draft-ietf-v6ops-addr-select-ps-05.txt		draft-ietf-v6ops-addr-select-ps-06.txt
	IPv6 Operations Working Group A. Matsumoto		IPv6 Operations Working Group A. Matsumoto
	Internet-Draft T. Fujisaki		Internet-Draft T. Fujisaki
	Intended status: Informational NTT		Intended status: Informational NTT
	Expires: October 24, 2008 R. Hiromi		Expires: November 15, 2008 R. Hiromi
	K. Kanayama		K. Kanayama
	Intec Netcore		Intec Netcore
	April 22, 2008		May 14, 2008
	Problem Statement of Default Address Selection in Multi-prefix		Problem Statement of Default Address Selection in Multi-prefix
	Environment: Operational Issues of RFC3484 Default Rules		Environment: Operational Issues of RFC3484 Default Rules
	draft-ietf-v6ops-addr-select-ps-05.txt		draft-ietf-v6ops-addr-select-ps-06.txt
	Status of this Memo		Status of this Memo
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	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
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	skipping to change at page 1, line 38		skipping to change at page 1, line 38
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	This Internet-Draft will expire on October 24, 2008.		This Internet-Draft will expire on November 15, 2008.
	Copyright Notice		Copyright Notice
	Copyright (C) The IETF Trust (2008).		Copyright (C) The IETF Trust (2008).
	Abstract		Abstract
	One physical link can carry multiple subnets. Moreover, we can use		A single physical link can have multiple prefixes assigned to it. In
	multiple physical networks at the same time in a host. In that		that environment, end hosts might have multiple IP addresses and be
	environment, end hosts might have multiple IP addresses and be		required to use them selectively. RFC 3484 defines default source
	required to use them selectively. Without an appropriate source/		and destination address selection rules and is implemented in a
	destination address selection mechanism, the host will experience		variety of OS's. But, it has been too difficult to use operationally
	some trouble in communication. RFC 3484 defines default source and		for several reasons, In some environment where multiple prefixes are
	destination address selection algorithms, but the multi-prefix		assigned on a single physical link, the host with the default address
	environment considered here needs additional rules beyond those of		selection rules will experience some trouble in communication. This
	the default operation. This document describes the possible problems		document describes the possible problems that end hosts could
	that end hosts could encounter in an environment with multiple		encounter in an environment with multiple prefixes.
	subnets.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
	1.1. Scope of this document . . . . . . . . . . . . . . . . . . 3		1.1. Scope of this document . . . . . . . . . . . . . . . . . . 3
	2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3		2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 4
	2.1. Source Address Selection . . . . . . . . . . . . . . . . . 3		2.1. Source Address Selection . . . . . . . . . . . . . . . . . 4
	2.1.1. Multiple Routers on Single Interface . . . . . . . . . 4		2.1.1. Multiple Routers on Single Interface . . . . . . . . . 4
	2.1.2. Ingress Filtering Problem . . . . . . . . . . . . . . 5		2.1.2. Ingress Filtering Problem . . . . . . . . . . . . . . 5
	2.1.3. Half-Closed Network Problem . . . . . . . . . . . . . 5		2.1.3. Half-Closed Network Problem . . . . . . . . . . . . . 6
	2.1.4. Combined Use of Global and ULA . . . . . . . . . . . . 7		2.1.4. Combined Use of Global and ULA . . . . . . . . . . . . 7
	2.1.5. Site Renumbering . . . . . . . . . . . . . . . . . . . 8		2.1.5. Site Renumbering . . . . . . . . . . . . . . . . . . . 8
	2.1.6. Multicast Source Address Selection . . . . . . . . . . 8		2.1.6. Multicast Source Address Selection . . . . . . . . . . 9
	2.1.7. Temporary Address Selection . . . . . . . . . . . . . 9		2.1.7. Temporary Address Selection . . . . . . . . . . . . . 9
	2.2. Destination Address Selection . . . . . . . . . . . . . . 9		2.2. Destination Address Selection . . . . . . . . . . . . . . 10
