Network Working Group B. Carpenter
Internet-Draft Univ. of Auckland
Intended status: Informational R. Atkinson
Expires: April 25, 2009 Extreme Networks
October 23, 2008
Renumbering still needs work
draft-carpenter-renum-needs-work-00
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Abstract
This document reviews the existing mechanisms for site renumbering
for both IPv4 and IPv6, and identifies operational issues with those
mechanisms. It also summarises current technical proposals for
additional mechanisms. Finally there is a gap analysis.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Existing Host-related Mechanisms . . . . . . . . . . . . . . . 4
2.1. DHCP . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. PPP . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3. IPv6 Stateless Address Auto-configuration . . . . . . . . 4
2.4. IPv6 ND Router/Prefix advertisements . . . . . . . . . . . 5
2.5. DNS configuration . . . . . . . . . . . . . . . . . . . . 6
3. Existing Router-related Mechanisms . . . . . . . . . . . . . . 6
3.1. Router renumbering . . . . . . . . . . . . . . . . . . . . 7
4. Operational Issues with Renumbering Today . . . . . . . . . . 7
4.1. Host-related issues . . . . . . . . . . . . . . . . . . . 7
4.1.1. Network layer issues . . . . . . . . . . . . . . . . . 7
4.1.2. Transport layer issues . . . . . . . . . . . . . . . . 9
4.1.3. DNS issues . . . . . . . . . . . . . . . . . . . . . . 9
4.1.4. Application layer issues . . . . . . . . . . . . . . . 10
4.2. Router-related issues . . . . . . . . . . . . . . . . . . 10
4.3. Other issues . . . . . . . . . . . . . . . . . . . . . . . 11
4.3.1. NAT state issues . . . . . . . . . . . . . . . . . . . 11
4.3.2. Mobility issues . . . . . . . . . . . . . . . . . . . 11
4.3.3. Multicast issues . . . . . . . . . . . . . . . . . . . 11
4.3.4. Management issues . . . . . . . . . . . . . . . . . . 11
4.3.5. Security issues . . . . . . . . . . . . . . . . . . . 12
5. Proposed Mechanisms . . . . . . . . . . . . . . . . . . . . . 12
5.1. SHIM6 . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2. MANET proposals . . . . . . . . . . . . . . . . . . . . . 13
6. Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.1. Host-related gaps . . . . . . . . . . . . . . . . . . . . 13
6.2. Router-related gaps . . . . . . . . . . . . . . . . . . . 13
6.3. Operational gaps . . . . . . . . . . . . . . . . . . . . . 13
6.4. Other gaps . . . . . . . . . . . . . . . . . . . . . . . . 13
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
10. Change log . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11. Informative References . . . . . . . . . . . . . . . . . . . . 14
Appendix A. Embedded IP addresses . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
Intellectual Property and Copyright Statements . . . . . . . . . . 18
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1. Introduction
[[ This is a first draft; some sections are incomplete. The authors
invite comments. ]]
In early 1996, the IAB published a short RFC entitled "Renumbering
Needs Work" [RFC1900], which the reader is urged to review before
continuing. Almost ten years later, the IETF published "Procedures
for Renumbering an IPv6 Network without a Flag Day" [RFC4192]. A few
other RFCs have touched on router or host renumbering: [RFC1916],
[RFC2071], [RFC2072], [RFC2874], [RFC2894], and [RFC4076].
In fact, since 1996, a number of atomic mechanisms have become
available to simplify some aspects of renumbering. The Dynamic Host
Configuration Protocol is available for IPv4 [RFC2131] and IPv6
[RFC3315]. IPv6 includes Stateless Address Autoconfiguration (SLAAC)
[RFC4862], and this includes Router Advertisements that include
options listing the set of active prefixes on a link. PPP [RFC1661],
[RFC5072] also automates address assignment for both versions of IP.
Despite these efforts, renumbering, especially for medium to large
sites and networks, is widely viewed as an expensive, painful and
error-prone process, and is therefore avoided by network managers as
much as possible. This has the highly unfortunate consequence that
any mechanisms for managing the scaling problems of wide-area (BGP4)
routing that require occasional or frequent site renumbering have
been consistently dismissed as unacceptable. This document aims to
explore the issues behind this problem statement, especially with a
view to identifying the gaps and known operational issues.
