draft-ietf-ipsecme-failure-detection-00.txt		draft-ietf-ipsecme-failure-detection-01.txt
	IPsecME Working Group Y. Nir, Ed.		IPsecME Working Group Y. Nir, Ed.
	Internet-Draft Check Point		Internet-Draft Check Point
	Intended status: Standards Track D. Wierbowski		Intended status: Standards Track D. Wierbowski
	Expires: March 7, 2011 IBM		Expires: April 13, 2011 IBM
	September 3, 2010		F. Detienne
			P. Sethi
			Cisco
			October 10, 2010
	A Quick Crash Detection Method for IKE		A Quick Crash Detection Method for IKE
	draft-ietf-ipsecme-failure-detection-00		draft-ietf-ipsecme-failure-detection-01
	Abstract		Abstract
	This document describes an extension to the IKEv2 protocol that		This document describes an extension to the IKEv2 protocol that
	allows for faster detection of SA desynchronization using a saved		allows for faster detection of SA desynchronization using a saved
	token.		token.
	When an IPsec tunnel between two IKEv2 peers is disconnected due to a		When an IPsec tunnel between two IKEv2 peers is disconnected due to a
	restart of one peer, it can take as much as several minutes for the		restart of one peer, it can take as much as several minutes for the
	other peer to discover that the reboot has occurred, thus delaying		other peer to discover that the reboot has occurred, thus delaying
	skipping to change at page 1, line 39		skipping to change at page 1, line 42
	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 March 7, 2011.		This Internet-Draft will expire on April 13, 2011.
	Copyright Notice		Copyright Notice
	Copyright (c) 2010 IETF Trust and the persons identified as the		Copyright (c) 2010 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 3, line 16		skipping to change at page 3, line 16
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
	1.1. Conventions Used in This Document . . . . . . . . . . . . 4		1.1. Conventions Used in This Document . . . . . . . . . . . . 4
	2. RFC 4306 Crash Recovery . . . . . . . . . . . . . . . . . . . 5		2. RFC 4306 Crash Recovery . . . . . . . . . . . . . . . . . . . 5
	3. Protocol Outline . . . . . . . . . . . . . . . . . . . . . . . 5		3. Protocol Outline . . . . . . . . . . . . . . . . . . . . . . . 5
	4. Formats and Exchanges . . . . . . . . . . . . . . . . . . . . 6		4. Formats and Exchanges . . . . . . . . . . . . . . . . . . . . 6
	4.1. Notification Format . . . . . . . . . . . . . . . . . . . 6		4.1. Notification Format . . . . . . . . . . . . . . . . . . . 6
	4.2. Passing a Token in the AUTH Exchange . . . . . . . . . . . 7		4.2. Passing a Token in the AUTH Exchange . . . . . . . . . . . 7
	4.3. Replacing Tokens After Rekey or Resumption . . . . . . . . 8		4.3. Replacing Tokens After Rekey or Resumption . . . . . . . . 8
	4.4. Replacing the Token for an Existing SA . . . . . . . . . . 9		4.4. Replacing the Token for an Existing SA . . . . . . . . . . 9
	4.5. Presenting the Token in an INFORMATIONAL Exchange . . . . 9		4.5. Presenting the Token in an Unprotected Message . . . . . . 9
	5. Token Generation and Verification . . . . . . . . . . . . . . 10		5. Token Generation and Verification . . . . . . . . . . . . . . 10
	5.1. A Stateless Method of Token Generation . . . . . . . . . . 10		5.1. A Stateless Method of Token Generation . . . . . . . . . . 10
	5.2. A Stateless Method with IP addresses . . . . . . . . . . . 11		5.2. A Stateless Method with IP addresses . . . . . . . . . . . 11
	5.3. Token Lifetime . . . . . . . . . . . . . . . . . . . . . . 11		5.3. Token Lifetime . . . . . . . . . . . . . . . . . . . . . . 11
	6. Backup Gateways . . . . . . . . . . . . . . . . . . . . . . . 11		6. Backup Gateways . . . . . . . . . . . . . . . . . . . . . . . 11
	7. Alternative Solutions . . . . . . . . . . . . . . . . . . . . 12		7. Alternative Solutions . . . . . . . . . . . . . . . . . . . . 12
	7.1. Initiating a new IKE SA . . . . . . . . . . . . . . . . . 12		7.1. Initiating a new IKE SA . . . . . . . . . . . . . . . . . 12
	7.2. SIR . . . . . . . . . . . . . . . . . . . . . . . . . . . 12		7.2. SIR . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
	7.3. Birth Certificates . . . . . . . . . . . . . . . . . . . . 12		7.3. Birth Certificates . . . . . . . . . . . . . . . . . . . . 12
	7.4. Reducing Liveness Check Length . . . . . . . . . . . . . . 13		7.4. Reducing Liveness Check Length . . . . . . . . . . . . . . 13
	8. Interaction with Session Resumption . . . . . . . . . . . . . 13		8. Interaction with Session Resumption . . . . . . . . . . . . . 13
	9. Operational Considerations . . . . . . . . . . . . . . . . . . 15		9. Operational Considerations . . . . . . . . . . . . . . . . . . 15
	9.1. Who should implement this specification . . . . . . . . . 15		9.1. Who should implement this specification . . . . . . . . . 15
	9.2. Response to unknown child SPI . . . . . . . . . . . . . . 16		9.2. Response to unknown child SPI . . . . . . . . . . . . . . 16
	9.3. Using Tokens that Depend on IP Addresses . . . . . . . . . 16		10. Security Considerations . . . . . . . . . . . . . . . . . . . 16
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 17
	10.1. QCD Token Generation and Handling . . . . . . . . . . . . 17		10.1. QCD Token Generation and Handling . . . . . . . . . . . . 17
	10.2. QCD Token Transmission . . . . . . . . . . . . . . . . . . 18		10.2. QCD Token Transmission . . . . . . . . . . . . . . . . . . 17
	10.3. QCD Token Enumeration . . . . . . . . . . . . . . . . . . 18		10.3. QCD Token Enumeration . . . . . . . . . . . . . . . . . . 18
			10.4. Selecting an Appropriate Token Generation Method . . . . . 18
	11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
	12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19		12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19
	13. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . 19		13. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . 19
	13.1. Changes from draft-nir-ike-qcd-07 . . . . . . . . . . . . 19		13.1. Changes from draft-ietf-ipsecme-failure-detection-00 . . . 19
	13.2. Changes from draft-nir-ike-qcd-03 and -04 . . . . . . . . 19		13.2. Changes from draft-nir-ike-qcd-07 . . . . . . . . . . . . 20
	13.3. Changes from draft-nir-ike-qcd-02 . . . . . . . . . . . . 19		13.3. Changes from draft-nir-ike-qcd-03 and -04 . . . . . . . . 20
