draft-ietf-babel-source-specific-06.txt		draft-ietf-babel-source-specific-07.txt
	Network Working Group M. Boutier		Network Working Group M. Boutier
	Internet-Draft J. Chroboczek		Internet-Draft J. Chroboczek
	Intended status: Standards Track IRIF, University of Paris-Diderot		Intended status: Standards Track IRIF, University of Paris-Diderot
	Expires: April 13, 2021 October 10, 2020		Expires: May 1, 2021 October 28, 2020
	Source-Specific Routing in Babel		Source-Specific Routing in Babel
	draft-ietf-babel-source-specific-06		draft-ietf-babel-source-specific-07
	Abstract		Abstract
	Source-specific routing (also known as Source-Address Dependent		Source-specific routing (also known as Source-Address Dependent
	Routing, SADR) is an extension to traditional next-hop routing where		Routing, SADR) is an extension to traditional next-hop routing where
	packets are forwarded according to both their destination and their		packets are forwarded according to both their destination and their
	source address. This document describes an extension for source-		source address. This document describes an extension for source-
	specific routing to the Babel routing protocol.		specific routing to the Babel routing protocol.
	Status of This Memo		Status of This Memo
	skipping to change at page 1, line 34 ¶		skipping to change at page 1, line 34 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on April 13, 2021.		This Internet-Draft will expire on May 1, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2020 IETF Trust and the persons identified as the		Copyright (c) 2020 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 5, line 45 ¶		skipping to change at page 5, line 45 ¶
	routes.		routes.
	5. Protocol Operation		5. Protocol Operation
	This extension does not fundamentally change the operation of the		This extension does not fundamentally change the operation of the
	Babel protocol, and we therefore only describe differences between		Babel protocol, and we therefore only describe differences between
	the original protocol and the extended protocol.		the original protocol and the extended protocol.
	In the original protocol, three TLVs carry a destination prefix:		In the original protocol, three TLVs carry a destination prefix:
	Updates, Route Requests and Seqno Requests. This specification		Updates, Route Requests and Seqno Requests. This specification
	extends these messages to optionally carry a Source Prefix sub-TLV,		extends these messages so that they may carry a Source Prefix sub-
	as described in Section 7 below. The sub-TLV is marked as mandatory,		TLV, as described in Section 7 below. The sub-TLV is marked as
	so that an unextended implementation will silently ignore the whole		mandatory, so that an unextended implementation will silently ignore
	enclosing TLV. A node obeying this specification MUST NOT send a TLV		the whole enclosing TLV. A node obeying this specification MUST NOT
	with a zero-length source prefix: instead, it sends a TLV with no		send a TLV with a zero-length source prefix: instead, it sends a TLV
	Source Prefix sub-TLV. Conversely, an extended implementation MUST		with no Source Prefix sub-TLV. Conversely, an extended
	interpret an unextended TLV as carrying a source prefix of zero		implementation MUST interpret an unextended TLV as carrying a source
	length. Taken together, these properties ensure interoperability		prefix of zero length. Taken together, these properties ensure
	between the original and extended protocols (see Section 6 below).		interoperability between the original and extended protocols (see
			Section 6 below).
	5.1. Protocol Messages		5.1. Protocol Messages
	This extension allows three TLVs of the original Babel protocol to		This extension allows three TLVs of the original Babel protocol to
	carry a source prefix: Update TLVs, Route Request TLVs and Seqno		carry a source prefix: Update TLVs, Route Request TLVs and Seqno
	Request TLVs.		Request TLVs.
	In order to advertise a route with a non-zero length source prefix, a		In order to advertise a route with a non-zero length source prefix, a
	node sends a source-specific Update, i.e., an Update with a Source		node sends a source-specific Update, i.e., an Update with a Source
	Prefix sub-TLV. When a node receives a source-specific Update		Prefix sub-TLV. When a node receives a source-specific Update
	skipping to change at page 8, line 29 ¶		skipping to change at page 8, line 29 ¶
	This extension defines a new sub-TLV used to carry a source prefix:		This extension defines a new sub-TLV used to carry a source prefix:
	the Source Prefix sub-TLV. It can be used within an Update, a Route		the Source Prefix sub-TLV. It can be used within an Update, a Route
	Request or a Seqno Request TLV to match a source-specific entry of		Request or a Seqno Request TLV to match a source-specific entry of
	the Route Table, in conjunction with the destination prefix natively		the Route Table, in conjunction with the destination prefix natively
	carried by these TLVs.		carried by these TLVs.
	Since a source-specific routing entry is characterized by a single		Since a source-specific routing entry is characterized by a single
	destination prefix and a single source prefix, a source-specific		destination prefix and a single source prefix, a source-specific
	message contains exactly one Source Prefix sub-TLV. A node MUST NOT		message contains exactly one Source Prefix sub-TLV. A node MUST NOT
	send more that one Source Prefix sub-TLV in a TLV, and a node		send more than one Source Prefix sub-TLV in a TLV, and a node
	receiving more than one Source Prefix sub-TLV in a single TLV SHOULD		receiving more than one Source Prefix sub-TLV in a single TLV MUST
	ignore this TLV. It MAY ignore the whole packet.		ignore this TLV. It MAY ignore the whole packet.
	7.1. Source Prefix sub-TLV		7.1. Source Prefix sub-TLV
	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 = 128 | Length | Source Plen | Source Prefix...		| Type = 128 | Length | Source Plen | Source Prefix...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
	skipping to change at page 10, line 41 ¶		skipping to change at page 10, line 41 ¶
	10. Acknowledgments		10. Acknowledgments
	The authors are grateful to Donald Eastlake and Joel Halpern for		The authors are grateful to Donald Eastlake and Joel Halpern for
	their help with this document.		their help with this document.
	11. References		11. References
	11.1. Normative References		11.1. Normative References
	[BABEL] Chroboczek, J., "The Babel Routing Protocol", Internet		[BABEL] Chroboczek, J. and D. Schinazi, "The Babel Routing
	Draft draft-ietf-babel-rfc6126bis-06, October 2018.		Protocol", Internet Draft draft-ietf-babel-rfc6126bis-20,
			September 2020.
	[BCP84] Baker, F. and P. Savola, "Ingress Filtering for Multihomed		[BCP84] Baker, F. and P. Savola, "Ingress Filtering for Multihomed
	Networks", BCP 84, RFC 3704, March 2004.		Networks", BCP 84, RFC 3704, March 2004.
	[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.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
End of changes. 6 change blocks.
	16 lines changed or deleted		18 lines changed or added
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