It is certainly to be expected that as the pressure on IPv4 address
space intensifies in the next few years, there will be many attempts
to consolidate usage of addresses so as to avoid wastage, as part of
the "end game" for IPv4. However, strategically, it is more
important to implement and deploy techniques for IPv6 renumbering, so
that as IPv6 becomes universally deployed, renumbering becomes viewed
as a relatively routine event. In particular, some mechanisms being
considered to allow indefinite scaling of the wide-area routing
system may assume site renumbering to be a straightforward matter.
IP addresses do not have a built-in lifetime. Even when an address
is leased for a finite time by DHCP or SLAAC, or when it is derived
from a DNS record with a finite time to live, this information is
lost once the address has been passed to an upper layer by the socket
interface. Thus, a renumbering event is almost certain to be an
unpredictable surprise from the point of view of any software using
the address. Many of the issues listed below derive from this fact.
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2. Existing Host-related Mechanisms
2.1. DHCP
At high level, DHCP [RFC2131] [RFC3315] offers similar support for
renumbering for both versions of IP. A host requests an address when
it starts up, the request may be delivered to a local DHCP server or
via a relay to a central server, and if all local policy requirements
are met, the server will provide an address with an associated
lifetime, and various other network-layer parameters (in particular,
the subnet mask and the default router address).
From an operational viewpoint, the interesting aspect is the local
policy. Do MAC addresses have to be pre-registered, or can any MAC
interface be given an IP address? Will the same IP address be
assigned to the same MAC address every time, according to a
predefined scheme? (In this case, DHCP is used to mimic manual fixed
address assignments.) Alternatively, will the IP addresses in a
subnet be assigned on a first-come, first-served basis?
These policy choices interact strongly with whether the site has what
might be called "strong" or "weak" asset management. At the strong
extreme, a site has a complete database of all equipment allowed to
be connected, certainly containing the MAC address(es) for each host
as well as administrative information of various kinds. Such a
database can be used to generate configuration files for DHCP, DNS
and any access control mechanisms that may be in use. For example,
only certain MAC addresses may be allowed to get an IP address on
certain subnets. At the weak extreme, a site has no asset
management, any MAC address may get a first-come first-served IP
address on any subnet, and there is no network layer access control.
A site that uses DHCP can in principle renumber its hosts by
reconfiguring DHCP for the new address range. The issues with this
are discussed below.
2.2. PPP
[[ Note - need some text from someone knowledgeable about PPP. ]]
2.3. IPv6 Stateless Address Auto-configuration
SLAAC, although updated recently [RFC4862], was designed prior to
DHCPv6, intended for networks where unattended automatic
configuration was preferred. Ignoring the case of an isolated
network with no router, which will use link-local addresses
indefinitely, SLAAC follows a bootstrap process. Each host first
gives itself a link-local address, and then needs to receive a link-
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local multicast Router Advertisement (RA) [RFC4861] which tells it
the routeable subnet prefix and the address(es) of the default
router(s). A node may either wait for the next regular RA, or
solicit one by sending a link-local multicast Router Solicitation.
Knowing the link prefix from the RA, the node may now configure its
own address. There are various methods for this, of which the basic
one is to construct a unique 64 bit identifier from the interface's
MAC address.
We will not describe here the processes of duplicate address
detection, neighbor discovery, and neighbor unreachability discovery.
Suffice it to say that they work, once the initial address assignment
based on the RA has taken place.
The contents of the RA message are clearly critical to this process
and its use during renumbering. An RA can indicate more than one
prefix, and more than one router can send RAs on the same link. For
each prefix, the RA indicates two lifetimes: "preferred" and "valid".
Addresses derived from this prefix must inherit its lifetimes. When
the valid lifetime expires, the prefix is dead and the derived
address must not be used any more. When the preferred lifetime is
expired (or set to zero) the prefix is deprecated, and must not be
used for any new sessions. Thus, setting a finite or zero preferred
lifetime is SLAAC's warning that renumbering will occur. SLAAC
assumes that the new prefix will be advertised in parallel with the
deprecated one, so that new sessions will use addresses configured
under the new prefix.
