draft-ietf-grow-mrt-add-paths-03.txt		rfc8050.txt
	Global Routing Operations C. Petrie		Internet Engineering Task Force (IETF) C. Petrie
	Internet-Draft RIPE NCC		Request for Comments: 8050 RIPE NCC
	Intended status: Standards Track T. King		Category: Standards Track T. King
	Expires: July 18, 2017 DE-CIX		ISSN: 2070-1721 DE-CIX
	January 14, 2017		May 2017
	Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format		Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format
	with BGP Additional Paths Extensions		with BGP Additional Path Extensions
	draft-ietf-grow-mrt-add-paths-03
	Abstract		Abstract
	This document updates the Multi-threaded Routing Toolkit (MRT) export		This document extends the Multi-threaded Routing Toolkit (MRT) export
	format for Border Gateway Protocol (BGP) routing information by		format for Border Gateway Protocol (BGP) routing information by
	extending it to support the Advertisement of Multiple Paths in BGP		supporting the advertisement of multiple paths in BGP extensions.
	extensions.
	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
	Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		This document is a product of the Internet Engineering Task Force
	and may be updated, replaced, or obsoleted by other documents at any		(IETF). It represents the consensus of the IETF community. It has
	time. It is inappropriate to use Internet-Drafts as reference		received public review and has been approved for publication by the
	material or to cite them other than as "work in progress."		Internet Engineering Steering Group (IESG). Further information on
			Internet Standards is available in Section 2 of RFC 7841.
	This Internet-Draft will expire on July 18, 2017.		Information about the current status of this document, any errata,
			and how to provide feedback on it may be obtained at
			http://www.rfc-editor.org/info/rfc8050.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 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 13 ¶		skipping to change at page 2, line 11 ¶
	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. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 2		2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 2
	3. MRT Subtypes for Types BGP4MP/BGP4MP_ET . . . . . . . . . . . 3		3. MRT Subtypes for Types BGP4MP/BGP4MP_ET . . . . . . . . . . . 3
	4. MRT Subtypes for Type TABLE_DUMP_V2 . . . . . . . . . . . . . 3		4. MRT Subtypes for Type TABLE_DUMP_V2 . . . . . . . . . . . . . 3
	4.1. AFI/SAFI specific RIB Subtypes . . . . . . . . . . . . . 3		4.1. AFI/SAFI-Specific RIB Subtypes . . . . . . . . . . . . . 4
	4.2. RIB_GENERIC_ADDPATH Subtype . . . . . . . . . . . . . . . 4		4.2. RIB_GENERIC_ADDPATH Subtype . . . . . . . . . . . . . . . 4
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
	5.1. BGP4MP/BGP4MP_ET Subtype codes: . . . . . . . . . . . . . 4		5.1. BGP4MP/BGP4MP_ET Subtype Codes . . . . . . . . . . . . . 5
	5.2. TABLE_DUMP_V2 Subtype codes: . . . . . . . . . . . . . . 5		5.2. TABLE_DUMP_V2 Subtype Codes . . . . . . . . . . . . . . . 5
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 5		6. Security Considerations . . . . . . . . . . . . . . . . . . . 5
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5		7. Normative References . . . . . . . . . . . . . . . . . . . . 6
	7.1. Normative References . . . . . . . . . . . . . . . . . . 5
	7.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 6
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
	1. Introduction		1. Introduction
	The MRT record format [RFC6396] was developed to provide researchers		The MRT record format [RFC6396] was developed to provide researchers
	and engineers a means to encapsulate, export, and archive routing		and engineers a means to encapsulate, export, and archive routing
	protocol transactions and routing information base snapshots.		protocol transactions and RIB snapshots.
	The Advertisement of Multiple Paths in BGP [RFC7911] defines a BGP		The Advertisement of Multiple Paths in BGP [RFC7911] defines a BGP
	extension to allow the advertisement of multiple paths for the same		extension to allow the advertisement of multiple paths for the same
	address prefix without the new paths implicitly replacing any		address prefix without the new paths implicitly replacing any
	previous ones.		previous ones.