	13.4. Changes from draft-nir-ike-qcd-01 . . . . . . . . . . . . 20		13.4. Changes from draft-nir-ike-qcd-02 . . . . . . . . . . . . 20
	13.5. Changes from draft-nir-ike-qcd-00 . . . . . . . . . . . . 20		13.5. Changes from draft-nir-ike-qcd-01 . . . . . . . . . . . . 20
	13.6. Changes from draft-nir-qcr-00 . . . . . . . . . . . . . . 20		13.6. Changes from draft-nir-ike-qcd-00 . . . . . . . . . . . . 20
	14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20		13.7. Changes from draft-nir-qcr-00 . . . . . . . . . . . . . . 20
	14.1. Normative References . . . . . . . . . . . . . . . . . . . 20		14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21
	14.2. Informative References . . . . . . . . . . . . . . . . . . 20		14.1. Normative References . . . . . . . . . . . . . . . . . . . 21
			14.2. Informative References . . . . . . . . . . . . . . . . . . 21
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
	1. Introduction		1. Introduction
	IKEv2, as described in [IKEv2bis] and its predecessor RFC 4306, has a		IKEv2, as described in [RFC5996] and its predecessor RFC 4306, has a
	method for recovering from a reboot of one peer. As long as traffic		method for recovering from a reboot of one peer. As long as traffic
	flows in both directions, the rebooted peer should re-establish the		flows in both directions, the rebooted peer should re-establish the
	tunnels immediately. However, in many cases the rebooted peer is a		tunnels immediately. However, in many cases the rebooted peer is a
	VPN gateway that protects only servers, or else the non-rebooted peer		VPN gateway that protects only servers, or else the non-rebooted peer
	has a dynamic IP address. In such cases, the rebooted peer will not		has a dynamic IP address. In such cases, the rebooted peer will not
	be able to re-establish the tunnels. Section 2 describes how		be able to re-establish the tunnels. Section 2 describes how
	recovery works under RFC 4306, and explains why it may take several		recovery works under RFC 4306, and explains why it may take several
	minutes.		minutes.
	The method proposed here, is to send an octet string, called a "QCD		The method proposed here, is to send an octet string, called a "QCD
	skipping to change at page 5, line 11		skipping to change at page 5, line 11
	database. A small non-volatile storage module is required for a		database. A small non-volatile storage module is required for a
	token maker, but a larger one can be used to enhance performance, as		token maker, but a larger one can be used to enhance performance, as
	described in Section 9.2.		described in Section 9.2.
	2. RFC 4306 Crash Recovery		2. RFC 4306 Crash Recovery
	When one peer loses state or reboots, the other peer does not get any		When one peer loses state or reboots, the other peer does not get any
	notification, so unidirectional IPsec traffic can still flow. The		notification, so unidirectional IPsec traffic can still flow. The
	rebooted peer will not be able to decrypt it, however, and the only		rebooted peer will not be able to decrypt it, however, and the only
	remedy is to send an unprotected INVALID_SPI notification as		remedy is to send an unprotected INVALID_SPI notification as
	described in section 3.10.1 of [IKEv2bis]. That section also		described in section 3.10.1 of [RFC5996]. That section also
	describes the processing of such a notification:		describes the processing of such a notification:
	"If this Informational Message is sent outside the		"If this Informational Message is sent outside the
	context of an IKE_SA, it should be used by the recipient		context of an IKE_SA, it should be used by the recipient
	only as a "hint" that something might be wrong (because it		only as a "hint" that something might be wrong (because it
	could easily be forged)."		could easily be forged)."
	Since the INVALID_SPI can only be used as a hint, the non-rebooted		Since the INVALID_SPI can only be used as a hint, the non-rebooted
	peer has to determine whether the IPsec SA, and indeed the parent IKE		peer has to determine whether the IPsec SA, and indeed the parent IKE
	SA are still valid. The method of doing this is described in section		SA are still valid. The method of doing this is described in section
	2.4 of [IKEv2bis]. This method, called "liveness check" involves		2.4 of [RFC5996]. This method, called "liveness check" involves
	sending a protected empty INFORMATIONAL message, and awaiting a		sending a protected empty INFORMATIONAL message, and awaiting a
	response. This procedure is sometimes referred to as "Dead Peer		response. This procedure is sometimes referred to as "Dead Peer
	Detection" or DPD.		Detection" or DPD.
	Section 2.4 does not mandate how many times the liveness check		Section 2.4 does not mandate how many times the liveness check
	message should be retransmitted, or for how long, but does recommend		message should be retransmitted, or for how long, but does recommend
	the following:		the following:
	"It is		"It is
	suggested that messages be retransmitted at least a dozen times over		suggested that messages be retransmitted at least a dozen times over
	a period of at least several minutes before giving up on an SA..."		a period of at least several minutes before giving up on an SA..."
	Those "at least several minutes" are a time during which both peers		Those "at least several minutes" are a time during which both peers
	are active, but IPsec cannot be used.		are active, but IPsec cannot be used.
	3. Protocol Outline		3. Protocol Outline
	Supporting implementations will send a notification, called a "QCD		Supporting implementations will send a notification, called a "QCD
	token", as described in Section 4.1 in the last IKE_AUTH exchange		token", as described in Section 4.1 in the first IKE_AUTH exchange
	messages. These are the final IKE_AUTH request and final IKE_AUTH		messages. These are the final IKE_AUTH request and final IKE_AUTH
	response that contain the AUTH payloads. The generation of these		response that contain the AUTH payloads. The generation of these
	tokens is a local matter for implementations, but considerations are		tokens is a local matter for implementations, but considerations are
	described in Section 5. Implementations that send such a token will		described in Section 5. Implementations that send such a token will
	be called "token makers".		be called "token makers".