	2.2.1. IPv4 or IPv6 prioritization . . . . . . . . . . . . . 9		2.2.1. IPv4 or IPv6 prioritization . . . . . . . . . . . . . 10
	2.2.2. ULA and IPv4 dual-stack environment . . . . . . . . . 10		2.2.2. ULA and IPv4 dual-stack environment . . . . . . . . . 11
	2.2.3. ULA or Global Prioritization . . . . . . . . . . . . . 11		2.2.3. ULA or Global Prioritization . . . . . . . . . . . . . 12
	3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 12		3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 13
	4. Security Considerations . . . . . . . . . . . . . . . . . . . 12		4. Security Considerations . . . . . . . . . . . . . . . . . . . 13
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13		6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
	6.1. Normative References . . . . . . . . . . . . . . . . . . . 13		6.1. Normative References . . . . . . . . . . . . . . . . . . . 14
	6.2. Informative References . . . . . . . . . . . . . . . . . . 14		6.2. Informative References . . . . . . . . . . . . . . . . . . 14
	Appendix A. Appendix. Revision History . . . . . . . . . . . . . 14		Appendix A. Appendix. Revision History . . . . . . . . . . . . . 14
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
	Intellectual Property and Copyright Statements . . . . . . . . . . 16		Intellectual Property and Copyright Statements . . . . . . . . . . 17
	1. Introduction		1. Introduction
	One physical link can carry multiple subnets. In that case, an end-		In IPv6, a single physical link can have multiple prefixes assigned
	host has multiple IP addresses. In the IPv4-IPv6 dual stack		to it. In such cases, an end-host may have multiple IP addresses
	environment or in a site connected to both a ULA [RFC4193] and Global		assigned to an interface on that link. In the IPv4-IPv6 dual stack
	scope networks, an end-host has multiple IP addresses. These are		environment or in a site connected to both a ULA [RFC4193] and
	examples of networks that we focus on in this document. In such an		Globally routable networks, an end-host typically has multiple IP
	environment, an end-host will encounter some communication troubles.		addresses. These are examples of the networks that we focus on in
			this document. In such an environment, an end-host may encounter
			some communication troubles.
	Inappropriate source address selection at the end-host causes		Inappropriate source address selection at the end-host causes
	unexpected asymmetric routing, filtering by a router or discarding of		unexpected asymmetric routing, filtering by a router or discarding of
	packets bacause there is no route to the host.		packets bacause there is no route to the host.
	Considering a multi-prefix environment, destination address selection		Considering a multi-prefix environment, destination address selection
	is also important for correct or better communication establishment.		is also important for correct or better communication establishment.
	RFC 3484 [RFC3484] defines default source and destination address		RFC 3484 [RFC3484] defines default source and destination address
	selection algorithms. In most cases, the host will be able to		selection algorithms and is implemented in a variety of OS's. But,
	communicate with the targeted host using the algorithms. However,		it has been too difficult to use operationally for several reasons,
	there are still problematic cases. This document describes such		such as lack of autoconfiguration method. There are some problematic
	possibilities of incorrect address selection, which leads to dropping		cases where the host with the default address selection rules
	packets and communication failure.		encounter communication troubles.
			This document describes such possibilities of incorrect address
			selection which leads to dropping packets and communication failure.
	1.1. Scope of this document		1.1. Scope of this document
	There has been a lot of discussion about "multiple addresses/		As other mechanisms already exists, the multi-homing techniques for
	prefixes". As other mechanisms already exists, the multi-homing		achieving redundancy are basically out of our scope.
	techniques for achieving redundancy are out of our scope.