	This document contains an optional extension to the MRT format		This document contains an optional extension to the MRT format
	[RFC6396] and introduces additional definitions of MRT subtype fields		[RFC6396] and introduces additional definitions of MRT subtype fields
	to permit representation of multiple path advertisements [RFC7911].		to permit representation of multiple path advertisements [RFC7911].
	2. Rationale		2. Rationale
	MRT parsers are usually stateless. In order to parse BGP messages		MRT parsers are usually stateless. In order to parse BGP messages
	which contain data structures that depend on the capabilities		that contain data structures that depend on the capabilities
	negotiated during the BGP session setup, the so-called MRT subtypes		negotiated during the BGP session setup, the MRT subtypes are
	are utilized. The Advertisement of Multiple Path [RFC7911] extension		utilized. The Advertisement of Multiple Paths [RFC7911] extension
	for BGP alters the encoding of the BGP NLRI format for withdraws and		for BGP alters the encoding of the BGP Network Layer Reachability
	announcements. Therefore new BGP4MP/BGP4MP_ET subtypes as defined in		Information (NLRI) format for withdraws and announcements.
	[RFC6396] are required to signal to a MRT parser how to parse the		Therefore, new BGP4MP/BGP4MP_ET subtypes as defined in [RFC6396] are
	NLRI.		required to signal to an MRT parser how to parse the NLRI.
	In section 4.3 [RFC6396] of the MRT specification RIB subtypes are		In Section 4.3 of the MRT specification [RFC6396], RIB subtypes are
	specified. Prefix length and prefix fields are encoded in the same		specified. Prefix length and prefix fields are encoded in the same
	manner as the BGP NLRI encoding. In order to support path identifier		manner as the BGP NLRI encoding. In order to support Path Identifier
	information as defined in [RFC7911] new subtypes need to be added.		information as defined in [RFC7911], new subtypes need to be added.
	The following two sections define the required subtypes.		The following two sections define the required subtypes.
	3. MRT Subtypes for Types BGP4MP/BGP4MP_ET		3. MRT Subtypes for Types BGP4MP/BGP4MP_ET
	This document defines the following new Subtypes:		This document defines the following new subtypes:
	o BGP4MP_MESSAGE_ADDPATH		o BGP4MP_MESSAGE_ADDPATH
	o BGP4MP_MESSAGE_AS4_ADDPATH		o BGP4MP_MESSAGE_AS4_ADDPATH
	o BGP4MP_MESSAGE_LOCAL_ADDPATH		o BGP4MP_MESSAGE_LOCAL_ADDPATH
	o BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH		o BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH
	The fields of these message types are identical to the equivalent		The fields of these message types are identical to the equivalent
	non-additional-path versions specified in section 4.4 [RFC6396].		non-additional-path versions specified in Section 4.4 of [RFC6396].
	These enhancements continues to encapsulate the entire BGP message in		These enhancements continue to encapsulate the entire BGP message in
	the BGP message field.		the BGP message field.
	4. MRT Subtypes for Type TABLE_DUMP_V2		4. MRT Subtypes for Type TABLE_DUMP_V2
	This document defines the following new Subtypes:		This document defines the following new subtypes:
	o RIB_IPV4_UNICAST_ADDPATH		o RIB_IPV4_UNICAST_ADDPATH
	o RIB_IPV4_MULTICAST_ADDPATH		o RIB_IPV4_MULTICAST_ADDPATH
	o RIB_IPV6_UNICAST_ADDPATH		o RIB_IPV6_UNICAST_ADDPATH
	o RIB_IPV6_MULTICAST_ADDPATH		o RIB_IPV6_MULTICAST_ADDPATH
	o RIB_GENERIC_ADDPATH		o RIB_GENERIC_ADDPATH
	The fields of these message types are identical to the equivalent		The fields of these message types are identical to the equivalent
	non-additional-path versions specified in section 4.3 [RFC6396].		non-additional-path versions specified in Section 4.3 of [RFC6396].
	However, for the specific case of the 4 AFI/SAFI specific RIB		However, for the case of the 4 AFI/SAFI-specific RIB subtypes, the
	subtypes, the existing RIB Entries field is re-defined as detailed in		existing RIB Entries field is redefined as detailed in the sections
	the sections below.		below.