	A supporting implementation receiving such a token MUST store it (or		A supporting implementation receiving such a token MUST store it (or
	a digest thereof) along with the IKE SA. Implementations that		a digest thereof) along with the IKE SA. Implementations that
	support this part of the protocol will be called "token takers".		support this part of the protocol will be called "token takers".
	Section 9.1 has considerations for which implementations need to be		Section 9.1 has considerations for which implementations need to be
	skipping to change at page 6, line 17		skipping to change at page 6, line 17
	When a token maker receives a protected IKE request message with		When a token maker receives a protected IKE request message with
	unknown IKE SPIs, it SHOULD generate a new token that is identical to		unknown IKE SPIs, it SHOULD generate a new token that is identical to
	the previous token, and send it to the requesting peer in an		the previous token, and send it to the requesting peer in an
	unprotected IKE message as described in Section 4.5.		unprotected IKE message as described in Section 4.5.
	When a token taker receives the QCD token in an unprotected		When a token taker receives the QCD token in an unprotected
	notification, it MUST verify that the TOKEN_SECRET_DATA matches the		notification, it MUST verify that the TOKEN_SECRET_DATA matches the
	token stored with the matching IKE SA. If the verification fails, or		token stored with the matching IKE SA. If the verification fails, or
	if the IKE SPIs in the message do not match any existing IKE SA, it		if the IKE SPIs in the message do not match any existing IKE SA, it
	SHOULD log the event. If it succeeds, it MUST silently delete the		SHOULD log the event. If it succeeds, it MUST silently delete the
	IKE SA associated with the IKE_SPI fields, and all dependant child		IKE SA associated with the IKE_SPI fields, and all dependent child
	SAs. This event MAY also be logged. The token taker MUST accept		SAs. This event MAY also be logged. The token taker MUST accept
	such tokens from any IP address and port combination, so as to allow		such tokens from any IP address and port combination, so as to allow
	different kinds of high-availability configurations of the token		different kinds of high-availability configurations of the token
	maker.		maker.
	A supporting token taker MAY immediately create new SAs using an		A supporting token taker MAY immediately create new SAs using an
	Initial exchange, or it may wait for subsequent traffic to trigger		Initial exchange, or it may wait for subsequent traffic to trigger
	the creation of new SAs.		the creation of new SAs.
	See Section 8 for a short discussion about this extensions's		See Section 8 for a short discussion about this extensions's
	skipping to change at page 7, line 6		skipping to change at page 7, line 6
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! !		! !
	~ TOKEN_SECRET_DATA ~		~ TOKEN_SECRET_DATA ~
	! !		! !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	o Protocol ID (1 octet) MUST be 1, as this message is related to an		o Protocol ID (1 octet) MUST be 1, as this message is related to an
	IKE SA.		IKE SA.
	o SPI Size (1 octet) MUST be zero, in conformance with section 3.10		o SPI Size (1 octet) MUST be zero, in conformance with section 3.10
	of [IKEv2bis].		of [RFC5996].
	o QCD Token Notify Message Type (2 octets) - MUST be xxxxx, the		o QCD Token Notify Message Type (2 octets) - MUST be xxxxx, the
	value assigned for QCD token notifications. TBA by IANA.		value assigned for QCD token notifications. TBA by IANA.
	o TOKEN_SECRET_DATA (16-128 octets) contains a generated token as		o TOKEN_SECRET_DATA (16-128 octets) contains a generated token as
	described in Section 5.		described in Section 5.
	4.2. Passing a Token in the AUTH Exchange		4.2. Passing a Token in the AUTH Exchange
	For brevity, only the EAP version of an AUTH exchange will be		For brevity, only the EAP version of an AUTH exchange will be
	presented here. The non-EAP version is very similar. The figures		presented here. The non-EAP version is very similar. The figures
	below are based on appendix C.3 of [IKEv2bis].		below are based on appendix C.3 of [RFC5996].
	first request --> IDi,		first request --> IDi,
	[N(INITIAL_CONTACT)],		[N(INITIAL_CONTACT)],
	[[N(HTTP_CERT_LOOKUP_SUPPORTED)], CERTREQ+],		[[N(HTTP_CERT_LOOKUP_SUPPORTED)], CERTREQ+],
	[IDr],		[IDr],
			[N(QCD_TOKEN)]
	[CP(CFG_REQUEST)],		[CP(CFG_REQUEST)],
	[N(IPCOMP_SUPPORTED)+],		[N(IPCOMP_SUPPORTED)+],
	[N(USE_TRANSPORT_MODE)],		[N(USE_TRANSPORT_MODE)],
	[N(ESP_TFC_PADDING_NOT_SUPPORTED)],		[N(ESP_TFC_PADDING_NOT_SUPPORTED)],
	[N(NON_FIRST_FRAGMENTS_ALSO)],		[N(NON_FIRST_FRAGMENTS_ALSO)],
	SA, TSi, TSr,		SA, TSi, TSr,
	[V+]		[V+]
	first response <-- IDr, [CERT+], AUTH,		first response <-- IDr, [CERT+], AUTH,
	EAP,		EAP,
	[V+]		[V+]
	/ --> EAP		/ --> EAP
	repeat 1..N times |		repeat 1..N times |
	\ <-- EAP		\ <-- EAP
	last request --> AUTH		last request --> AUTH
	[N(QCD_TOKEN)]
	last response <-- AUTH,		last response <-- AUTH,
	[N(QCD_TOKEN)]		[N(QCD_TOKEN)]
	[CP(CFG_REPLY)],		[CP(CFG_REPLY)],
	[N(IPCOMP_SUPPORTED)],		[N(IPCOMP_SUPPORTED)],
	[N(USE_TRANSPORT_MODE)],		[N(USE_TRANSPORT_MODE)],
	[N(ESP_TFC_PADDING_NOT_SUPPORTED)],		[N(ESP_TFC_PADDING_NOT_SUPPORTED)],
	[N(NON_FIRST_FRAGMENTS_ALSO)],		[N(NON_FIRST_FRAGMENTS_ALSO)],
	SA, TSi, TSr,		SA, TSi, TSr,
	[N(ADDITIONAL_TS_POSSIBLE)],		[N(ADDITIONAL_TS_POSSIBLE)],
	skipping to change at page 8, line 13		skipping to change at page 8, line 13
	Note that the QCD_TOKEN notification is marked as optional because it		Note that the QCD_TOKEN notification is marked as optional because it
	is not required by this specification that every implementation be		is not required by this specification that every implementation be
	both token maker and token taker. If only one peer sends the QCD		both token maker and token taker. If only one peer sends the QCD
	token, then a reboot of the other peer will not be recoverable by		token, then a reboot of the other peer will not be recoverable by
	this method. This may be acceptable if traffic typically originates		this method. This may be acceptable if traffic typically originates
	from the other peer.		from the other peer.