	We focus on an end-site network environment. The scope of this		We focus on an end-site network environment and unmanaged hosts in
	document is to sort out problematic cases related to address		such an environment. This is because address selection behavior at
	selection. It includes problems that cannot always be solved by		this kind of hosts are difficult to manipulate owing to the users's
	changing the host's address selection algorithm, such as an address		lack of knowledge, hosts' location, or massiveness of the hosts.
	selection mechanism that depends on the IPv6 address types. For
	example, a global address isn't always globally routable and ULA's		The scope of this document is to sort out problematic cases related
	routable domain is dependent on the network policy. This document		to address selection. It includes problems that can be solved in the
	includes these kind of network policy related address selection		framework of RFC 3484 and problems that cannot. For the latter, RFC
	problems, as long as these problems are serious enough and worth		3484 might be modified to meet their needs, or another address
	solving.		selection solution might be necessary. For the former, an additional
			mechanism that mitigates the operational difficulty might be
			necessary.
			This document also includes simple solution analysis for each
			problematic case. This analysis basically just focuses on whether
			the case can be solved in the framework of RFC 3484 or not. If not,
			some possible solutions are described. Even if a case can be solved
			in the framework of RFC 3484, as mentioned above, it does not
			necessarily mean that there is no operational difficulty. For
			example, in the environment stated above, it is not a feasible
			solution to configure each host's policy table by hand. So, for such
			an solution, configuration pain is yet another common problem.
	2. Problem Statement		2. Problem Statement
	2.1. Source Address Selection		2.1. Source Address Selection
	2.1.1. Multiple Routers on Single Interface		2.1.1. Multiple Routers on Single Interface
	==================		==================
	| Internet |		| Internet |
	==================		==================
	skipping to change at page 4, line 33		skipping to change at page 4, line 44
	-----+-+-----+------		-----+-+-----+------
	|		|
	+-+----+ 2001:db8:1000:1::100		+-+----+ 2001:db8:1000:1::100
	| Host | 2001:db8:8000:1::100		| Host | 2001:db8:8000:1::100
	+------+		+------+
	[Fig. 1]		[Fig. 1]
	Generally speaking, there is no interaction between next-hop		Generally speaking, there is no interaction between next-hop
	determination and address selection. In this example, when a host		determination and address selection. In this example, when a host
	sends a packet via Router1, the host does not necessarily choose		starts a new connection and sends a packet via Router1, the host does
	address 2001:db8:1000:1::100 given by Router1 as the source address.		not necessarily choose address 2001:db8:1000:1::100 given by Router1
	This causes the same problem as described in the next section		as the source address. This causes the same problem as described in
	'Ingress Filtering Problem'.		the next section 'Ingress Filtering Problem'.
			Solution analysis:
			As this case depends on next hop selection, controling the address
			selection behavior at Host alone doesn't solve the entire problem.
			One possible solution for this case is adopting source address
			based routing at Router1 and Router2. Another solution may be
			using static routing at Router1, Router2 and Host, and using the
			corresponding static address selection policy at Host.
	2.1.2. Ingress Filtering Problem		2.1.2. Ingress Filtering Problem
	==================		==================
	| Internet |		| Internet |
	==================		==================
	| |		| |
	2001:db8:1000::/36 | | 2001:db8:8000::/36		2001:db8:1000::/36 | | 2001:db8:8000::/36
	+----+-+ +-+----+		+----+-+ +-+----+
	| ISP1 | | ISP2 |		| ISP1 | | ISP2 |
	skipping to change at page 5, line 45		skipping to change at page 5, line 52
	delegated by an upstream ISP, there is a possibility that the packet		delegated by an upstream ISP, there is a possibility that the packet
	will be dropped at the ISP by its Ingress Filter. Ingress		will be dropped at the ISP by its Ingress Filter. Ingress
	filtering(uRPF: unicast Reverse Path Forwarding) is becoming more		filtering(uRPF: unicast Reverse Path Forwarding) is becoming more
	popular among ISPs to mitigate the damage of DoS attacks.		popular among ISPs to mitigate the damage of DoS attacks.
