< draft-ietf-dhc-dhcpv6-agentopt-delegate-01.txt		draft-ietf-dhc-dhcpv6-agentopt-delegate-02.txt >
	dhc Group R. Droms		dhc Group R. Droms
	Internet-Draft B. Volz		Internet-Draft B. Volz
	Intended status: Informational O. Troan		Intended status: Informational O. Troan
	Expires: February 11, 2007 Cisco Systems, Inc.		Expires: May 31, 2007 Cisco Systems, Inc.
	August 10, 2006		November 27, 2006
	DHCPv6 Relay Agent Assignment Notification (RAAN) Option		DHCPv6 Relay Agent Assignment Notification (RAAN) Option
	draft-ietf-dhc-dhcpv6-agentopt-delegate-01.txt		draft-ietf-dhc-dhcpv6-agentopt-delegate-02.txt
	Status of this Memo		Status of this Memo
	By submitting this Internet-Draft, each author represents that any		By submitting this Internet-Draft, each author represents that any
	applicable patent or other IPR claims of which he or she is aware		applicable patent or other IPR claims of which he or she is aware
	have been or will be disclosed, and any of which he or she becomes		have been or will be disclosed, and any of which he or she becomes
	aware will be disclosed, in accordance with Section 6 of BCP 79.		aware will be disclosed, in accordance with Section 6 of BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF), its areas, and its working groups. Note that		Task Force (IETF), its areas, and its working groups. Note that
	skipping to change at page 1, line 35 ¶		skipping to change at page 1, line 35 ¶
	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 February 11, 2007.		This Internet-Draft will expire on May 31, 2007.
	Copyright Notice		Copyright Notice
	Copyright (C) The Internet Society (2006).		Copyright (C) The Internet Society (2006).
	Abstract		Abstract
	The DHCP Relay Agent Assignment Notification (RAAN) option is sent		The DHCP Relay Agent Assignment Notification (RAAN) option is sent
	from a DHCP server to a DHCP relay agent to inform the relay agent of		from a DHCP server to a DHCP relay agent to inform the relay agent of
	IPv6 addresses that have been assigned or IPv6 prefixes that have		IPv6 addresses that have been assigned or IPv6 prefixes that have
	skipping to change at page 2, line 18 ¶		skipping to change at page 2, line 18 ¶
	encapsulates address and prefix options to indicate that an address		encapsulates address and prefix options to indicate that an address
	or prefix has been assigned. The option may also carry other		or prefix has been assigned. The option may also carry other
	information required by the network element for configuration related		information required by the network element for configuration related
	to the assigned address or prefix.		to the assigned address or prefix.
	For example, a network administrator uses the RAAN option to inform a		For example, a network administrator uses the RAAN option to inform a
	relay agent of a prefix that has been delegated through DHCP PD to a		relay agent of a prefix that has been delegated through DHCP PD to a
	DHCP client. The relay agent notifies the network element on which		DHCP client. The relay agent notifies the network element on which
	it is implemented of the delegation information so the network		it is implemented of the delegation information so the network
	element can add routing information about the delegated prefix into		element can add routing information about the delegated prefix into
	the appropriate routing protocols.		the routing infrastructure.
	2. Terminology		2. Terminology
	The key words MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,		The key words MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
	SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this document are to be		SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this document are to be
	interpreted as described in RFC 2119 [1].		interpreted as described in RFC 2119 [1].
	The term "DHCP" in this document refers to DHCP for IPv6, as defined		The term "DHCP" in this document refers to DHCP for IPv6, as defined
	in RFC 3315 [2]. The terms "DHCP prefix delegation" and "DHCP PD"		in RFC 3315 [2]. The terms "DHCP prefix delegation" and "DHCP PD"
	refer DHCP for IPv6 prefix delegation, as defined in RFC 3633 [3]		refer DHCP for IPv6 prefix delegation, as defined in RFC 3633 [3]
	Additional terms used in the description of DHCP and DHCP prefix		Additional terms used in the description of DHCP and DHCP prefix
	delegation are defined in RFC 3315 and RFC 3633. In this document		delegation are defined in RFC 3315 and RFC 3633. In this document
	"assigning" an IPv6 prefix is equivalent to "delegating" a prefix.		"assigning" an IPv6 prefix is equivalent to "delegating" a prefix.