	4.1. AFI/SAFI specific RIB Subtypes		4.1. AFI/SAFI-Specific RIB Subtypes
	In order to preserve the record compaction achieved by using the most		In order to preserve the record compaction achieved by using the most
	common subtypes, and allowing multiple RIB Entries to be stored in a		common subtypes and allow multiple RIB Entries to be stored in a
	single TABLE_DUMP_V2 record, the existing RIB Entries field is		single TABLE_DUMP_V2 record, the existing RIB Entries field is
	redefined for use within the new AFI/SAFI specific RIB Subtypes		redefined for use within the new AFI/SAFI-specific RIB subtypes
	defined by this document as follows:		defined by this document 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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Peer Index |		| Peer Index |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Originated Time |		| Originated Time |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Path Identifier |		| Path Identifier |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Attribute Length |		| Attribute Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| BGP Attributes... (variable)		| BGP Attributes... (variable)
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 1: RIB Entries for AFI/SAFI-specific RIB Subtypes with		Figure 1: RIB Entries for AFI/SAFI-Specific RIB Subtypes with
	additional-paths support		Support for Additional Paths
	This adds a field to the RIB Entries record, to store the path		This adds a field to the RIB Entries record to store the Path
	identifier, when used with the RIB_IPV4_UNICAST_ADDPATH,		Identifier when used with the RIB_IPV4_UNICAST_ADDPATH,
	RIB_IPV4_MULTICAST_ADDPATH, RIB_IPV6_UNICAST_ADDPATH and		RIB_IPV4_MULTICAST_ADDPATH, RIB_IPV6_UNICAST_ADDPATH, and
	RIB_IPV6_MULTICAST_ADDPATH subtypes.		RIB_IPV6_MULTICAST_ADDPATH subtypes.
	4.2. RIB_GENERIC_ADDPATH Subtype		4.2. RIB_GENERIC_ADDPATH Subtype
	The fields of this subtype are identical to the equivalent non-		The fields of this subtype are identical to the equivalent non-
	additional-path versions specified in section 4.3.3 [RFC6396]. These		additional-path versions specified in Section 4.3.3 of [RFC6396].
	fields continue to encapsulate the raw and additional-path enabled		These fields continue to encapsulate the raw and additional-path-
	AFI/SAFI/NLRI in the record, and the raw attributes in the RIB		enabled AFI/SAFI/NLRI in the record, and the raw attributes in the
	Entries.		RIB Entries.
	For clarity, the RIB Entries in this subtype are not redefined.		For clarity, the RIB Entries in this subtype are not redefined.
	5. IANA Considerations		5. IANA Considerations
	This document requests that IANA assign the following subtype codes		IANA has assigned the subtype codes defined below in the "Multi-
	to the MRT name space [1]:		threaded Routing Toolkit (MRT)" registry
			<https://www.iana.org/assignments/mrt>.
	5.1. BGP4MP/BGP4MP_ET Subtype codes:		5.1. BGP4MP/BGP4MP_ET Subtype Codes
	BGP4MP_MESSAGE_ADDPATH = 8 (Section 3)		The following have been registered in the "BGP4MP Subtype Codes" and
			"BGP4MP_ET Subtype Codes" registries:
	BGP4MP_MESSAGE_AS4_ADDPATH = 9 (Section 3)		8 BGP4MP_MESSAGE_ADDPATH (RFC 8050)
	BGP4MP_MESSAGE_LOCAL_ADDPATH = 10 (Section 3)		9 BGP4MP_MESSAGE_AS4_ADDPATH (RFC 8050)
	BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH = 11 (Section 3)
	The values provided above are suggested as they are used in		10 BGP4MP_MESSAGE_LOCAL_ADDPATH (RFC 8050)
	implementations.