	In this example, when the Router chooses the default route to ISP2		In this example, when the Router chooses the default route to ISP2
	and the Host chooses 2001:db8:1000:1::100 as the source address for		and the Host chooses 2001:db8:1000:1::100 as the source address for
	packets sent to a host (2001:db8:2000::1) somewhere on the Internet,		packets sent to a host (2001:db8:2000::1) somewhere on the Internet,
	the packets may be dropped at ISP2 because of Ingress Filtering.		the packets may be dropped at ISP2 because of Ingress Filtering.
			Solution analysis:
			One possible solution for this case is adopting source address
			based routing at Router. Another solution may be using static
			routing at Router, and using the corresponding static address
			selection policy at Host.
	2.1.3. Half-Closed Network Problem		2.1.3. Half-Closed Network Problem
	You can see a second typical source address selection problem in a		You can see a second typical source address selection problem in a
	multihome site with global-closed mixed connectivity like in the		multihome site with global-closed mixed connectivity like in the
	figure below. In this case, Host-A is in a multihomed network and		figure below. In this case, Host-A is in a multihomed network and
	has two IPv6 addresses, one delegated from each of the upstream ISPs.		has two IPv6 addresses, one delegated from each of the upstream ISPs.
	Note that ISP2 is a closed network and does not have connectivity to		Note that ISP2 is a closed network and does not have connectivity to
	the Internet.		the Internet.
	+--------+		+--------+
	skipping to change at page 7, line 7		skipping to change at page 7, line 21
	filtered by ISP1, a return packet from Host-C cannot possibly be		filtered by ISP1, a return packet from Host-C cannot possibly be
	delivered to Host-A because the return packet is destined for 2001:		delivered to Host-A because the return packet is destined for 2001:
	db8:8000:1::100, which is closed from the Internet.		db8:8000:1::100, which is closed from the Internet.
	The important point is that each host chooses a correct source		The important point is that each host chooses a correct source
	address for a given destination address. To solve this kind of		address for a given destination address. To solve this kind of
	network policy based address selection problems, it is likely that		network policy based address selection problems, it is likely that
	delivering addtional information to a node fits better than		delivering addtional information to a node fits better than
	algorithmic solutions that are local to the node.		algorithmic solutions that are local to the node.
			Solution analysis:
			This problem can be solved in the RFC 3484 framework. For
			example, configuring some address selection policies into Host-A's
			RFC 3484 policy table can solve this problem.
	2.1.4. Combined Use of Global and ULA		2.1.4. Combined Use of Global and ULA
	============		============
	| Internet |		| Internet |
	============		============
	|		|
	|		|
	+----+----+		+----+----+
	| ISP |		| ISP |
	+----+----+		+----+----+
	skipping to change at page 7, line 32		skipping to change at page 8, line 4
	| | 2001:db8:a:100::/64		| | 2001:db8:a:100::/64
	fd01:2:3:200:/64 | | fd01:2:3:100:/64		fd01:2:3:200:/64 | | fd01:2:3:100:/64
	-----+--+- -+--+----		-----+--+- -+--+----
	| |		| |
	fd01:2:3:200::101 | | 2001:db8:a:100::100		fd01:2:3:200::101 | | 2001:db8:a:100::100
	+----+----+ +-+----+ fd01:2:3:100::100		+----+----+ +-+----+ fd01:2:3:100::100
	| Printer | | Host |		| Printer | | Host |
	+---------+ +------+		+---------+ +------+
	[Fig. 4]		[Fig. 4]
			As RFC 4864 [RFC4864] describes, using a ULA may be beneficial in
	As NAP [I-D.ietf-v6ops-nap] describes, using a ULA may be beneficial		some scenarios. If the ULA is used for internal communication,
	in some scenarios. If the ULA is used for internal communication,
	packets with ULA need to be filtered at the Router.		packets with ULA need to be filtered at the Router.
	This case does not presently create an address selection problem		This case does not presently create an address selection problem
	because of the dissimilarity between the ULA and the Global Unicast		because of the dissimilarity between the ULA and the Global Unicast
	Address. The longest matching rule of RFC 3484 chooses the correct		Address. The longest matching rule of RFC 3484 chooses the correct
	address for both intra-site and extra-site communication.		address for both intra-site and extra-site communication.