	3. Option semantics		3. Option Semantics and Usage
	The RAANn option carries information about assigned IPv6 addresses		The RAAN option carries information about assigned IPv6 addresses and
	and prefixes. It encapsulates an IA Address option (RFC 3315) or an		prefixes. It encapsulates IA Address options (RFC 3315) and/or IA
	IA Prefix option (RFC 3633), and possibly other options that carry		Prefix options (RFC 3633), and possibly other options that carry
	other information related to the assigned IPv6 address or prefix.		other information related to the assigned IPv6 address or prefix.
	The DHCP server MAY include this option in a Reply message sent to a
	client that includes assigned addresses and/or prefixes. If the DHCP
	server does include this option in a Reply message, it MUST include
	it in the option area of the Relay-reply message sent to the relay
	agent intended as the recipient of the option.
	The DHCP server is responsible for synchronizing any state created by		The DHCP server is responsible for synchronizing any state created by
	a node through the use of the RAAN option. For example, if a DHCP		a node through the use of the RAAN option. For example, if a DHCP
	server receives a Release message for a delegated prefix, it causes		server receives a Release message for a delegated prefix, it causes
	the node to delete any state associated with that prefix by sending		the node to delete any state associated with that prefix by sending a
	an RAAN option containing an IA Prefix option with the released		RAAN option containing an IA Prefix option with the released prefix
	prefix and a valid lifetime of zero.		and a valid lifetime of zero.
	A relay agent that receives this option SHOULD pass the information
	to the node in which the relay agent is instantiated. The node MAY
	make use of the information received from the relay agent.
	If a node creates state based on the information included in this		When a DHCP server sends this option to a relay agent, it MUST
	option, it MUST remove that state when the lifetime as specified in		include all addresses and prefixes assigned to the client on the link
	the option expires.		to which the option refers at the time the option is sent.
	Examples of use:		Examples of use:
	o Populate an ACL with an assigned IPv6 address if the network		o Populate an ACL with an assigned IPv6 address if the network
	device in which the relay agent is instantiated implements a		security policy requires limiting IPv6 forwarding to devices that
	security policy limiting IPv6 forwarding to devices that have		have obtained an address through DHCP
	obtained an address through DHCP
	o Inject routing information into a routing infrastructure about a		o Inject routing information into a routing infrastructure about a
	delegated prefix on behalf of a requesting router		delegated prefix on behalf of a requesting router
	4. Option format		4. Relay Agent Behavior
			A relay agent that wants information from the server in a RAAN option
			includes an ORO requesting the RAAN option in its Relay-Forw message.
			A relay agent may do this for any relayed message, regardless of the
			message type or the message contents.
			When a relay agent receives a Relay-Reply message containing a RAAN
			option, the relay agent may forward that option data to the node in
			which the relay agent is instantiated. If no RAAN option is included
			in the Relay-Reply, the relay agent MUST NOT assume anything with
			regard to RAAN data and MUST NOT forward any indication to the node
			in which the relay agent is instantiated.
			If a node creates state based on the information included in this
			option, it MUST remove that state when the lifetime as specified in
			the option expires.
			5. Server Behavior
			When a server is responding to a request and the ORO contains an RAAN
			option, the server SHOULD include a RAAN option with all of the
			addresses and prefixes that have been (or are being assigned) to the
			client. If no addresses or prefixes are assigned, the server SHOULD
			send a RAAN option with no addresses or prefixes.
			If the DHCP server does include this option in a Relay-Reply message,
			it MUST include it in the option area of the Relay-Reply message sent
			to the relay agent intended as the recipient of the option.
			If the message received from the client contains no Client Identifier
			option or the server is otherwise unable to identify the client or
			the client's link (perhaps because of missing or invalid data in the
			request), the server MUST NOT include a RAAN option in the response.
			6. Option format
	The RAAN option has the following format:		The RAAN option has the following format:
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| option-code | length |		| option-code | length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| encapsulated-options |		| encapsulated-options |
	. .		. .
	. .		. .
	. .		. .