	5.2. TABLE_DUMP_V2 Subtype codes:		11 BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH (RFC 8050)
	RIB_IPV4_UNICAST_ADDPATH = 8 (Section 4.1)		5.2. TABLE_DUMP_V2 Subtype Codes
	RIB_IPV4_MULTICAST_ADDPATH = 9 (Section 4.1)		The following have been registered in the "TABLE_DUMP_V2 Subtype
			Codes" registry:
	RIB_IPV6_UNICAST_ADDPATH = 10 (Section 4.1)		8 RIB_IPV4_UNICAST_ADDPATH (RFC 8050)
	RIB_IPV6_MULTICAST_ADDPATH = 11 (Section 4.1)		9 RIB_IPV4_MULTICAST_ADDPATH (RFC 8050)
	RIB_GENERIC_ADDPATH = 12 (Section 4.2)		10 RIB_IPV6_UNICAST_ADDPATH (RFC 8050)
	The values provided above are suggested as they are used in		11 RIB_IPV6_MULTICAST_ADDPATH (RFC 8050)
	implementations.
			12 RIB_GENERIC_ADDPATH (RFC 8050)
	6. Security Considerations		6. Security Considerations
	It is not believed that this document adds any additional security		It is not believed that this document adds any additional security
	considerations.		considerations. However, the security considerations of [RFC6396]
			are equally applicable to this document, because this document
	However, the security considerations of [RFC6396] are equally		permits the export of more detailed routing data.
	applicable to this document, and this document permits the export of
	more detailed routing data.
	An organization that uses the MRT format to store their BGP routing		An organization that uses the MRT format to store their BGP routing
	information should be aware that supporting these extensions permits		information should be aware that supporting these extensions permits
	more detailed network path information to be stored, and should		more detailed network path information to be stored and should
	consider the implications of this within their environment.		consider the implications of this within their environment.
	An organization that peers with public BGP collectors, and enables		An organization that peers with public BGP collectors and enables the
	the additional-paths capability on a peering session, should be aware		capability for additional paths on a peering session should be aware
	that it is exporting not only its best paths, but potentially other		that it is exporting not only its best paths, but potentially other
	paths within its networks. The BGP peer should consider any and all		paths within its networks. The BGP peer should consider any and all
	implications of exposing this additional data.		implications of exposing this additional data.
	7. References		7. Normative References
	7.1. Normative References
	[RFC6396] Blunk, L., Karir, M., and C. Labovitz, "Multi-Threaded		[RFC6396] Blunk, L., Karir, M., and C. Labovitz, "Multi-Threaded
	Routing Toolkit (MRT) Routing Information Export Format",		Routing Toolkit (MRT) Routing Information Export Format",
	RFC 6396, DOI 10.17487/RFC6396, October 2011,		RFC 6396, DOI 10.17487/RFC6396, October 2011,
	<http://www.rfc-editor.org/info/rfc6396>.		<http://www.rfc-editor.org/info/rfc6396>.
	[RFC7911] Walton, D., Retana, A., Chen, E., and J. Scudder,		[RFC7911] Walton, D., Retana, A., Chen, E., and J. Scudder,
	"Advertisement of Multiple Paths in BGP", RFC 7911,		"Advertisement of Multiple Paths in BGP", RFC 7911,
	DOI 10.17487/RFC7911, July 2016,		DOI 10.17487/RFC7911, July 2016,
	<http://www.rfc-editor.org/info/rfc7911>.		<http://www.rfc-editor.org/info/rfc7911>.
	7.2. URIs
	[1] https://www.iana.org/assignments/mrt/mrt.xhtml
	Authors' Addresses		Authors' Addresses
	Colin Petrie		Colin Petrie
	RIPE NCC		RIPE NCC
	Stationsplein 11		Stationsplein 11
	Amsterdam 1012 AB		Amsterdam 1012 AB
	NL		The Netherlands
	Email: cpetrie@ripe.net		Email: cpetrie@ripe.net
	Thomas King		Thomas King
	DE-CIX Management GmbH		DE-CIX Management GmbH
	Lichtstrasse 43i		Lichtstrasse 43i
	Cologne 50825		Cologne 50825
	Germany		Germany
	Email: thomas.king@de-cix.net		Email: thomas.king@de-cix.net
End of changes. 43 change blocks.
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