draft-ietf-grow-bmp-local-rib-09.txt		draft-ietf-grow-bmp-local-rib-10.txt
	Global Routing Operations T. Evens		Global Routing Operations T. Evens
	Internet-Draft S. Bayraktar		Internet-Draft S. Bayraktar
	Updates: 7854 (if approved) M. Bhardwaj		Updates: 7854 (if approved) M. Bhardwaj
	Intended status: Standards Track Cisco Systems		Intended status: Standards Track Cisco Systems
	Expires: 18 July 2021 P. Lucente		Expires: 9 September 2021 P. Lucente
	NTT Communications		NTT Communications
	14 January 2021		8 March 2021
	Support for Local RIB in BGP Monitoring Protocol (BMP)		Support for Local RIB in BGP Monitoring Protocol (BMP)
	draft-ietf-grow-bmp-local-rib-09		draft-ietf-grow-bmp-local-rib-10
	Abstract		Abstract
	The BGP Monitoring Protocol (BMP) defines access to various Routing		The BGP Monitoring Protocol (BMP) defines access to various Routing
	Information Bases (RIBs). This document updates BMP (RFC 7854) by		Information Bases (RIBs). This document updates BMP (RFC 7854) by
	adding access to the Local Routing Information Base (Loc-RIB), as		adding access to the Local Routing Information Base (Loc-RIB), as
	defined in RFC 4271. The Loc-RIB contains the routes that have been		defined in RFC 4271. The Loc-RIB contains the routes that have been
	selected by the local BGP speaker's Decision Process.		selected by the local BGP speaker's Decision Process.
	Status of This Memo		Status of This Memo
	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 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 18 July 2021.		This Internet-Draft will expire on 9 September 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2021 IETF Trust and the persons identified as the		Copyright (c) 2021 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 (https://trustee.ietf.org/		Provisions Relating to IETF Documents (https://trustee.ietf.org/
	license-info) in effect on the date of publication of this document.		license-info) in effect on the date of publication of this document.
	Please review these documents carefully, as they describe your rights		Please review these documents carefully, as they describe your rights
	skipping to change at page 3, line 41 ¶		skipping to change at page 3, line 41 ¶
	| V V |		| V V |
	| +-----------------------------------------+ |		| +-----------------------------------------+ |
	| | Loc-RIB | |		| | Loc-RIB | |
	| +-----------------------------------------+ |		| +-----------------------------------------+ |
	| |		| |
	| ROUTER/BGP Instance |		| ROUTER/BGP Instance |
	\----------------------------------------------------/		\----------------------------------------------------/
	Figure 1: BGP peering Adj-RIBs-In into Loc-RIB		Figure 1: BGP peering Adj-RIBs-In into Loc-RIB
	As shown in Figure 2, Locally originated section 9.4 of [RFC4271]		Figure 2 (Locally Originated into Loc-RIB) illustrates how
	follows a similar flow where the redistributed or otherwise		redistributed or otherwise originated routes get installed into the
	originated routes get installed into the Loc-RIB based on the		Loc-RIB based on the decision process selection in RFC 4271
	decision process selection.		[RFC4271].
	/--------------------------------------------------------\		/--------------------------------------------------------\
	| |		| |
	| +----------+ +----------+ +----------+ +----------+ |		| +----------+ +----------+ +----------+ +----------+ |
	| | IS-IS | | OSPF | | Static | | BGP | |		| | IS-IS | | OSPF | | Static | | BGP | |
	| +----------+ +----------+ +----------+ +----------+ |		| +----------+ +----------+ +----------+ +----------+ |
	| | | | | |		| | | | | |
	| | | |		| | | |
	| | Redistributed or originated into BGP | |		| | Redistributed or originated into BGP | |
	| | | |		| | | |
	skipping to change at page 4, line 41 ¶		skipping to change at page 4, line 41 ¶
	flow records to Loc-RIB entries, only need to collect and monitor		flow records to Loc-RIB entries, only need to collect and monitor
	the routes that are actually selected and used.		the routes that are actually selected and used.
	Requiring the applications to collect all Adj-RIB-In Post-Policy		Requiring the applications to collect all Adj-RIB-In Post-Policy
	data forces the applications to receive a potentially large		data forces the applications to receive a potentially large
	unwanted data set and to perform the BGP decision process		unwanted data set and to perform the BGP decision process
	selection, which includes having access to the IGP next-hop		selection, which includes having access to the IGP next-hop
	metrics. While it is possible to obtain the IGP topology		metrics. While it is possible to obtain the IGP topology
	information using BGP-LS, it requires the application to implement		information using BGP-LS, it requires the application to implement
	SPF and possibly CSPF based on additional policies. This is		SPF and possibly CSPF based on additional policies. This is
	overly complex for such a simple application that only needed to		overly complex for such a simple application that only needs to
	have access to the Loc-RIB.		have access to the Loc-RIB.