2.4. IPv6 ND Router/Prefix advertisements
With IPv6, a Router Advertisement not only advertises the
availability of an upstream router, but also advertises routing
prefix(es) valid on that link (subnetwork). Also, the IPv6 RA
message contains a flag indicating whether the host should use DHCPv6
to configure or not. If that flag indicates the host should use
DHCPv6, then the host is not supposed to auto-configure itself as
outlined in Section 2.3. However, there are some issues in this
area, described in Section 4.1.1.
In an environment where a site has more than one upstream link to the
outside world, the site might have more than one valid routing
prefix. In such cases, typically all valid routing prefixes within a
site will have the same prefix length. Also in such cases, it might
be desirable for hosts that have been told (via the IPv6 RA message)
to configure using DHCPv6 (rather than auto-configuring) to
dynamically learn about the availability of upstream links by
dynamically learning (from the periodic IPv6 RA messages) which
routing prefixes are currently valid. This application seems
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possible within the IPv6 Neighbour Discovery architecture, but this
application does not appear to be clearly specified anywhere. So at
present this approach for hosts learning about availability of new
upstream links or loss of prior upstream links is unlikely to work
with currently shipping hosts or routers.
2.5. DNS configuration
A site must provide DNS records for some or all of its hosts, and of
course these DNS records must be updated when hosts are renumbered.
Most sites will achieve this by maintaining a DNS zone file (or a
database from which it can be generated) and loading this file into
the site's DNS server(s) whenever it is updated. As a renumbering
tool, this is clumsy but effective. Clearly perfect synchronisation
between the renumbering of the host and the updating of its A or AAAA
record is impossible. The alternative is to use DNS dynamic update
[RFC3007], in which a host informs its own DNS server when it
receives a new address.
There are widespread reports that the freely available BIND DNS
software (which is what most UNIX hosts use), Microsoft Windows (XP
and later), and MacOS X all include support for Secure Dynamic DNS
Update. Further, there are credible reports that these
implementations are interoperable when configured properly ([dnsbook]
p. 228 and p. 506).
Commonly used commercial DNS and DHCP servers (e.g. MS Exchange)
often are deployed with Dynamic DNS also enabled. In some cases,
merely enabling both the DNS server and the DHCP server might enable
Dynamic DNS also ([dnsbook] p. 506). So in some cases, sites might
have deployed Dynamic DNS without realising it.
The network security community appears to believe that the current
DNS Security and Secure Dynamic DNS Update specifications are
reasonably secure for most deployment environments [RFC3007],
[RFC4033], [RFC4034], [RFC4035].
The authors note that at the time of this writing there appears to be
significantly more momentum towards rapid deployment of DNS Security
standards in the global public Internet than previously. See for
example and
.
3. Existing Router-related Mechanisms
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3.1. Router renumbering
Although DHCP was originally conceived for host configuration, it can
also be used for some aspects of router configuration. The DHCPv6
Prefix Delegation options [RFC3633] are intended for this. For
example, DHCPv6 can be used by an ISP to delegate or withdraw a
prefix for a customer's router, and this can be cascaded throughout a
site to achieve router renumbering. [[ Say more. ]]
An ICMPv6 extension to allow router renumbering for IPv6 is specified
in [RFC2894], but there appears to be little experience with it. It
is not suggested as a useful mechanism by [RFC4192].
4. Operational Issues with Renumbering Today
For IPv6, a useful description of practical aspects was drafted in
[I-D.chown-v6ops-renumber-thinkabout], as a complement to [RFC4192].
[[ Note: need to extract issues from that draft. ]]
4.1. Host-related issues
4.1.1. Network layer issues
For IPv4, the vast majority of client systems (PCs and workstations)
today use DHCP to obtained their addresses and other network layer
parameters. Since DHCP provides for lifetimes after which the
address lease expires, it should be possible to devise an operational
procedure in which lease expiry coincides with the moment of
renumbering (within some margin of error). In this case it would be
the DHCP server itself that automatically accomplishes client
renumbering, although this would cause a peak of DHCP traffic and
therefore would not be instantaneous. DHCPv6 could accomplish a
similar result. It has a useful extra feature, a "reconfig-init"
message that can be sent to all hosts to inform them to check their
DHCPv6 server for an update.
