< draft-ietf-bess-evpn-pref-df-00.txt		draft-ietf-bess-evpn-pref-df-01.txt >
	BESS Workgroup J. Rabadan, Ed.		BESS Workgroup J. Rabadan, Ed.
	Internet Draft S. Sathappan		Internet Draft S. Sathappan
	Intended status: Standards Track Nokia		Intended status: Standards Track Nokia
	S. Boutros T. Przygienda		S. Boutros T. Przygienda
	VMware W. Lin		Individual W. Lin
	J. Drake		J. Drake
	Juniper Networks		Juniper Networks
	A. Sajassi		A. Sajassi
	S. Mohanty		S. Mohanty
	Cisco Systems		Cisco Systems
	Expires: December 23, 2017 June 21, 2017		Expires: October 11, 2018 April 9, 2018
	Preference-based EVPN DF Election		Preference-based EVPN DF Election
	draft-ietf-bess-evpn-pref-df-00		draft-ietf-bess-evpn-pref-df-01
	Abstract		Abstract
	RFC7432 defines the Designated Forwarder (DF) in (PBB-)EVPN networks		RFC7432 defines the Designated Forwarder (DF) in (PBB-)EVPN networks
	as the PE responsible for sending broadcast, multicast and unknown		as the PE responsible for sending broadcast, multicast and unknown
	unicast traffic (BUM) to a multi-homed device/network in the case of		unicast traffic (BUM) to a multi-homed device/network in the case of
	an all-active multi-homing ES, or BUM and unicast in the case of		an all-active multi-homing ES, or BUM and unicast in the case of
	single-active multi-homing.		single-active multi-homing.
	The DF is selected out of a candidate list of PEs that advertise the		The DF is selected out of a candidate list of PEs that advertise the
	skipping to change at page 2, line 22 ¶		skipping to change at page 2, line 22 ¶
	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."
	The list of current Internet-Drafts can be accessed at		The list of current Internet-Drafts can be accessed at
	http://www.ietf.org/ietf/1id-abstracts.txt		http://www.ietf.org/ietf/1id-abstracts.txt
	The list of Internet-Draft Shadow Directories can be accessed at		The list of Internet-Draft Shadow Directories can be accessed at
	http://www.ietf.org/shadow.html		http://www.ietf.org/shadow.html
	This Internet-Draft will expire on December 23, 2017.		This Internet-Draft will expire on October 11, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2018 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
	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
	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
	skipping to change at page 2, line 48 ¶		skipping to change at page 2, line 48 ¶
	Table of Contents		Table of Contents
	1. Problem Statement . . . . . . . . . . . . . . . . . . . . . . . 3		1. Problem Statement . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Solution requirements . . . . . . . . . . . . . . . . . . . . . 3		2. Solution requirements . . . . . . . . . . . . . . . . . . . . . 3
	3. EVPN BGP Attributes for Deterministic DF Election . . . . . . . 4		3. EVPN BGP Attributes for Deterministic DF Election . . . . . . . 4
	4. Solution description . . . . . . . . . . . . . . . . . . . . . 5		4. Solution description . . . . . . . . . . . . . . . . . . . . . 5
	4.1 Use of the Preference algorithm . . . . . . . . . . . . . . 5		4.1 Use of the Preference algorithm . . . . . . . . . . . . . . 5
	4.2 Use of the Preference algorithm in RFC7432		4.2 Use of the Preference algorithm in RFC7432
	Ethernet-Segments . . . . . . . . . . . . . . . . . . . . . 7		Ethernet-Segments . . . . . . . . . . . . . . . . . . . . . 7
	4.3 The Non-Revertive option . . . . . . . . . . . . . . . . . . 7		4.3 The Non-Revertive option . . . . . . . . . . . . . . . . . . 8
	5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 10		5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 10
	11. Conventions used in this document . . . . . . . . . . . . . . 10		11. Conventions used in this document . . . . . . . . . . . . . . 10
	12. Security Considerations . . . . . . . . . . . . . . . . . . . 11		12. Security Considerations . . . . . . . . . . . . . . . . . . . 11
	13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11		13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
	15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11		15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
	15.1 Normative References . . . . . . . . . . . . . . . . . . . 11		15.1 Normative References . . . . . . . . . . . . . . . . . . . 11
	15.2 Informative References . . . . . . . . . . . . . . . . . . 11		15.2 Informative References . . . . . . . . . . . . . . . . . . 11
	16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11		16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11
	17. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11		17. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11
	17. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 11		17. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12
	1. Problem Statement		1. Problem Statement
	RFC7432 defines the Designated Forwarder (DF) in (PBB-)EVPN networks		RFC7432 defines the Designated Forwarder (DF) in (PBB-)EVPN networks
	as the PE responsible for sending broadcast, multicast and unknown		as the PE responsible for sending broadcast, multicast and unknown
	unicast traffic (BUM) to a multi-homed device/network in the case of		unicast traffic (BUM) to a multi-homed device/network in the case of
	an all-active multi-homing ES or BUM and unicast traffic to a multi-		an all-active multi-homing ES or BUM and unicast traffic to a multi-
	homed device or network in case of single-active multi-homing.		homed device or network in case of single-active multi-homing.