	In the future, however, there is a possibility that the longest		In the future, however, there is a possibility that the longest
	matching rule will not be able to choose the correct address anymore.		matching rule will not be able to choose the correct address anymore.
	That is the moment when the assignment of those Global Unicast		That is the moment when the assignment of those Global Unicast
	skipping to change at page 8, line 11		skipping to change at page 8, line 30
	Namely, when we start to assign a part of the address block 8000::/1		Namely, when we start to assign a part of the address block 8000::/1
	as the global unicast address and that part is used somewhere in the		as the global unicast address and that part is used somewhere in the
	Internet, the longest matching rule ceases to function properly for		Internet, the longest matching rule ceases to function properly for
	the people trying to connect to the servers with those addresses.		the people trying to connect to the servers with those addresses.
	For example, when the destination host has an IPv6 address 8000::1,		For example, when the destination host has an IPv6 address 8000::1,
	and the originating host has 2001:db8::1 and fd0:1::1, the source		and the originating host has 2001:db8::1 and fd0:1::1, the source
	address will be fd00:1::1, because the longest matching bit length is		address will be fd00:1::1, because the longest matching bit length is
	0 for 2001:db8::1 and 1 for fd0:1::1 respectively.		0 for 2001:db8::1 and 1 for fd0:1::1 respectively.
			Solution analysis:
			This problem can be solved in the RFC 3484 framework. For
			example, configuring some address selection policies into Host's
			RFC 3484 policy table can solve this problem. Another solution is
			to modify RFC 3484 and define ULA's scope smaller than the global
			scope.
	2.1.5. Site Renumbering		2.1.5. Site Renumbering
	RFC 4192 [RFC4192] describes a recommended procedure for renumbering		RFC 4192 [RFC4192] describes a recommended procedure for renumbering
	a network from one prefix to another. An autoconfigured address has		a network from one prefix to another. An autoconfigured address has
	a lifetime, so by stopping advertisement of the old prefix, the		a lifetime, so by stopping advertisement of the old prefix, the
	autoconfigured address is eventually invalidated.		autoconfigured address is eventually invalidated.
	However, invalidating the old prefix takes a long time. You cannot		However, invalidating the old prefix takes a long time. You cannot
	stop routing to the old prefix as long as the old prefix is not		stop routing to the old prefix as long as the old prefix is not
	removed from the host. This can be a tough issue for ISP network		removed from the host. This can be a tough issue for ISP network
	skipping to change at page 8, line 42		skipping to change at page 9, line 20
	| 2001:db8:b::/64 (new)		| 2001:db8:b::/64 (new)
	| 2001:db8:a::/64 (old)		| 2001:db8:a::/64 (old)
	------+---+----------		------+---+----------
	|		|
	+--+-----+ 2001:db8:b::100 (new)		+--+-----+ 2001:db8:b::100 (new)
	| Host-A | 2001:db8:a::100 (old)		| Host-A | 2001:db8:a::100 (old)
	+--------+		+--------+
	[Fig. 5]		[Fig. 5]
			Solution analysis:
			This problem can be mitigated in the RFC 3484 framework. For
			example, configuring some address selection policies into the
			Host-A's RFC 3484 policy table can solve this problem.
	2.1.6. Multicast Source Address Selection		2.1.6. Multicast Source Address Selection
	This case is an example of site-local or global prioritization. When		This case is an example of site-local or global prioritization. When
	you send a multicast packet across site-borders, the source address		you send a multicast packet across site-borders, the source address
	of the multicast packet should be a globally routable address. The		of the multicast packet should be a globally routable address. The
	longest matching algorithm, however, selects a ULA if the sending		longest matching algorithm, however, selects a ULA if the sending
	host has both a ULA and a Global Unicast Address.		host has both a ULA and a Global Unicast Address.