	In any case, the lack of a QCD_TOKEN notification MUST NOT be taken		In any case, the lack of a QCD_TOKEN notification MUST NOT be taken
	as an indication that the peer does not support this standard.		as an indication that the peer does not support this standard.
	Conversely, if a peer does not understand this notification, it will		Conversely, if a peer does not understand this notification, it will
	simply ignore it. Therefore a peer MAY send this notification		simply ignore it. Therefore a peer may send this notification
	freely, even if it does not know whether the other side supports it.		freely, even if it does not know whether the other side supports it.
	The QCD_TOKEN notification is related to the IKE SA and MUST follow		The QCD_TOKEN notification is related to the IKE SA and MUST follow
	the AUTH payload and precede the Configuration payload and all		the AUTH payload and precede the Configuration payload and all
	payloads related to the child SA.		payloads related to the child SA.
	4.3. Replacing Tokens After Rekey or Resumption		4.3. Replacing Tokens After Rekey or Resumption
	After rekeying an IKE SA, the IKE SPIs are replaced, so the new SA		After rekeying an IKE SA, the IKE SPIs are replaced, so the new SA
	also needs to have a token. If only the responder in the rekey		also needs to have a token. If only the responder in the rekey
	skipping to change at page 9, line 39		skipping to change at page 9, line 39
	HDR, SK { N(COOKIE2), [N(QCD_TOKEN)] }		HDR, SK { N(COOKIE2), [N(QCD_TOKEN)] }
	(IP_I2:4500 -> IP_R1:4500)		(IP_I2:4500 -> IP_R1:4500)
	HDR, SK { N(COOKIE2), [N(QCD_TOKEN)] } -->		HDR, SK { N(COOKIE2), [N(QCD_TOKEN)] } -->
	A token taker MUST accept such gratuitous QCD_TOKEN notifications as		A token taker MUST accept such gratuitous QCD_TOKEN notifications as
	long as they are carried in protected exchanges. A token maker		long as they are carried in protected exchanges. A token maker
	SHOULD NOT generate them unless it is no longer able to generate the		SHOULD NOT generate them unless it is no longer able to generate the
	old QCD_TOKEN.		old QCD_TOKEN.
	4.5. Presenting the Token in an INFORMATIONAL Exchange		4.5. Presenting the Token in an Unprotected Message
	This QCD_TOKEN notification is unprotected, and is sent as a response		This QCD_TOKEN notification is unprotected, and is sent as a response
	to a protected IKE request, which uses an IKE SA that is unknown.		to a protected IKE request, which uses an IKE SA that is unknown.
	request --> N(INVALID_IKE_SPI), N(QCD_TOKEN)+		request --> N(INVALID_IKE_SPI), N(QCD_TOKEN)+
	If child SPIs are persistently mapped to IKE SPIs as described in		If child SPIs are persistently mapped to IKE SPIs as described in
	Section 9.2, a token taker may get the following unprotected message		Section 9.2, a token taker may get the following unprotected message
	in response to an ESP or AH packet.		in response to an ESP or AH packet.
	request --> N(INVALID_SPI), N(QCD_TOKEN)+		request --> N(INVALID_SPI), N(QCD_TOKEN)+
	The QCD_TOKEN and INVALID_IKE_SPI notifications are sent together to		The QCD_TOKEN and INVALID_IKE_SPI notifications are sent together to
	support both implementations that conform to this specification and		support both implementations that conform to this specification and
	implementations that don't. Similar to the description in section		implementations that don't. Similar to the description in section
	2.21 of [IKEv2bis], The IKE SPI and message ID fields in the packet		2.21 of [RFC5996], the IKE SPI and message ID fields in the packet
	headers are taken from the protected IKE request.		headers are taken from the protected IKE request.
	To support a periodic rollover of the secret used for token		To support a periodic rollover of the secret used for token
	generation, the token taker MUST support at least four QCD_TOKEN		generation, the token taker MUST support at least four QCD_TOKEN
	notifications in a single packet. The token is considered verified		notifications in a single packet. The token is considered verified
	if any of the QCD_TOKEN notifications matches. The token maker MAY		if any of the QCD_TOKEN notifications matches. The token maker MAY
	generate up to four QCD_TOKEN notifications, based on several		generate up to four QCD_TOKEN notifications, based on several
	generations of keys.		generations of keys.
	If the QCD_TOKEN verifies OK, an empty response MUST be sent. If the		If the QCD_TOKEN verifies OK, the receiver MUST silently discard the
	QCD_TOKEN cannot be validated, a response MUST NOT be sent.		IKE SA and all associated child SAs. If the QCD_TOKEN cannot be
			validated, a response MUST NOT be sent, and the event may be logged.
	Section 5 defines token verification.		Section 5 defines token verification.
	5. Token Generation and Verification		5. Token Generation and Verification
	No token generation method is mandated by this document. Two method		No token generation method is mandated by this document. Two methods
	are documented in the following sub-sections, but they only serve as		are documented in the following sub-sections, but they only serve as
	examples.		examples.
	The following lists the requirements from a token generation		The following lists the requirements for a token generation
	mechanism:		mechanism:
	o Tokens MUST be at least 16 octets long, and no more than 128		o Tokens MUST be at least 16 octets long, and no more than 128
	octets long, to facilitate storage and transmission. Tokens		octets long, to facilitate storage and transmission. Tokens
	SHOULD be indistinguishable from random data.		SHOULD be indistinguishable from random data.
	o It should not be possible for an external attacker to guess the		o It should not be possible for an external attacker to guess the
	QCD token generated by an implementation. Cryptographic		QCD token generated by an implementation. Cryptographic
	mechanisms such as PRNG and hash functions are RECOMMENDED.		mechanisms such as PRNG and hash functions are RECOMMENDED.
	o The token maker, MUST be able to re-generate or retrieve the token		o The token maker MUST be able to re-generate or retrieve the token
	based on the IKE SPIs even after it reboots.		based on the IKE SPIs even after it reboots.
	o The method of token generation MUST be such, that a collision of		o The method of token generation MUST be such that a collision of
	QCD tokens between different pairs of IKE SPI will be highly		QCD tokens between different pairs of IKE SPI will be highly
	unlikely.		unlikely.