	The DF is selected out of a candidate list of PEs that advertise the		The DF is selected out of a candidate list of PEs that advertise the
	skipping to change at page 4, line 19 ¶		skipping to change at page 4, line 19 ¶
	even if the former DF PE comes back up after a failure. This is		even if the former DF PE comes back up after a failure. This is
	also known as "non-revertive" behavior, as opposed to the RFC7432		also known as "non-revertive" behavior, as opposed to the RFC7432
	DF election procedures that are always revertive.		DF election procedures that are always revertive.
	e) The solution MUST work for single-active and all-active multi-		e) The solution MUST work for single-active and all-active multi-
	homing Ethernet Segments.		homing Ethernet Segments.
	3. EVPN BGP Attributes for Deterministic DF Election		3. EVPN BGP Attributes for Deterministic DF Election
	This solution reuses and extends the DF Election Extended Community		This solution reuses and extends the DF Election Extended Community
	defined in [EVPN-HRW-DF] that is advertised along with the ES route:		defined in [DF] that is advertised along with the ES route:
	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=0x06 | Sub-Type(TBD) | DF Type |DP| Reserved=0 |		| Type=0x06 | Sub-Type(0x06)| DF Type |DP| Reserved=0 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved = 0 | DF Preference (2 octets) |		| Reserved = 0 | DF Preference (2 octets) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Where the following fields are re-defined as follows:		Where the following fields are re-defined as follows:
	o DF Type can have the following values:		o DF Type can have the following values:
	- Type 0 - Default, mod based DF election as per RFC7432.		- Type 0 - Default, mod based DF election as per RFC7432.
	- Type 1 - HRW algorithm as per [EVPN-HRW-DF]		- Type 1 - HRW algorithm as per [DF]
	- Type 2 - Preference algorithm (this document)		- Type 2 - Preference algorithm (this document)
	o DP or 'Don't Preempt' bit, determines if the PE advertising the ES		o DP or 'Don't Preempt' bit, determines if the PE advertising the ES
	route requests the remote PEs in the ES not to preempt it as DF.		route requests the remote PEs in the ES not to preempt it as DF.
	The default value is DP=0, which is compatible with the current		The default value is DP=0, which is compatible with the current
	'preempt' or 'revertive' behavior in RFC7432. The DP bit SHOULD be		'preempt' or 'revertive' behavior in RFC7432. The DP bit SHOULD be
	ignored if the DF Type is different than 2.		ignored if the DF Type is different than 2.
	o DF Preference defines a 2-octet value that indicates the PE		o DF Preference defines a 2-octet value that indicates the PE
	preference to become the DF in the ES. The allowed values are		preference to become the DF in the ES. The allowed values are
	within the range 0-65535, and default value MUST be 32767. This		within the range 0-65535, and default value MUST be 32767. This
	value is the midpoint in the allowed Preference range of values,		value is the midpoint in the allowed Preference range of values,
	which gives the operator the flexibility of choosing a significant		which gives the operator the flexibility of choosing a significant
	number of values, above or below the default Preference.		number of values, above or below the default Preference. The DF
			Preference field is specific to DF Type 2 and does not represent
			any Preference value for other Types.
	4. Solution description		4. Solution description
	Figure 1 illustrates an example that will be used in the description		Figure 1 illustrates an example that will be used in the description
	of the solution.		of the solution.