Using such an approach with DHCP will be very different depending
whether the site uses strong or weak asset management. With strong
asset management, and careful operational planning, the subnet
addresses and masks will be updated in the database, and a script
will be run to regenerate the DHCP MAC-to-IP address tables and the
DNS zone file. DHCP and DNS timers will be set temporarily to small
values. The DHCP and DNS servers will be fed the new files, and as
soon as the previous DHCP leases and DNS TTLs expire, everything will
follow automatically, as far as the host IP layer is concerned. In
contrast, with weak asset management, and a casual operational
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approach, the DHCP table will be reconfigured by hand, the DNS zone
file will be edited by hand, and when these configurations are
installed, there will be a period of confusion until the old leases
and TTLs expire. The DHCPv6 "reconfig-init" message could shorten
this confusion to some extent.
DHCP, particularly for IPv4, has acquired a very large number of
additional capabilities, with approximately 170 options defined at
the time of this writing. Although most of these do not carry IP
address information, some do (for example, options 68 through 76 all
carry various IP addresses). Thus, renumbering mechanisms involving
DHCP have to take into account more than the basic DHCP job of
leasing an address to each host.
SLAAC is much less overloaded with options than DHCP; in fact its
only extraneous capability is the ability to convey a DNS server
address. Using SLAAC to force all hosts on a site to renumber is
therefore less complex than DHCP, and the difference between strong
and weak asset management is less marked. The principle of
synchronising the SLAAC and DNS updates, and of reducing the the
lease time and TTL, does not change.
We should note a currently unresolved ambiguity in the interaction
between DHCPv6 and SLAAC from the host's point of view. RA messages
include a 'Managed Configuration' flag known as the M bit, which is
supposed to indicate that DHCPv6 is in use. However, it is
unspecified whether hosts must interpret this flag rigidly (i.e. only
start DHCPv6 if it is set, or if no RAs are received) or whether
hosts are allowed or are recommended to start DHCPv6 by default. An
added complexity is that DHCPv6 has a 'stateless' mode [RFC3736] in
which SLAAC is used to obtain an address but DHCPv6 is used to obtain
other parameters. Another flag in RA messages, the 'Other
configuration' or O bit, indicates this.
Until this ambiguous behaviour is clearly resolved by the IETF,
operational problems are to be expected. Also, it should be noted
that on an isolated LAN, neither RA nor DHCPv6 responses will be
received, and the host will remain with only its self-assigned link-
local address. One could also have a situation where a multihomed
network uses SLAAC for one address prefix and DHCPv6 for another,
which would clearly create a risk of inconsistent host behavior and
operational confusion.
The SLAAC approach, or DHCP without pre-registered MAC addresses, do
not work for servers, or for any other systems that are assigned
fixed IP addresses for historical reasons. Manual or script-driven
procedures, likely to be site-specific and definitely prone to human
error, are needed. Unless a site has no hosts with fixed addresses,
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completely automatic host renumbering is therefore very unlikely to
be possible.
The above assumes the use of typical off-the-shelf hardware and
software. There are other environments, often referred to as
embedded systems, where DHCP or SLAAC may not be used and even
configuration scripts are not an option; for example, fixed IP
addresses may be stored in read-only memory. Such systems create
special problems that no general-purpose solution is likely to
address.
4.1.2. Transport layer issues
TCP connections and UDP flows are rigidly bound to a given pair of IP
addresses. These are included in the checksum calculation and there
is no provision for them to change. It is therefore fundamentally
impossible for the flows to survive a renumbering event at either
end. From an operational viewpoint, this means that a site that
plans to renumber itself is obliged either to follow the overlapped
procedure described in [RFC4192], or to announce a site-wide outage
for the renumbering process, during which all user sessions will
fail. In the case of IPv4, overlapping of the old and new addresses
is unlikely to be an option, and in any case is not commonly
supported by software. Therefore, absent enhancements to TCP and UDP
to enable dynamic endpoint address changes (for example, [handley]).
interruptions to TCP and UDP sessions seem inevitable if renumbering
occurs at either session endpoint. The same appears to be true of
DCCP [RFC4340].