	* It is common to see frequent changes over many BGP peers, but		* It is common to see frequent changes over many BGP peers, but
	those changes do not always result in the router's Loc-RIB		those changes do not always result in the router's Loc-RIB
	changing. The change in the Loc-RIB can have a direct impact on		changing. The change in the Loc-RIB can have a direct impact on
	the forwarding state. It can greatly reduce time to troubleshoot		the forwarding state. It can greatly reduce time to troubleshoot
	and resolve issues if operators had the history of Loc-RIB		and resolve issues if operators have the history of Loc-RIB
	changes. For example, a performance issue might have been seen		changes. For example, a performance issue might have been seen
	for only a duration of 5 minutes. Post troubleshooting this issue		for only a duration of 5 minutes. Post troubleshooting this issue
	without Loc-RIB history hides any decision based routing changes		without Loc-RIB history hides any decision based routing changes
	that might have happened during those five minutes.		that might have happened during those five minutes.
	* Operators may wish to validate the impact of policies applied to		* Operators may wish to validate the impact of policies applied to
	Adj-RIB-In by analyzing the final decision made by the router when		Adj-RIB-In by analyzing the final decision made by the router when
	installing into the Loc-RIB. For example, in order to validate if		installing into the Loc-RIB. For example, in order to validate if
	multi-path prefixes are installed as expected for all advertising		multi-path prefixes are installed as expected for all advertising
	peers, the Adj-RIB-In Post-Policy and Loc-RIB needs to be		peers, the Adj-RIB-In Post-Policy and Loc-RIB needs to be
	skipping to change at page 6, line 46 ¶		skipping to change at page 6, line 46 ¶
	Figure 3: Alternative method to monitor Loc-RIB		Figure 3: Alternative method to monitor Loc-RIB
	The setup needed to monitor the Loc-RIB of a router requires another		The setup needed to monitor the Loc-RIB of a router requires another
	router with a peering session to the target router that is to be		router with a peering session to the target router that is to be
	monitored. As shown in Figure 3, the target router Loc-RIB is		monitored. As shown in Figure 3, the target router Loc-RIB is
	advertised via Adj-RIB-Out to the BMP router over a standard BGP		advertised via Adj-RIB-Out to the BMP router over a standard BGP
	peering session. The BMP router then forwards Adj-RIB-In Pre-Policy		peering session. The BMP router then forwards Adj-RIB-In Pre-Policy
	to the BMP receiver.		to the BMP receiver.
	The current method introduces the need for additional resources:		BMP lacking access to Loc-RIB introduces the need for additional
			resources:
	* Requires at least two routers when only one router was to be		* Requires at least two routers when only one router was to be
	monitored.		monitored.
	* Requires additional BGP peering to collect the received updates		* Requires additional BGP peering to collect the received updates
	when peering may have not even been required in the first place.		when peering may have not even been required in the first place.
	For example, VRFs with no peers, redistributed BGP-LS with no		For example, VRFs with no peers, redistributed BGP-LS with no
	peers, segment routing egress peer engineering where no peers have		peers, segment routing egress peer engineering where no peers have
	link-state address family enabled.		link-state address family enabled.
	Complexities introduced with current method in order to derive (e.g.		Complexities introduced by the lack of access to Loc-RIB in order to
	correlate) peer to router Loc-RIB:		derive (e.g. correlate) peer to router Loc-RIB:
	* Adj-RIB-Out received as Adj-RIB-In from another router may have a		* Adj-RIB-Out received as Adj-RIB-In from another router may have a
	policy applied that filters, generates aggregates, suppresses more		policy applied that filters, generates aggregates, suppresses more
	specifics, manipulates attributes, or filters routes. Not only		specifics, manipulates attributes, or filters routes. Not only
	does this invalidate the Loc-RIB view, it adds complexity when		does this invalidate the Loc-RIB view, it adds complexity when
	multiple BMP routers may have peering sessions to the same router.		multiple BMP routers may have peering sessions to the same router.
	The BMP receiver user is left with the error prone task of		The BMP receiver user is left with the error prone task of
	identifying which peering session is the best representative of		identifying which peering session is the best representative of
	the Loc-RIB.		the Loc-RIB.
	skipping to change at page 8, line 4 ¶		skipping to change at page 8, line 4 ¶
	2. Terminology		2. Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in BCP
	14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they		14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they
	appear in all capitals, as shown here.		appear in all capitals, as shown here.
	3. Definitions		3. Definitions
	* BGP Instance: it refers to an instance of an instance of BGP-4		* BGP Instance: refers to an instance of an instance of BGP-4
	[RFC4271] and considerations in section 8.1 of [RFC7854] do apply		[RFC4271] and considerations in section 8.1 of [RFC7854] do apply
	to it.		to it.