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	option-code OPTION_AGENT_NOTIFY (TBD)		option-code OPTION_AGENT_NOTIFY (TBD)
	length length of encapsulated options, in octets		length length of encapsulated options, in octets
	encapsulated-options DHCP options to be delivered by the Relay Agent		encapsulated-options DHCP options to be delivered by the relay agent
	Assignment Notification option		Assignment Notification option
	5. Encapsulating DHCP options in the RAAN Option		7. Encapsulating DHCP options in the RAAN Option
	The contents of options encapsulated in the RAAN option are		The contents of options encapsulated in the RAAN option are
	interpreted according to the use of those options in the node on		interpreted according to the use of those options in the node on
	which the relay agent is implemented. For the purposes of address		which the relay agent is implemented. For the purposes of address
	and prefix assignment, the uses of the DHCP IA Address and IA Prefix		and prefix assignment, the uses of the DHCP IA Address and IA Prefix
	options are defined in this document.		options are defined in this document.
	Note that the contents of these options are not necessarily the same		Note that the contents of these options are not necessarily the same
	as in the corresponding options sent to the DHCP client. For		as in the corresponding options sent to the DHCP client.
	example, the node that receives the information from these options
	may be instructed to use the information for a shorter period of time
	than the client by setting a shorter valid-lifetime in the this
	option.
	5.1. IA Address option		7.1. IA Address option
	The fields in an IA Address option (OPTION_IAADDR, option code 5) are		The fields in an IA Address option (OPTION_IAADDR, option code 5) are
	used as follows:		used as follows:
	IPv6 address The IPv6 address assigned in this DHCP message		IPv6 address The IPv6 address assigned in this DHCP message
	preferred-lifetime Not used at the time this document was published		preferred-lifetime Not used by the relay agent; the server SHOULD
			set this field to the preferred-lifetime of the
			corresponding IA Address options in the message
			to be forwarded to the client
	valid-lifetime The expiration lifetime of the information carried in		valid-lifetime The lifetime of the information carried in this
	this IA Address option, expressed in units of seconds; the		IA Address option, expressed in units of seconds;
	expiration-lifetime is a relative time, giving the duration		if the valid-lifetime is 0, the information is no
	relative to the current time of the information in this IA Address		longer valid
	option; if the valid-lifetime is 0, the information is no longer
	valid.
	IAaddr-options Not used		IAaddr-options Not used by the relay agent; the server SHOULD
			set this field to the IAaddr-options of the
			corresponding IA Address option in the message to
			be forwarded to the client
	5.2. IA Prefix option		7.2. IA Prefix option
	The fields in an IA Prefix option (OPTION_IAPREFIX, option code 28)		The fields in an IA Prefix option (OPTION_IAPREFIX, option code 28)
	are used as follows:		are used as follows:
	preferred-lifetime Not used		preferred-lifetime Not used by the relay agent; the server SHOULD
			set this field to the preferred-lifetime of the
			corresponding IA Prefix options in the message to
			be forwarded to the client
	valid-lifetime The expiration lifetime of the information carried in		valid-lifetime The lifetime of the information carried in this
	this IA Prefix option, expressed in units of seconds; the		IA Prefix option, expressed in units of seconds;
	expiration-lifetime is a relative time, giving the duration		if the valid-lifetime is 0, the information is no
	relative to the current time of the information in this IA Prefix		longer valid
	option; if the valid-lifetime is 0, the information is no longer
	valid.
	prefix-length length for this prefix in bits		prefix-length length for this prefix in bits
	IPv6-prefix The IPv6 prefix assigned in this DHCP message
	IAprefix-options Not used at the time this document was published		IPv6-prefix The IPv6 prefix assigned in this DHCP message
	6. Requesting assignment information from the DHCP server		IAprefix-options Not used by the relay agent; the server SHOULD
			set this field to the IAprefix-options of the
			corresponding IA Prefix option in the message to
			be forwarded to the client
			8. Requesting assignment information from the DHCP server
	If a relay agent requires the DHCP server to provide information		If a relay agent requires the DHCP server to provide information
	about assigned addresses and prefixes, it MUST include an Option		about assigned addresses and prefixes, it MUST include an Option
	Request option, requesting the Assignment Notification option, as		Request option, requesting the Assignment Notification option, as
	described in section 22.7 of RFC 3315.		described in section 22.7 of RFC 3315.
	7. Reordering received DHCP messages		9. Reordering received DHCP messages
	The relay agent MUST use the Server Reply Sequence Number (SRSN)		The relay agent MUST use the Server Reply Sequence Number (SRSN)
	option [4] to detect and discard RAAN options contained in DHCP		option [4] to detect and discard RAAN options contained in DHCP
	messages that are received out of order.		messages that are received out of order.