In contrast, SCTP already supports dynamic multi-homing of session
end-points, so SCTP sessions ought not be adversely impacted by
renumbering the SCTP session end-points [RFC4960], [RFC5061].
4.1.3. DNS issues
The main issue is whether the site in question has a systematic
procedure for updating its DNS configuration. If it does, updating
the DNS for a renumbering event is essentially a clerical issue that
must be coordinated as part of a complete plan. As mentioned in
[RFC4192], the DNS TTL will be manipulated to ensure that stale
addresses are not cached. However, if the site uses a weak asset
management model in which DNS updates are made manually on demand,
there will be a substantial period of confusion and errors will be
made.
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4.1.4. Application layer issues
Ideally, we would carry out a renumbering analysis for each
application protocol. To some extent, this has been done, in
[RFC3795]. This found that 34 out of 257 standards-track or
experimental application layer RFCs had explicit address
dependencies. Although this study was made in the context of IPv4 to
IPv6 transition, it is clear that all these protocols might be
sensitive to renumbering. However, the situation is worse, in that
there is no way to discover by analysing specifications whether an
actual implementation is sensitive to renumbering. Indeed, such
analysis may be quite impossible in the case of proprietary
applications.
The sensitivity depends on whether the implementation stores IP
addresses in such a way that it may refer back to them later, without
allowing for the fact that they may no longer be valid. In general,
we can assert that any implementation that does not check that an
address is valid (e.g., by resolving relevant FQDNs again) each time
it opens a new communications session is at risk from renumbering.
There are quite egregious breaches of this principle, for example
software license systems that depend on the licensed host computer
having a particular IP address. Other examples are the use of
literal IP addresses in URLs, HTTP cookies, or application proxy
configurations. (Also see Appendix A.)
4.2. Router-related issues
[RFC2072] gives a detailed review of the operational realities in
1997. A number of the issues discussed in that document were the
result of the relatively recent adoption of classless addressing;
those issues can be assumed to have vanished by now. Also, DHCP was
a relative newcomer at that time, and can now be assumed to be
generally available. Above all, the document underlines that
systematic planning and administrative preparation is needed, and
that all forms of configuration file and script must be reviewed and
updated. Clearly this includes filtering and routing rules (e.g.
when peering with BGP, but also with intradomain routing as well).
Two particular issues mentioned in [RFC2072] are:
o Addresses are cached in routers - routers may need to be
restarted.
o Addresses used by configured tunnels [and today, VPNs] may be
overlooked.
In IPv6, if a site wanted to be multi-homed using multiple provider-
aggregated (PA) routing prefixes with one prefix per upstream
provider, then the interior routers would need a mechanism to learn
which upstream providers and prefixes were currently reachable (and
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valid). In this case their Router Advertisement messages could be
updated dynamically to only advertise currently valid routing
prefixes to hosts. This would be significantly more complicated if
the various provider prefixes were of different lengths or if the
site had non-uniform subnet prefix lengths.
4.3. Other issues
4.3.1. NAT state issues
When a renumbering event takes place, entries in the state table of
any Network Address Translator that happen to contain the affected
addresses will become invalid and will eventually time out. Since
TCP and UDP sessions are unlikely to survive renumbering anyway, the
hosts involved will not be additionally affected. The situation is
more complex for multihomed SCTP [I-D.xie-behave-sctp-nat-cons],
depending whether a single or multiple NATs are involved.
A NAT itself may be renumbered and may need a configuration change
during a renumbering event.