	5.1. A Stateless Method of Token Generation		5.1. A Stateless Method of Token Generation
	This describes a stateless method of generating a token:		This describes a stateless method of generating a token:
	o At installation or immediately after the first boot of the token		o At installation or immediately after the first boot of the token
	maker, 32 random octets are generated using a secure random number		maker, 32 random octets are generated using a secure random number
	generator or a PRNG.		generator or a PRNG.
	o Those 32 bytes, called the "QCD_SECRET", are stored in non-		o Those 32 bytes, called the "QCD_SECRET", are stored in non-
	skipping to change at page 11, line 22		skipping to change at page 11, line 22
	TOKEN_SECRET_DATA = HASH(QCD_SECRET | SPI-I | SPI-R)		TOKEN_SECRET_DATA = HASH(QCD_SECRET | SPI-I | SPI-R)
	5.2. A Stateless Method with IP addresses		5.2. A Stateless Method with IP addresses
	This method is similar to the one in the previous section, except		This method is similar to the one in the previous section, except
	that the IP address of the token taker is also added to the block		that the IP address of the token taker is also added to the block
	being hashed. This has the disadvantage that the token needs to be		being hashed. This has the disadvantage that the token needs to be
	replaced (as described in Section 4.4) whenever the token taker		replaced (as described in Section 4.4) whenever the token taker
	changes its address.		changes its address.
	The reason to use this method is described in Section 9.3. When		The reason to use this method is described in Section 10.4. When
	using this method, the TOKEN_SECRET_DATA field is calculated as		using this method, the TOKEN_SECRET_DATA field is calculated as
	follows:		follows:
	TOKEN_SECRET_DATA = HASH(QCD_SECRET | SPI-I | SPI-R | IPaddr-T)		TOKEN_SECRET_DATA = HASH(QCD_SECRET | SPI-I | SPI-R | IPaddr-T)
	The IPaddr-T field specifies the IP address of the token taker.		The IPaddr-T field specifies the IP address of the token taker.
	Secret rollover considerations are similar to those in the previous		Secret rollover considerations are similar to those in the previous
	section.		section.
	5.3. Token Lifetime		5.3. Token Lifetime
	skipping to change at page 11, line 44		skipping to change at page 11, line 44
	The token is associated with a single IKE SA, and SHOULD be deleted		The token is associated with a single IKE SA, and SHOULD be deleted
	by the token taker when the SA is deleted or expires. More formally,		by the token taker when the SA is deleted or expires. More formally,
	the token is associated with the pair (SPI-I, SPI-R).		the token is associated with the pair (SPI-I, SPI-R).
	6. Backup Gateways		6. Backup Gateways
	Making crash detection and recovery quick is a worthy goal, but since		Making crash detection and recovery quick is a worthy goal, but since
	rebooting a gateway takes a non-zero amount of time, many		rebooting a gateway takes a non-zero amount of time, many
	implementations choose to have a stand-by gateway ready to take over		implementations choose to have a stand-by gateway ready to take over
	as soon as the primary gateway fails for any reason. [cluster]		as soon as the primary gateway fails for any reason. [cluster]
	describes consideration for such clusters of gateways with		describes considerations for such clusters of gateways with
	synchronized state, but the rest of this section is relevant even		synchronized state, but the rest of this section is relevant even
	when there is no synchnorized state.		when there is no synchronized state.
	If such a configuration is available, it is RECOMMENDED that the		If such a configuration is available, it is RECOMMENDED that the
	stand-by gateway be able to generate the same token as the active		stand-by gateway be able to generate the same token as the active
	gateway. if the method described in Section 5.1 is used, this means		gateway. if the method described in Section 5.1 is used, this means
	that the QCD_SECRET field is identical in both gateways. This has		that the QCD_SECRET field is identical in both gateways. This has
	the effect of having the crash recovery available immediately.		the effect of having the crash recovery available immediately.
	Note that this refers to "high availability" configurations, where		Note that this refers to "high availability" configurations, where
	only one gateway is active at any given moment. This is different		only one gateway is active at any given moment. This is different
	from "load sharing" configurations where more than one gateway is		from "load sharing" configurations where more than one gateway is
	skipping to change at page 14, line 10		skipping to change at page 14, line 10
	up a new IKE SA consume less computing resources. This is		up a new IKE SA consume less computing resources. This is
	particularly useful in the case of a remote access gateway that has		particularly useful in the case of a remote access gateway that has
	many tunnels. A failure of such a gateway would require all these		many tunnels. A failure of such a gateway would require all these
	many remote access clients to establish an IKE SA either with the		many remote access clients to establish an IKE SA either with the
	rebooted gateway or with a backup gateway. This tunnel re-		rebooted gateway or with a backup gateway. This tunnel re-
	establishment should occur within a short period of time, creating a		establishment should occur within a short period of time, creating a
	burden on the remote access gateway. Session Resumption addresses		burden on the remote access gateway. Session Resumption addresses
	this problem by having the clients store an encrypted derivative of		this problem by having the clients store an encrypted derivative of
	the IKE SA for quick re-establishment.		the IKE SA for quick re-establishment.
	What Session Resumption does not help, is the problem of detecting		What Session Resumption does not help is the problem of detecting
	that the peer gateway has failed. A failed gateway may go undetected		that the peer gateway has failed. A failed gateway may go undetected
	for as long as the lifetime of a child SA, because IPsec does not		for as long as the lifetime of a child SA, because IPsec does not
	have packet acknowledgement, and applications cannot signal the IPsec		have packet acknowledgement, and applications cannot signal the IPsec
	layer that the tunnel "does not work". Before establishing a new IKE		layer that the tunnel "does not work". Before establishing a new IKE
	SA using Session Resumption, a client should ascertain that the		SA using Session Resumption, a client should ascertain that the
	gateway has indeed failed. This could be done using either a		gateway has indeed failed. This could be done using either a
	liveness check (as in RFC 4306) or using the QCD tokens described in		liveness check (as in RFC 4306) or using the QCD tokens described in
	this document.		this document.