	8. IANA considerations		10. IANA considerations
	IANA is requested to assign an option code from the "DHCPv6 and		IANA is requested to assign an option code from the "DHCPv6 and
	DHCPv6 options" registry		DHCPv6 options" registry
	http://www.iana.org/assignments/dhcpv6-parameters to		http://www.iana.org/assignments/dhcpv6-parameters to
	OPTION_AGENT_NOTIFY.		OPTION_AGENT_NOTIFY.
	9. Security considerations		11. Security considerations
	Security issues related to DHCP are described in RFC 3315 and RFC		Security issues related to DHCP are described in RFC 3315 and RFC
	3633.		3633.
	The RAAN option may be used to mount a denial of service attack by		The RAAN option may be used to mount a denial of service attack by
	causing a node to incorrectly populate an ACL or incorrectly		causing a node to incorrectly populate an ACL or incorrectly
	configure routing protocol information for a delegated prefix. This		configure routing information for a delegated prefix. This option
	option may also be used to insert invalid prefixes into the routing		may also be used to insert invalid prefixes into the routing
	infrastruture or add invalid IP addresses to ACLs in nodes.		infrastructure or add invalid IP addresses to ACLs in nodes.
	Communication between a server and a relay agent, and communication		Communication between a server and a relay agent, and communication
	between relay agents, can be secured through the use of IPSec, as		between relay agents, can be secured through the use of IPSec, as
	described in section 21.1 of RFC 3315.		described in section 21.1 of RFC 3315.
	10. Changes in this revision		12. Changes log
	If this section is included in the document when it is submitted for		If this section is included in the document when it is submitted for
	publication, the RFC Editor is requested to remove it.		publication, the RFC Editor is requested to remove it.
	Changes in rev -01:		Changes in rev -01:
	o Added section describing use of "Server Reply Sequence Number"		o Added section describing use of "Server Reply Sequence Number"
	option to allow resequencing of out-of-order messages		option to allow resequencing of out-of-order messages
	11. Normative References		Changes in rev -02:
			o Made editorial change in section 1: s/the appropriate routing
			protocols/the routing infrastructure/
			o Updated first paragraph in Section 3 to allow multiple IA Address
			options and/or IA Prefix options
			o Renamed section "Options Semantics and Usage"
			o Added paragraph to section "Option Semantics and Usage" requiring
			that the DHCP server must include all addresses/prefixes for the
			client (on that link) in the RAAN option
			o Added list of use cases to section "Option Semantics and Usage"
			o Added section "Relay Agent Behavior"
			o Added section "Server Behavior"; moved second paragraph of section
			"Option Semantics and Usage" to "Server Behavior"
			o Updated reference to draft-ietf-dhc-dhcpv6-srsn-option-00
			o Clarified descriptions of various option fields in section
			"Encapsulating DHCP options in the RAAN Option"
			13. Normative References
	[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement		[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
	Levels", BCP 14, RFC 2119, March 1997.		Levels", BCP 14, RFC 2119, March 1997.
	[2] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M.		[2] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M.
	Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",		Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
	RFC 3315, July 2003.		RFC 3315, July 2003.
	[3] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host		[3] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host
	Configuration Protocol (DHCP) version 6", RFC 3633,		Configuration Protocol (DHCP) version 6", RFC 3633,
	December 2003.		December 2003.
	[4] Volz, B. and R. Droms, "DHCPv6 Server Reply Sequence Number		[4] Volz, B. and R. Droms, "DHCPv6 Server Reply Sequence Number
	Option", draft-volz-dhc-dhcpv6-srsn-option-00 (work in		Option", draft-ietf-dhc-dhcpv6-srsn-option-00 (work in
	progress), August 2006.		progress), November 2006.
	Authors' Addresses		Authors' Addresses
	Ralph Droms		Ralph Droms
	Cisco Systems, Inc.		Cisco Systems, Inc.
	1414 Massachusetts Avenue		1414 Massachusetts Avenue
	Boxborough, MA 01719		Boxborough, MA 01719
	USA		USA
	Phone: +1 978.936.1674		Phone: +1 978.936.1674
End of changes. 32 change blocks.
	68 lines changed or deleted		114 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/