4.3.2. Mobility issues
A mobile node using Mobile IP that is not currently in its home
network will be affected if either its current care-of address or its
home address is renumbered. [[ Expert input required. ]]
4.3.3. Multicast issues
[[ Can be found in [I-D.chown-v6ops-renumber-thinkabout] ]]
4.3.4. Management issues
Today, IP addresses are routinely embedded in numerous configuration
files and network management databases, including MIBs. Ideally, all
these would be generated from a single central asset management
database for a given site, but this is far from being universal
practice. Furthermore, because of routing policies and VPNs, a site
or network may well embed addresses from other sites or networks in
its own configuration data. Thus renumbering will cause a ripple
effect of updates for a site and for its neighbours. To the extent
that these updates are manual, they will be costly and prone to
error.
Use of FQDNs rather than raw IP addresses wherever possible in
configuration files and databases might reduce/mitigate the potential
issues arising from such configuration files or management databases
when renumbering is required or otherwise occurs. However, by
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definition there is then at least one place (i.e. the DNS zone file
or the database that it is derived from) where address information is
nevertheless inevitable.
It should be noted that the management and administration issues
(i.e. tracking down, recording, and updating all instances where
addresses are stored rather than looked up dynamically) is the
dominant concern of managers considering the renumbering problem.
This has led to a strong managerial preference for continuing the
pre-CIDR approach of a provider-independent (PI) prefix, or even for
using private addressing and NAT as a matter of choice rather than
obligation. The direct cost of renumbering is perceived to exceed
the indirect costs of these alternatives. Additionally, there is a
risk element stemming from the complex dependencies of renumbering:
it is hard to be fully certain that the renumbering will not cause
unforeseen service disruptions, leading to unknown additional costs.
4.3.5. Security issues
Firewall rules will certainly need to be updated, and any other cases
where addresses or address prefixes are embedded in security
components (access control lists, AAA systems, intrusion detection
systems, etc.).
There will be operational and security issues if an X.509v3 PKI
Certificate includes a subjectAltName extension that contains an
iPAddress [RFC5280], and if the corresponding node then undergoes an
IP address change without a concurrent update to the node's PKI
Certificate. For these reasons, use of the dNSName rather than the
iPAddress is recommended for the subjectAltName extension. Any other
use of IP addresses in cryptographic material is likely to be
similarly troublesome.
If a site is for some reason listed by IP address in a white list
(such as a spam white list) this will need to be updated.
Conversely, a site which is listed in a black list can escape that
list by renumbering itself.
5. Proposed Mechanisms
5.1. SHIM6
SHIM6, proposed as a host-based multihoming mechanism for IPv6, has
the property of switching addresses dynamically in the actual packet
stream while presenting a constant upper layer identifier to the
transport layer [I-D.ietf-shim6-proto]. At least in principle, this
property could be used during renumbering to alleviate the problem
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described in Section 4.1.2.
5.2. MANET proposals
The IETF working groups dealing with mobile ad-hoc networks have been
working on a number of mechanisms for mobile routers to discover
available border routers dynamically, and for those mobile routers to
be able to communicate that information to hosts connected to those
mobile routers. This work continues.
Recently, some MANET work has appeared on a Border Router Discovery
Protocol that might be useful work towards a more dynamic mechanism
for site interior router renumbering [I-D.boot-autoconf-brdp].
At present, the IETF AutoConf WG
[] is
working on address auto-configuration mechanisms for MANET networks
that seem likely to be useful for ordinary non-mobile non-MANET
networks also [I-D.ietf-autoconf-manetarch]. Other work in the same
area, e.g. [I-D.templin-autoconf-dhcp], may also be relevant.
6. Gaps
6.1. Host-related gaps
TBD
6.2. Router-related gaps
TBD
6.3. Operational gaps
TBD
6.4. Other gaps
TBD
7. Security Considerations
TBD
[[ Notes:
A. Some sort of authentication capability ought to be available for
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sites that want this.
B. SEND appears to be very difficult to actually deploy and operate.
At present it is unclear whether or when SEND might be widely
implemented or widely deployed.
C. Key distribution is normally the hard part, rather than the actual
authentication mechanism.
D. Issues for privacy addresses?. ]]
8. IANA Considerations
This document requires no action by the IANA.
9. Acknowledgements
Useful comments and suggestions were made by Hannu Flinck.
This document was produced using the xml2rfc tool [RFC2629].
