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
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 38 skipping to change at page 1, line 38
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 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
 End of changes. 30 change blocks. 
67 lines changed or deleted 144 lines changed or added

This html diff was produced by rfcdiff 1.34. The latest version is available from http://tools.ietf.org/tools/rfcdiff/