	* Adj-RIB-In: As defined in [RFC4271], "The Adj-RIBs-In contains		* Adj-RIB-In: As defined in [RFC4271], "The Adj-RIBs-In contains
	unprocessed routing information that has been advertised to the		unprocessed routing information that has been advertised to the
	local BGP speaker by its peers." This is also referred to as the		local BGP speaker by its peers." This is also referred to as the
	pre-policy Adj-RIB-In in this document.		pre-policy Adj-RIB-In in this document.
	* Adj-RIB-Out: As defined in [RFC4271], "The Adj-RIBs-Out contains		* Adj-RIB-Out: As defined in [RFC4271], "The Adj-RIBs-Out contains
	the routes for advertisement to specific peers by means of the		the routes for advertisement to specific peers by means of the
	skipping to change at page 8, line 47 ¶		skipping to change at page 8, line 47 ¶
	Section 4.2 of [RFC7854] defines a Local Instance Peer type, which is		Section 4.2 of [RFC7854] defines a Local Instance Peer type, which is
	for the case of non-RD peers that have an instance identifier.		for the case of non-RD peers that have an instance identifier.
	This document defines the following new peer type:		This document defines the following new peer type:
	* Peer Type = 3: Loc-RIB Instance Peer		* Peer Type = 3: Loc-RIB Instance Peer
	4.2. Peer Flags		4.2. Peer Flags
	In section 4.2 of [RFC7854], the "locally sourced routes" comment		In section 4.2 of [RFC7854], the "locally sourced routes" comment
	under the L flag description is removed. Locally sourced routes MUST		under the L flag description is removed. If locally sourced routes
	be conveyed using the Loc-RIB instance peer type.		are communicated using BMP, they MUST be conveyed using the Loc-RIB
			instance peer type.
	The per-peer header flags for Loc-RIB Instance Peer type are defined		The per-peer header flags for Loc-RIB Instance Peer type are defined
	as follows:		as follows:
	0 1 2 3 4 5 6 7		0 1 2 3 4 5 6 7
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	|F| Reserved |		|F| Reserved |
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	* The F flag indicates that the Loc-RIB is filtered. This MUST be		* The F flag indicates that the Loc-RIB is filtered. This MUST be
	set when only a subset of Loc-RIB routes is sent to the BMP		set when only a subset of Loc-RIB routes is sent to the BMP
	collector.		collector.
	The remaining bits are reserved for future use. They MUST be		The remaining bits are reserved for future use. They MUST be
	transmitted as 0 and their values MUST be ignored on receipt.		transmitted as 0 and their values MUST be ignored on receipt.
	5. Loc-RIB Monitoring		5. Loc-RIB Monitoring
	The Loc-RIB contains all routes selected by the BGP protocol Decision		The Loc-RIB contains all routes selected by the BGP protocol Decision
	Process section 9.1 of [RFC4271]. These routes include those learned		Process as described in section 9.1 of [RFC4271]. These routes
	from BGP peers via its Adj-RIBs-In post-policy, as well as routes		include those learned from BGP peers via its Adj-RIBs-In post-policy,
	learned by other means section 9.4 of [RFC4271]. Examples of these		as well as routes learned by other means as per section 9.4 of
	include redistribution of routes from other protocols into BGP or		[RFC4271]. Examples of these include redistribution of routes from
	otherwise locally originated (ie. aggregate routes).		other protocols into BGP or otherwise locally originated (ie.
			aggregate routes).
	As mentioned in Section 4.2 a subset of Loc-RIB routes MAY be sent to		As mentioned in Section 4.2 a subset of Loc-RIB routes MAY be sent to
	a BMP collector by setting the F flag.		a BMP collector by setting the F flag.
	5.1. Per-Peer Header		5.1. Per-Peer Header
	All peer messages that include a per-peer header MUST use the		All peer messages that include a per-peer header section 4.2 of
	following values:		[RFC7854] MUST use the following values:
	* Peer Type: Set to 3 to indicate Loc-RIB Instance Peer.		* Peer Type: Set to 3 to indicate Loc-RIB Instance Peer.
	* Peer Distinguisher: Zero filled if the Loc-RIB represents the		* Peer Distinguisher: Zero filled if the Loc-RIB represents the
	global instance. Otherwise set to the route distinguisher or		global instance. Otherwise set to the route distinguisher or
	unique locally defined value of the particular instance the Loc-		unique locally defined value of the particular instance the Loc-
	RIB belongs to.		RIB belongs to.
	* Peer Address: Zero-filled. Remote peer address is not applicable.		* Peer Address: Zero-filled. Remote peer address is not applicable.