	A remote access client conforming to both specifications will store		A remote access client conforming to both specifications will store
	skipping to change at page 15, line 50		skipping to change at page 15, line 50
	of this protocol extension is reduced. For this reason critical		of this protocol extension is reduced. For this reason critical
	systems should implement backup gateways as described in Section 6.		systems should implement backup gateways as described in Section 6.
	Implementing the "token maker" side of QCD makes sense for IKE		Implementing the "token maker" side of QCD makes sense for IKE
	implementation where protected connections originate from the peer,		implementation where protected connections originate from the peer,
	such as inter-domain VPNs and remote access gateways. Implementing		such as inter-domain VPNs and remote access gateways. Implementing
	the "token taker" side of QCD makes sense for IKE implementations		the "token taker" side of QCD makes sense for IKE implementations
	where protected connections originate, such as inter-domain VPNs and		where protected connections originate, such as inter-domain VPNs and
	remote access clients.		remote access clients.
	To clarify the requirements:		To clarify the this discussion:
	o A remote-access client MUST be a token taker and MAY be a token		o For remote-access clients it makes sense to implement the token
	maker.		taker role.
	o A remote-access gateway MAY be a token taker and MUST be a token		o For remote-access gateways it makes sense to implement the token
	maker.		maker role.
	o An inter-domain VPN gateway MUST be both token maker and token		o For inter-domain VPN gateway it makes sense to implement both
	taker.		roles, because it can't be known in advance where the traffic
			originates.
			o It is perfectly valid to implement both roles in any case, for
			example when using a single library or a single gateway to perform
			several roles.
	In order to limit the effects of DoS attacks, a token taker SHOULD		In order to limit the effects of DoS attacks, a token taker SHOULD
	limit the rate of QCD_TOKENs verified from a particular source.		limit the rate of QCD_TOKENs verified from a particular source.
	If excessive amounts of IKE requests protected with unknown IKE SPIs		If excessive amounts of IKE requests protected with unknown IKE SPIs
	arrive at a token maker, the IKE module SHOULD revert to the behavior		arrive at a token maker, the IKE module SHOULD revert to the behavior
	described in section 2.21 of [IKEv2bis] and either send an		described in section 2.21 of [RFC5996] and either send an
	INVALID_IKE_SPI notification, or ignore it entirely.		INVALID_IKE_SPI notification, or ignore it entirely.
	9.2. Response to unknown child SPI		9.2. Response to unknown child SPI
	After a reboot, it is more likely that an implementation receives		After a reboot, it is more likely that an implementation receives
	IPsec packets than IKE packets. In that case, the rebooted		IPsec packets than IKE packets. In that case, the rebooted
	implementation will send an INVALID_SPI notification, triggering a		implementation will send an INVALID_SPI notification, triggering a
	liveness check. The token will only be sent in a response to the		liveness check. The token will only be sent in a response to the
	liveness check, thus requiring an extra round-trip.		liveness check, thus requiring an extra round-trip.
	skipping to change at page 16, line 44		skipping to change at page 16, line 48
	QCD token that arrives with an INVALID_SPI notification the same as		QCD token that arrives with an INVALID_SPI notification the same as
	if it arrived with the IKE SPIs of the parent IKE SA.		if it arrived with the IKE SPIs of the parent IKE SA.
	However, a persistent storage module might not be updated in a timely		However, a persistent storage module might not be updated in a timely
	manner, and could be populated with tokens relating to IKE SPIs that		manner, and could be populated with tokens relating to IKE SPIs that
	have already been rekeyed. A token taker MUST NOT take an invalid		have already been rekeyed. A token taker MUST NOT take an invalid
	QCD Token sent along with an INVALID_SPI notification as evidence		QCD Token sent along with an INVALID_SPI notification as evidence
	that the peer is either malfunctioning or attacking, but it SHOULD		that the peer is either malfunctioning or attacking, but it SHOULD
	limit the rate at which such notifications are processed.		limit the rate at which such notifications are processed.
	9.3. Using Tokens that Depend on IP Addresses
	This section describes the rationale for token generation methods
	such as the one described in Section 5.2. Note that this section
	merely provides a possible rationale, and does not specify or
	recommend any kind of configuration.
	Some configurations of security gateway use a load-sharing cluster of
	hosts, all sharing the same IP addresses, where the SAs (IKE and
	child) are not synchronized between the cluster members. In such a
	configuration, a single member does not know about all the IKE SAs
	that are active for the configuration. A load balancer (usually a
	networking switch) sends IKE and IPsec packets to the several members
	based on source IP address.
	In such a configuration, an attacker can send a forged protected IKE
	packet with the IKE SPIs of an existing IKE SA, but from a different
	IP address. This packet will likely be processed by a different
	cluster member from the one that owns the IKE SA. Since no IKE SA
	state is stored on this member, it will send a QCD token to the
	attacker. If the QCD token does not depend on IP address, this token
	can immediately be used to tell the token taker to tear down the IKE
	SA using an unprotected QCD_TOKEN notification.
	To thwart this possible attack, such configurations should use a
	method that considers the taker's IP address, such as the method
	described in Section 5.2.
	10. Security Considerations		10. Security Considerations
	10.1. QCD Token Generation and Handling		10.1. QCD Token Generation and Handling
	Tokens MUST be hard to guess. This is critical, because if an		Tokens MUST be hard to guess. This is critical, because if an
	attacker can guess the token associated with an IKE SA, she can tear		attacker can guess the token associated with an IKE SA, she can tear
	down the IKE SA and associated tunnels at will. When the token is		down the IKE SA and associated tunnels at will. When the token is
	delivered in the IKE_AUTH exchange, it is encrypted. When it is sent		delivered in the IKE_AUTH exchange, it is encrypted. When it is sent
	again in an unprotected notification, it is not, but that is the last		again in an unprotected notification, it is not, but that is the last
	time this token is ever used.		time this token is ever used.
	An aggregation of some tokens generated by one maker together with		An aggregation of some tokens generated by one maker together with
	skipping to change at page 18, line 24		skipping to change at page 17, line 50
	an existing IKE SA. This implies that a conforming QCD token maker		an existing IKE SA. This implies that a conforming QCD token maker
	MUST be able to tell whether a particular pair of IKE SPIs represent		MUST be able to tell whether a particular pair of IKE SPIs represent
	a valid IKE SA.		a valid IKE SA.