	2.1.7. Temporary Address Selection		2.1.7. Temporary Address Selection
	skipping to change at page 9, line 23		skipping to change at page 9, line 51
	If you could turn the temporary address on and off, that would be		If you could turn the temporary address on and off, that would be
	better. If you could switch its usage per service (destination		better. If you could switch its usage per service (destination
	address), that would also be better. The same situation can be found		address), that would also be better. The same situation can be found
	when using HA (home address) and CoA (care-of address)in a Mobile		when using HA (home address) and CoA (care-of address)in a Mobile
	IPv6 [RFC3775] network.		IPv6 [RFC3775] network.
	At the Future Work section in RFC 3041, it discusses that the API		At the Future Work section in RFC 3041, it discusses that the API
	extension might be necessary to achieve better address selection		extension might be necessary to achieve better address selection
	mechanism with finer granularity.		mechanism with finer granularity.
			Solution analysis:
			This problem can not be solved in the RFC 3484 framework. A
			possible solution is to make applications to select desirable
			addresses by using IPv6 Socket API for Source Address Selection
			defind in RFC 5014 [RFC5014].
	2.2. Destination Address Selection		2.2. Destination Address Selection
	2.2.1. IPv4 or IPv6 prioritization		2.2.1. IPv4 or IPv6 prioritization
	The default policy table gives IPv6 addresses higher precedence than		The default policy table gives IPv6 addresses higher precedence than
	IPv4 addresses. There seem to be many cases, however, where network		IPv4 addresses. There seem to be many cases, however, where network
	administrators want to control the address selection policy of end-		administrators want to control the address selection policy of end-
	hosts the other way around.		hosts the other way around.
	+---------+		+---------+
	skipping to change at page 10, line 41		skipping to change at page 11, line 6
	| Host | 192.0.2.2		| Host | 192.0.2.2
	+------+		+------+
	[Fig. 6]		[Fig. 6]
	In the figure above, a site has native IPv4 and tunneled-IPv6		In the figure above, a site has native IPv4 and tunneled-IPv6
	connectivity. Therefore, the administrator may want to set a higher		connectivity. Therefore, the administrator may want to set a higher
	priority for using IPv4 than using IPv6 because the quality of the		priority for using IPv4 than using IPv6 because the quality of the
	tunnel network seems to be worse than that of the native transport.		tunnel network seems to be worse than that of the native transport.
			Solution analysis:
			This problem can be solved in the RFC 3484 framework. For
			example, configuring some address selection policies into Host's
			RFC 3484 policy table can solve this problem.
	2.2.2. ULA and IPv4 dual-stack environment		2.2.2. ULA and IPv4 dual-stack environment
	This is a special form of IPv4 and IPv6 prioritization. When an		This is a special form of IPv4 and IPv6 prioritization. When an
	enterprise has IPv4 Internet connectivity but does not yet have IPv6		enterprise has IPv4 Internet connectivity but does not yet have IPv6
	Internet connectivity, and the enterprise wants to provide site-local		Internet connectivity, and the enterprise wants to provide site-local
	IPv6 connectivity, a ULA is the best choice for site-local IPv6		IPv6 connectivity, a ULA is the best choice for site-local IPv6
	connectivity. Each employee host will have both an IPv4 global or		connectivity. Each employee host will have both an IPv4 global or
	private address and a ULA. Here, when this host tries to connect to		private address and a ULA. Here, when this host tries to connect to
	Host-C that has registered both A and AAAA records in the DNS, the		Host-C that has registered both A and AAAA records in the DNS, the
	host will choose AAAA as the destination address and the ULA for the		host will choose AAAA as the destination address and the ULA for the
	skipping to change at page 11, line 32		skipping to change at page 11, line 50
	| fd01:2:3:4::/64 (ULA)		| fd01:2:3:4::/64 (ULA)
	| 192.0.2.240/28		| 192.0.2.240/28
	------+---+----------		------+---+----------
	|		|
	+-+----+ fd01:2:3:4::100 (ULA)		+-+----+ fd01:2:3:4::100 (ULA)
	| Host | 192.0.2.245		| Host | 192.0.2.245
	+------+		+------+
	[Fig. 7]		[Fig. 7]
			Solution analysis:
			This problem can be solved in the RFC 3484 framework. For
			example, configuring some address selection policies into Host's
			RFC 3484 policy table can solve this problem.