	The V flag is not applicable with Loc-RIB Instance peer type		The V flag is not applicable with Loc-RIB Instance peer type
	considering addresses are zero-filed.		considering addresses are zero-filed.
	* Peer AS: Set to the BGP instance global or default ASN value.		* Peer AS: Set to the primary router BGP ASN.
	* Peer BGP ID: Set to the BGP instance global or RD (e.g. VRF)		* Peer BGP ID: Set to the BGP instance global or RD (e.g. VRF)
	specific router-id section 1.1 of [RFC7854].		specific router-id section 1.1 of [RFC7854].
	* Timestamp: The time when the encapsulated routes were installed in		* Timestamp: The time when the encapsulated routes were installed in
	The Loc-RIB, expressed in seconds and microseconds since midnight		The Loc-RIB, expressed in seconds and microseconds since midnight
	(zero hour), January 1, 1970 (UTC). If zero, the time is		(zero hour), January 1, 1970 (UTC). If zero, the time is
	unavailable. Precision of the timestamp is implementation-		unavailable. Precision of the timestamp is implementation-
	dependent.		dependent.
	skipping to change at page 10, line 23 ¶		skipping to change at page 10, line 23 ¶
	Peer UP notifications follow section 4.10 of [RFC7854] with the		Peer UP notifications follow section 4.10 of [RFC7854] with the
	following clarifications:		following clarifications:
	* Local Address: Zero-filled, local address is not applicable.		* Local Address: Zero-filled, local address is not applicable.
	* Local Port: Set to 0, local port is not applicable.		* Local Port: Set to 0, local port is not applicable.
	* Remote Port: Set to 0, remote port is not applicable.		* Remote Port: Set to 0, remote port is not applicable.
	* Sent OPEN Message: This is a fabricated BGP OPEN message.		* Sent OPEN Message: This is a fabricated BGP OPEN message.
	Capabilities MUST include 4-octet ASN and all necessary		Capabilities MUST include the 4-octet ASN and all necessary
	capabilities to represent the Loc-RIB route monitoring messages.		capabilities to represent the Loc-RIB route monitoring messages.
	Only include capabilities if they will be used for Loc-RIB		Only include capabilities if they will be used for Loc-RIB
	monitoring messages. For example, if add-paths is enabled for		monitoring messages. For example, if add-paths is enabled for
	IPv6 and Loc-RIB contains additional paths, the add-paths		IPv6 and Loc-RIB contains additional paths, the add-paths
	capability should be included for IPv6. In the case of add-paths,		capability should be included for IPv6. In the case of add-paths,
	the capability intent of advertise, receive or both can be ignored		the capability intent of advertise, receive or both can be ignored
	since the presence of the capability indicates enough that add-		since the presence of the capability indicates enough that add-
	paths will be used for IPv6.		paths will be used for IPv6.
	* Received OPEN Message: Repeat of the same Sent Open Message. The		* Received OPEN Message: Repeat of the same Sent Open Message. The
	skipping to change at page 11, line 44 ¶		skipping to change at page 11, line 44 ¶
	Loc-RIB route monitor messages MUST use 4-byte ASN encoding as		Loc-RIB route monitor messages MUST use 4-byte ASN encoding as
	indicated in PEER UP sent OPEN message (Section 5.2) capability.		indicated in PEER UP sent OPEN message (Section 5.2) capability.
	5.4.2. Granularity		5.4.2. Granularity
	State compression and throttling SHOULD be used by a BMP sender to		State compression and throttling SHOULD be used by a BMP sender to
	reduce the amount of route monitoring messages that are transmitted		reduce the amount of route monitoring messages that are transmitted
	to BMP receivers. With state compression, only the final resultant		to BMP receivers. With state compression, only the final resultant
	updates are sent.		updates are sent.
	For example, prefix 10.0.0.0/8 is updated in the Loc-RIB 5 times		For example, prefix 192.0.2.0/24 is updated in the Loc-RIB 5 times
	within 1 second. State compression of BMP route monitor messages		within 1 second. State compression of BMP route monitor messages
	results in only the final change being transmitted. The other 4		results in only the final change being transmitted. The other 4
	changes are suppressed because they fall within the compression		changes are suppressed because they fall within the compression
	interval. If no compression was being used, all 5 updates would have		interval. If no compression was being used, all 5 updates would have
	been transmitted.		been transmitted.
	A BMP receiver should expect that Loc-RIB route monitoring		A BMP receiver should expect that Loc-RIB route monitoring
	granularity can be different by BMP sender implementation.		granularity can be different by BMP sender implementation.
	5.5. Route Mirroring		5.5. Route Mirroring
End of changes. 16 change blocks.
	26 lines changed or deleted		29 lines changed or added
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