	This requirement is obvious and easy in the case of a single gateway.		This requirement is obvious and easy in the case of a single gateway.
	However, some implementations use a load balancer to divide the load		However, some implementations use a load balancer to divide the load
	between several physical gateways. It MUST NOT be possible even in		between several physical gateways. It MUST NOT be possible even in
	such a configuration to trick one gateway into sending a QCD token		such a configuration to trick one gateway into sending a QCD token
	for an IKE SA which is valid on another gateway.		for an IKE SA which is valid on another gateway.
	This document does not specify how a load sharing sharing		This document does not specify how a load sharing configuration of
	configuration of IPsec gateways would work, but in order to support		IPsec gateways would work, but in order to support this
	this specification, all members MUST be able to tell whether a		specification, all members MUST be able to tell whether a particular
	particular IKE SA is active anywhere in the cluster. One way to do		IKE SA is active anywhere in the cluster. One way to do it is to
	it is to synchronize a list of active IKE SPIs among all the cluster		synchronize a list of active IKE SPIs among all the cluster members.
	members.
	10.3. QCD Token Enumeration		10.3. QCD Token Enumeration
	An attacker may try to attack QCD if the generation algorithm		An attacker may try to attack QCD if the generation algorithm
	described in Section 5.1 is used. The attacker will send several		described in Section 5.1 is used. The attacker will send several
	fake IKE requests to the gateway under attack, receiving and		fake IKE requests to the gateway under attack, receiving and
	recording the QCD Tokens in the responses. This will allow the		recording the QCD Tokens in the responses. This will allow the
	attacker to create a dictionary of IKE SPIs to QCD Tokens, which can		attacker to create a dictionary of IKE SPIs to QCD Tokens, which can
	later be used to tear down any IKE SA.		later be used to tear down any IKE SA.
	Three factors mitigate this threat:		Three factors mitigate this threat:
	o The space of all possible IKE SPI pairs is huge: 2^128, so making		o The space of all possible IKE SPI pairs is huge: 2^128, so making
	such a dictionary is impractical. Even if we assume that one		such a dictionary is impractical. Even if we assume that one
	implementation always generates predictable IKE SPIs, the space is		implementation always generates predictable IKE SPIs, the space is
	still at least 2^64 entries, so making the dictionary is extremely		still at least 2^64 entries, so making the dictionary is extremely
	hard.		hard. To ensure this, token makers MUST use a good pseudo-random
			number generator to generate the IKE SPIs.
	o Throttling the amount of QCD_TOKEN notifications sent out, as		o Throttling the amount of QCD_TOKEN notifications sent out, as
	discussed in Section 9.1, especially when not soon after a crash		discussed in Section 9.1, especially when not soon after a crash
	will limit the attacker's ability to construct a dictionary.		will limit the attacker's ability to construct a dictionary.
	o The methods in Section 5.1 and Section 5.2 allow for a periodic		o The methods in Section 5.1 and Section 5.2 allow for a periodic
	change of the QCD_SECRET. Any such change invalidates the entire		change of the QCD_SECRET. Any such change invalidates the entire
	dictionary.		dictionary.
			10.4. Selecting an Appropriate Token Generation Method
			This section describes the rationale for token generation methods
			such as the one described in Section 5.2. Note that this section
			merely provides a possible rationale, and does not specify or
			recommend any kind of configuration.
			Some configurations of security gateway use a load-sharing cluster of
			hosts, all sharing the same IP addresses, where the SAs (IKE and
			child) are not synchronized between the cluster members. In such a
			configuration, a single member does not know about all the IKE SAs
			that are active for the configuration. A load balancer (usually a
			networking switch) sends IKE and IPsec packets to the several members
			based on source IP address.
			In such a configuration, an attacker can send a forged protected IKE
			packet with the IKE SPIs of an existing IKE SA, but from a different
			IP address. This packet will likely be processed by a different
			cluster member from the one that owns the IKE SA. Since no IKE SA
			state is stored on this member, it will send a QCD token to the
			attacker. If the QCD token does not depend on IP address, this token
			can immediately be used to tell the token taker to tear down the IKE
			SA using an unprotected QCD_TOKEN notification.
			To thwart this possible attack, such configurations should use a
			method that considers the taker's IP address, such as the method
			described in Section 5.2.
			On the other hand, when using this method a change of address
			invalidates the tokens, so this method has both advantages and
			disadvantages.
	11. IANA Considerations		11. IANA Considerations
	IANA is requested to assign a notify message type from the status		IANA is requested to assign a notify message type from the status
	types range (16406-40959) of the "IKEv2 Notify Message Types"		types range (16406-40959) of the "IKEv2 Notify Message Types"
	registry with name "QUICK_CRASH_DETECTION".		registry with name "QUICK_CRASH_DETECTION".
	12. Acknowledgements		12. Acknowledgements
	We would like to thank Hannes Tschofenig and Yaron Sheffer for their		We would like to thank Hannes Tschofenig and Yaron Sheffer for their
	comments about Session Resumption.		comments about Session Resumption.
	Frederic D'etienne and Pratima Sethi contributed the ideas in		Frederic D'etienne and Pratima Sethi contributed the ideas in
	Section 9.3 and Section 5.2.		Section 10.4 and Section 5.2.
	Others who have contrinuted valuable comments are, in alphabetical		Others who have contrinuted valuable comments are, in alphabetical
	order, Lakshminath Dondeti, Scott C Moonen and Dave Wierbowski.		order, Lakshminath Dondeti and Scott C Moonen.
	13. Change Log		13. Change Log
	This section lists all changes in this document		This section lists all changes in this document
	NOTE TO RFC EDITOR : Please remove this section in the final RFC		NOTE TO RFC EDITOR : Please remove this section in the final RFC
	13.1. Changes from draft-nir-ike-qcd-07		13.1. Changes from draft-ietf-ipsecme-failure-detection-00
			o Nits pointed out by Scott and Yaron.
			o Pratima and Frederic are back on board.
			o Changed IKEv2bis draft reference to RFC 5996.
			o Resolved issues #189, #190, #191, and #192:
			* Renamed section 4.5 and removed the requirement to send an
			acknowledgement for the unprotected message.