	EVPN network		EVPN network
	+-------------------+		+-------------------+
	| +-------+ ENNI Aggregation		| +-------+ ENNI Aggregation
	| <---ESI1,500 | PE1 | /\ +----Network---+		| <---ESI1,500 | PE1 | /\ +----Network---+
	skipping to change at page 7, line 48 ¶		skipping to change at page 7, line 48 ¶
	o Assuming ES3 is defined in PE1 and PE2, PE1 may be configured as		o Assuming ES3 is defined in PE1 and PE2, PE1 may be configured as
	[500,0,Preference] for ES3 and PE2 as [100,0,Preference].		[500,0,Preference] for ES3 and PE2 as [100,0,Preference].
	o In addition, assuming vlan-based service interfaces, the PEs will		o In addition, assuming vlan-based service interfaces, the PEs will
	be configured with (vlan/ISID-range,high_or_low), e.g. (1-		be configured with (vlan/ISID-range,high_or_low), e.g. (1-
	2000,high) and (2001-4000, low).		2000,high) and (2001-4000, low).
	o This will result in PE1 being DF for EVI/ISIDs 1-2000 and PE2 being		o This will result in PE1 being DF for EVI/ISIDs 1-2000 and PE2 being
	DF for EVI/ISIDs 2001-4000.		DF for EVI/ISIDs 2001-4000.
			For Ethernet Segments attached to three or more PEs, any other logic
			that provides a fair distribution of the DF function among the PEs is
			valid, as long as that logic is consistent in all the PEs in the ES.
	4.3 The Non-Revertive option		4.3 The Non-Revertive option
	As discussed in section 2(d), an option to NOT preempt the existing		As discussed in section 2(d), an option to NOT preempt the existing
	DF for a given EVI/ISID is required and therefore added to the DF		DF for a given EVI/ISID is required and therefore added to the DF
	Election extended community. This option will allow a non-revertive		Election extended community. This option will allow a non-revertive
	behavior in the DF election.		behavior in the DF election.
	Note that, when a given PE in an ES is taken down for maintenance		Note that, when a given PE in an ES is taken down for maintenance
	operations, before bringing it back, the Preference may be changed in		operations, before bringing it back, the Preference may be changed in
	order to provide a non-revertive behavior. The DP bit and the		order to provide a non-revertive behavior. The DP bit and the
	skipping to change at page 11, line 13 ¶		skipping to change at page 11, line 17 ¶
	listed above. This convention aids reviewers in quickly identifying		listed above. This convention aids reviewers in quickly identifying
	or finding the explicit compliance requirements of this RFC.		or finding the explicit compliance requirements of this RFC.
	12. Security Considerations		12. Security Considerations
	This section will be added in future versions.		This section will be added in future versions.
	13. IANA Considerations		13. IANA Considerations
	This document solicits the allocation of DF type = 2 in the registry		This document solicits the allocation of DF type = 2 in the registry
	created by [EVPN-HRW-DF] for the DF type field.		created by [DF] for the DF type field, and the DP bit in the [DF]
			Bitmap registry.
	15. References		15. References
	15.1 Normative References		15.1 Normative References
	[RFC7432]Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,		[RFC7432]Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
	Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet		Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet
	VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015, <http://www.rfc-		VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015,
	editor.org/info/rfc7432>.		<https://www.rfc-editor.org/info/rfc7432>.
			[DF] Rabadan J., Mohanty S. et al. "Framework for EVPN Designated
			Forwarder Election Extensibility", draft-ietf-bess-evpn-df-election-
			framework-00, work-in-progress, March 5, 2018.
	15.2 Informative References		15.2 Informative References
	[vES] Sajassi et al. "EVPN Virtual Ethernet Segment", draft-sajassi-		[vES] Sajassi et al. "EVPN Virtual Ethernet Segment", draft-sajassi-
	bess-evpn-virtual-eth-segment-01, work-in-progress, July 6, 2015.		bess-evpn-virtual-eth-segment-03, work-in-progress, August 26, 2018.
	[EVPN-HRW-DF] Mohanty S. et al. "A new Designated Forwarder Election
	for the EVPN", draft-mohanty-bess-evpn-df-election-02, work-in-
	progress, October 19, 2015.
	16. Acknowledgments		16. Acknowledgments
	The authors would like to thank Kishore Tiruveedhula for his review		The authors would like to thank Kishore Tiruveedhula for his review
	and comments.		and comments.
	17. Contributors		17. Contributors
	In addition to the authors listed, the following individuals also		In addition to the authors listed, the following individuals also
	contributed to this document:		contributed to this document:
	skipping to change at page 12, line 35 ¶		skipping to change at page 12, line 39 ¶
	Ali Sajassi		Ali Sajassi
	Cisco Systems, Inc.		Cisco Systems, Inc.
	Email: sajassi@cisco.com		Email: sajassi@cisco.com
	Satya Ranjan Mohanty		Satya Ranjan Mohanty
	Cisco Systems, Inc.		Cisco Systems, Inc.
	Email: satyamoh@cisco.com		Email: satyamoh@cisco.com
	Sami Boutros		Sami Boutros
	VMware, Inc.		Email: boutros.sami@gmail.com
	Email: sboutros@vmware.com
End of changes. 16 change blocks.
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