10. Change log
draft-carpenter-renum-needs-work-00: original version, 2008-10-23
11. Informative References
[I-D.boot-autoconf-brdp]
Boot, T. and A. Holtzer, "Border Router Discovery Protocol
(BRDP) based Address Autoconfiguration",
draft-boot-autoconf-brdp-00 (work in progress), July 2008.
[I-D.chown-v6ops-renumber-thinkabout]
Chown, T., "Things to think about when Renumbering an IPv6
network", draft-chown-v6ops-renumber-thinkabout-05 (work
in progress), September 2006.
[I-D.ietf-autoconf-manetarch]
Chakeres, I., Macker, J., and T. Clausen, "Mobile Ad hoc
Network Architecture", draft-ietf-autoconf-manetarch-07
(work in progress), November 2007.
[I-D.ietf-shim6-proto]
Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
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Shim Protocol for IPv6", draft-ietf-shim6-proto-10 (work
in progress), February 2008.
[I-D.templin-autoconf-dhcp]
Templin, F., "Virtual Enterprise Traversal (VET)",
draft-templin-autoconf-dhcp-18 (work in progress),
October 2008.
[I-D.xie-behave-sctp-nat-cons]
Xie, Q., Stewart, R., Holdrege, M., and M. Tuexen, "SCTP
NAT Traversal Considerations",
draft-xie-behave-sctp-nat-cons-03 (work in progress),
November 2007.
[RFC1661] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51,
RFC 1661, July 1994.
[RFC1900] Carpenter, B. and Y. Rekhter, "Renumbering Needs Work",
RFC 1900, February 1996.
[RFC1916] Berkowitz, H., Ferguson, P., Leland, W., and P. Nesser,
"Enterprise Renumbering: Experience and Information
Solicitation", RFC 1916, February 1996.
[RFC2071] Ferguson, P. and H. Berkowitz, "Network Renumbering
Overview: Why would I want it and what is it anyway?",
RFC 2071, January 1997.
[RFC2072] Berkowitz, H., "Router Renumbering Guide", RFC 2072,
January 1997.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol",
RFC 2131, March 1997.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
[RFC2874] Crawford, M. and C. Huitema, "DNS Extensions to Support
IPv6 Address Aggregation and Renumbering", RFC 2874,
July 2000.
[RFC2894] Crawford, M., "Router Renumbering for IPv6", RFC 2894,
August 2000.
[RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic
Update", RFC 3007, November 2000.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
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and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633,
December 2003.
[RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol
(DHCP) Service for IPv6", RFC 3736, April 2004.
[RFC3795] Sofia, R. and P. Nesser, "Survey of IPv4 Addresses in
Currently Deployed IETF Application Area Standards Track
and Experimental Documents", RFC 3795, June 2004.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, March 2005.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, March 2005.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005.
[RFC4076] Chown, T., Venaas, S., and A. Vijayabhaskar, "Renumbering
Requirements for Stateless Dynamic Host Configuration
Protocol for IPv6 (DHCPv6)", RFC 4076, May 2005.
[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
Renumbering an IPv6 Network without a Flag Day", RFC 4192,
September 2005.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
September 2007.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007.
[RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
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Kozuka, "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration", RFC 5061,
September 2007.
[RFC5072] S.Varada, Haskin, D., and E. Allen, "IP Version 6 over
PPP", RFC 5072, September 2007.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[dnsbook] Albitz, P. and C. Liu, "DNS and BIND (5th edition)", 2006.
[handley] Handley, M., Wischik, D., and M. Bagnulo, "Multipath
Transport, Resource Pooling, and implications for
Routing", 2008,
.
Appendix A. Embedded IP addresses
This Appendix lists common places where IP addresses may be embedded.
[[ Can be found in [I-D.chown-v6ops-renumber-thinkabout] ]]
Authors' Addresses
Brian Carpenter
Department of Computer Science
University of Auckland
PB 92019
Auckland, 1142
New Zealand
Email: brian.e.carpenter@gmail.com
Randall Atkinson
Extreme Networks
PO Box 14129
3306 East NC Highway 54, Suite 100
Research Triangle Park, NC 27709
USA
Email: rja@extremenetworks.com
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