			* Moved the QCD token from the last to the first IKE_AUTH
			request.
			* Added a MUST to Section 10.3 to require that IKE SPIs be
			randomly generated.
			* Changed the language in Section 9.1, to not use RFC 2119
			terminology.
			* Moved the section describing why one would want the method
			dependant on IP addresses (in Section 5.2 from operational
			considerations to security considerations.
			13.2. Changes from draft-nir-ike-qcd-07
	o First WG version.		o First WG version.
	o Addressed Scott C Moonen's concern about collisions of QCD tokens.		o Addressed Scott C Moonen's concern about collisions of QCD tokens.
	o Updated references to point to IKEv2bis instead of RFC 4306 and		o Updated references to point to IKEv2bis instead of RFC 4306 and
	4718. Also converted draft reference for resumption to RFC 5723.		4718. Also converted draft reference for resumption to RFC 5723.
	o Added Dave Wiebrowski as author, and removed Pratima and Frederic.		o Added Dave Wiebrowski as author, and removed Pratima and Frederic.
	13.2. Changes from draft-nir-ike-qcd-03 and -04		13.3. Changes from draft-nir-ike-qcd-03 and -04
	Mostly editorial changes and cleaning up.		Mostly editorial changes and cleaning up.
	13.3. Changes from draft-nir-ike-qcd-02		13.4. Changes from draft-nir-ike-qcd-02
	o Described QCD token enumeration, following a question by		o Described QCD token enumeration, following a question by
	Lakshminath Dondeti.		Lakshminath Dondeti.
	o Added the ability to replace the QCD token for an existing IKE SA.		o Added the ability to replace the QCD token for an existing IKE SA.
	o Added tokens dependant on peer IP address and their interaction		o Added tokens dependent on peer IP address and their interaction
	with MOBIKE.		with MOBIKE.
	13.4. Changes from draft-nir-ike-qcd-01		13.5. Changes from draft-nir-ike-qcd-01
	o Removed stateless method.		o Removed stateless method.
	o Added discussion of rekeying and resumption.		o Added discussion of rekeying and resumption.
	o Added discussion of non-synchronized load-balanced clusters of		o Added discussion of non-synchronized load-balanced clusters of
	gateways in the security considerations.		gateways in the security considerations.
	o Other wording fixes.		o Other wording fixes.
	13.5. Changes from draft-nir-ike-qcd-00		13.6. Changes from draft-nir-ike-qcd-00
	o Merged proposal with draft-detienne-ikev2-recovery		o Merged proposal with draft-detienne-ikev2-recovery
	o Changed the protocol so that the rebooted peer generates the		o Changed the protocol so that the rebooted peer generates the
	token. This has the effect, that the need for persistent storage		token. This has the effect, that the need for persistent storage
	is eliminated.		is eliminated.
	o Added discussion of birth certificates.		o Added discussion of birth certificates.
	13.6. Changes from draft-nir-qcr-00		13.7. Changes from draft-nir-qcr-00
	o Changed name to reflect that this relates to IKE. Also changed		o Changed name to reflect that this relates to IKE. Also changed
	from quick crash recovery to quick crash detection to avoid		from quick crash recovery to quick crash detection to avoid
	confusion with IFARE.		confusion with IFARE.
	o Added more operational considerations.		o Added more operational considerations.
	o Added interaction with IFARE.		o Added interaction with IFARE.
	o Added discussion of backup gateways.		o Added discussion of backup gateways.
	14. References		14. References
	14.1. Normative References		14.1. Normative References
	[IKEv2bis]
	Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen,
	"Internet Key Exchange Protocol: IKEv2",
	draft-ietf-ipsecme-ikev2bis-11 (work in progress),
	May 2010.
	[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, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC4555] Eronen, P., "IKEv2 Mobility and Multihoming Protocol		[RFC4555] Eronen, P., "IKEv2 Mobility and Multihoming Protocol
	(MOBIKE)", RFC 4555, June 2006.		(MOBIKE)", RFC 4555, June 2006.
			[RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen,
			"Internet Key Exchange Protocol: IKEv2", RFC 5996,
			September 2010.
	14.2. Informative References		14.2. Informative References
	[RFC5723] Sheffer, Y. and H. Tschofenig, "IKEv2 Session Resumption",		[RFC5723] Sheffer, Y. and H. Tschofenig, "IKEv2 Session Resumption",
	RFC 5723, January 2010.		RFC 5723, January 2010.
	[cluster] Nir, Y., Ed., "IPsec Cluster Problem Statement",		[cluster] Nir, Y., Ed., "IPsec Cluster Problem Statement",
	draft-ietf-ipsecme-ipsec-ha (work in progress), July 2010.		draft-ietf-ipsecme-ipsec-ha (work in progress), July 2010.
	[recovery]		[recovery]
	Detienne, F., Sethi, P., and Y. Nir, "Safe IKE Recovery",		Detienne, F., Sethi, P., and Y. Nir, "Safe IKE Recovery",
	skipping to change at page 21, line 20		skipping to change at page 22, line 4
	Authors' Addresses		Authors' Addresses
	Yoav Nir (editor)		Yoav Nir (editor)
	Check Point Software Technologies Ltd.		Check Point Software Technologies Ltd.
	5 Hasolelim st.		5 Hasolelim st.
	Tel Aviv 67897		Tel Aviv 67897
	Israel		Israel
	Email: ynir@checkpoint.com		Email: ynir@checkpoint.com
	David Wierbowski		David Wierbowski
	International Business Machines		International Business Machines
	1701 North Street		1701 North Street
	Endicott, New York 13760		Endicott, New York 13760
	United States		United States
	Email: wierbows@us.ibm.com		Email: wierbows@us.ibm.com
			Frederic Detienne
			Cisco Systems, Inc.
			De Kleetlaan, 7
			Diegem B-1831
			Belgium
			Phone: +32 2 704 5681
			Email: fd@cisco.com
			Pratima Sethi
			Cisco Systems, Inc.
			O'Shaugnessy Road, 11
			Bangalore, Karnataka 560027
			India
			Phone: +91 80 4154 1654
			Email: psethi@cisco.com
End of changes. 50 change blocks.
	99 lines changed or deleted		126 lines changed or added
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