	2.2.3. ULA or Global Prioritization		2.2.3. ULA or Global Prioritization
	Differentiating services by the client's source address is very		Differentiating services by the client's source address is very
	common. IP-address-based authentication is an typical example of		common. IP-address-based authentication is an typical example of
	this. Another typical example is a web service that has pages for		this. Another typical example is a web service that has pages for
	the public and internal pages for employees or involved parties. Yet		the public and internal pages for employees or involved parties. Yet
	another example is DNS zone splitting.		another example is DNS zone splitting.
	However, a ULA and IPv6 global address both have global scope, and		However, a ULA and IPv6 global address both have global scope, and
	RFC3484 default rules do not specify which address should be given		RFC3484 default rules do not specify which address should be given
	skipping to change at page 12, line 33		skipping to change at page 12, line 50
	| | 2001:db8:a:100::/64		| | 2001:db8:a:100::/64
	| | fc12:3456:789a:100::/64		| | fc12:3456:789a:100::/64
	--+-+---|-----		--+-+---|-----
	| |		| |
	+-+---|+ 2001:db8:a:100::100		+-+---|+ 2001:db8:a:100::100
	| Host | fc12:3456:789a:100::100		| Host | fc12:3456:789a:100::100
	+------+		+------+
	[Fig. 7]		[Fig. 7]
			Solution analysis:
			This problem can be solved in the RFC 3484 framework. For
			example, configuring some address selection policies into Host's
			RFC 3484 policy table can solve this problem.
	3. Conclusion		3. Conclusion
	We have covered problems related to destination or source address		We have covered problems related to destination or source address
	selection. These problems have their roots in the situation where		selection. These problems have their roots in the situation where
	end-hosts have multiple IP addresses. In this situation, every end-		end-hosts have multiple IP addresses. In this situation, every end-
	host must choose an appropriate destination and source address, which		host must choose an appropriate destination and source address, which
	cannot be achieved only by routers.		cannot be achieved only by routers.
	It should be noted that end-hosts must be informed about routing		It should be noted that end-hosts must be informed about routing
	policies of their upstream networks for appropriate address		policies of their upstream networks for appropriate address
	skipping to change at page 13, line 34		skipping to change at page 14, line 13
	and routing, these risks can be avoided.		and routing, these risks can be avoided.
	5. IANA Considerations		5. IANA Considerations
	This document has no actions for IANA.		This document has no actions for IANA.
	6. References		6. References
	6.1. Normative References		6.1. Normative References
	[I-D.ietf-v6ops-nap]
	Velde, G., "Local Network Protection for IPv6",
	draft-ietf-v6ops-nap-06 (work in progress), January 2007.
	[RFC3041] Narten, T. and R. Draves, "Privacy Extensions for		[RFC3041] Narten, T. and R. Draves, "Privacy Extensions for
	Stateless Address Autoconfiguration in IPv6", RFC 3041,		Stateless Address Autoconfiguration in IPv6", RFC 3041,
	January 2001.		January 2001.
	[RFC3484] Draves, R., "Default Address Selection for Internet		[RFC3484] Draves, R., "Default Address Selection for Internet
	Protocol version 6 (IPv6)", RFC 3484, February 2003.		Protocol version 6 (IPv6)", RFC 3484, February 2003.
	[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support		[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
	in IPv6", RFC 3775, June 2004.		in IPv6", RFC 3775, June 2004.
	skipping to change at page 14, line 15		skipping to change at page 14, line 36
	[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast		[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
	Addresses", RFC 4193, October 2005.		Addresses", RFC 4193, October 2005.
