router-LSAs for all attached areas.
	4. SPF Modifications		4. SPF Modifications
	The SPF calculation described in section 16.1 [RFC2328] will be		The SPF calculation described in section 16.1 [RFC2328] will be
	modified to assure that the routers originating router-LSAs with the		modified to assure that the routers originating router-LSAs with the
	H-bit set will not be used for transit traffic. Step 2 is modified		H-bit set will not be used for transit traffic. Step 2 is modified
	as follows:		as follows:
	2) Call the vertex just added to the		2) Call the vertex just added to the
	tree vertex V. Examine the LSA		tree vertex V. Examine the LSA
	associated with vertex V. This is		associated with vertex V. This is
	skipping to change at page 5, line 35 ¶		skipping to change at page 6, line 15 ¶
	Bits TLV.		Bits TLV.
	7. Security Considerations		7. Security Considerations
	This document introduces no new security considerations above and		This document introduces no new security considerations above and
	beyond those already specified in [RFC2328] and [RFC5340].		beyond those already specified in [RFC2328] and [RFC5340].
	8. Acknowledgements		8. Acknowledgements
	The authors would like to acknowledge Acee Lindem, Abhay Roy, David		The authors would like to acknowledge Acee Lindem, Abhay Roy, David
	Ward, and Burjiz Pithawala for their comments.		Ward, Burjiz Pithawala and Michael Barnes for their comments.
	9. Change Log		9. Change Log
	Initial Version: April 23 2015		Initial Version: April 23 2015
	10. References		10. References
	10.1. Normative References		10.1. Normative References
	[I-D.ietf-ospf-rfc4970bis]		[I-D.ietf-ospf-rfc4970bis]
End of changes. 9 change blocks.
	12 lines changed or deleted		23 lines changed or added
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