	[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing		[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
	Architecture", RFC 4291, February 2006.		Architecture", RFC 4291, February 2006.
	[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless		[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
	Address Autoconfiguration", RFC 4862, September 2007.		Address Autoconfiguration", RFC 4862, September 2007.
			[RFC4864] Van de Velde, G., Hain, T., Droms, R., Carpenter, B., and
			E. Klein, "Local Network Protection for IPv6", RFC 4864,
			May 2007.
			[RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6
			Socket API for Source Address Selection", RFC 5014,
			September 2007.
	6.2. Informative References		6.2. Informative References
	Appendix A. Appendix. Revision History		Appendix A. Appendix. Revision History
	01:		01:
	IP addresse notations changed to docmentation address.		IP addresse notations changed to docmentation address.
	Descriptoin of solutions deleted.		Descriptoin of solutions deleted.
	02:		02:
	Security considerations section rewritten according to comments		Security considerations section rewritten according to comments
	from SECDIR.		from SECDIR.
	03:		03:
	Intended status changed to Informational.		Intended status changed to Informational.
	04:		04:
	This version reflects comments from IESG members.		This version reflects comments from IESG members.
	05:		05:
	skipping to change at page 14, line 31		skipping to change at page 15, line 16
	Descriptoin of solutions deleted.		Descriptoin of solutions deleted.
	02:		02:
	Security considerations section rewritten according to comments		Security considerations section rewritten according to comments
	from SECDIR.		from SECDIR.
	03:		03:
	Intended status changed to Informational.		Intended status changed to Informational.
	04:		04:
	This version reflects comments from IESG members.		This version reflects comments from IESG members.
	05:		05:
	This version reflects comments from IESG members and Bob Hinden.		This version reflects comments from IESG members and Bob Hinden.
			06:
			This version reflects comments from Thomas Narten.
	Authors' Addresses		Authors' Addresses
	Arifumi Matsumoto		Arifumi Matsumoto
	NTT PF Lab		NTT PF Lab
	Midori-Cho 3-9-11		Midori-Cho 3-9-11
	Musashino-shi, Tokyo 180-8585		Musashino-shi, Tokyo 180-8585
	Japan		Japan
	Phone: +81 422 59 3334		Phone: +81 422 59 3334
	skipping to change at page 15, line 21		skipping to change at page 16, line 4
	Email: fujisaki@nttv6.net		Email: fujisaki@nttv6.net
	Ruri Hiromi		Ruri Hiromi
	Intec Netcore, Inc.		Intec Netcore, Inc.
	Shinsuna 1-3-3		Shinsuna 1-3-3
	Koto-ku, Tokyo 136-0075		Koto-ku, Tokyo 136-0075
	Japan		Japan
	Phone: +81 3 5665 5069		Phone: +81 3 5665 5069
	Email: hiromi@inetcore.com		Email: hiromi@inetcore.com
	Ken-ichi Kanayama		Ken-ichi Kanayama
	Intec Netcore, Inc.		Intec Netcore, Inc.
	Shinsuna 1-3-3		Shinsuna 1-3-3
	Koto-ku, Tokyo 136-0075		Koto-ku, Tokyo 136-0075
	Japan		Japan
	Phone: +81 3 5665 5069		Phone: +81 3 5665 5069
	Email: kanayama@inetcore.com		Email: kanayama_kenichi@intec-si.co.jp
	Full Copyright Statement		Full Copyright Statement
	Copyright (C) The IETF Trust (2008).		Copyright (C) The IETF Trust (2008).
	This document is subject to the rights, licenses and restrictions		This document is subject to the rights, licenses and restrictions
	contained in BCP 78, and except as set forth therein, the authors		contained in BCP 78, and except as set forth therein, the authors
	retain all their rights.		retain all their rights.
	This document and the information contained herein are provided on an		This document and the information contained herein are provided on an
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