Network Working Group B. Liu
Internet Draft S. Jiang
Intended status: Informational Huawei Technologies Co., Ltd
Expires: January 11, 2012 July 11, 2011
IPv6 Site Renumbering Gap Analysis
draft-liu-6renum-gap-analysis-01.txt
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Abstract
This document briefly introduces the existing mechanisms could be
utilized by IPv6 site renumbering and envisions the effort could be
done. This document tries to cover the most explicit issues and
requirements of IPv6 renumbering. Through the gap analysis, the
document provides a basis for future work to identify and develop
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solutions or to stimulate such development as appropriate. The gap
analysis is presented following a renumbering event procedure clue.
Table of Contents
1. Introduction ................................................ 3
2. Overall Requirements for Renumbering ........................ 3
3. Existing Components for IPv6 Renumbering .................... 4
3.1. Relevant Protocols and Mechanisms .................... 4
3.2. Management Tools ....................................... 4
3.3. Procedures/Policies .................................... 5
4. Managing Prefixes ........................................... 5
4.1. Prefix Delegation ...................................... 5
4.2. Prefix Assignment ...................................... 5
5. Address Configuration ....................................... 6
5.1. Host Address Configuration ............................. 6
5.2. Router Address Configuration ........................... 7
5.3. Static Address Configuration ........................... 8
6. Address Relevant Entries Update ............................. 9
6.1. DNS Records Update ..................................... 9
6.2. In-host Server Address Update ......................... 10
6.3. Filters ............................................... 10
7. Renumbering Event Management ............................... 11
7.1. Renumbering Notification .............................. 11
7.2. Synchronization Management ............................ 12
7.3. Renumbering Monitoring........................... ..... 12
8. Miscellaneous .............................................. 12
8.1. Multicast ............................................. 12
8.2. Mobility .............................................. 13
9. Gap Summary ................................................ 13
9.1. Managing Prefixes ..................................... 13
9.2. Address configuration ................................. 13
9.3. Address relevant entries update ....................... 14
9.4. Renumbering event management .......................... 15
10. Security Considerations ................................... 15
11. IANA Considerations ....................................... 16
12. References ................................................ 16
12.1. Normative References ................................. 16
12.2. Informative References ............................... 17
13. Acknowledgments ........................................... 17
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1. Introduction
As introduced in [RFC5887], renumbering, especially for medium to
large sites and networks, is currently viewed as an expensive,
painful, and error-prone process, avoided by network managers as much
as possible. If IPv6 site renumbering continues to be considered
difficult, network managers will turn to Provider Independent (PI)
addressing for IPv6 to attempt to minimize the need for future
renumbering. However, widespread use of PI may create very serious
BGP4 scaling problems. It is thus desirable to develop tools and
practices that may make renumbering a simpler process to reduce
demand for IPv6 PI space.
This document performs a gap analysis to provide a basis for future
work to identify and develop solutions or to stimulate such
development as appropriate. Gap analysis draws on existing work in
(at least) [RFC5887] and [RFC4192]. The [I-D.jiang-6renum-enterprise]
contributions are incorporated into the more detailed gap analysis.
In this document, we discuss the overall requirements for
renumbering. The gap analysis is organized by the main steps of
renumbering process, which include the prefix management, the node
address (re)configuration, and address relevant entries update in
various gateways, routers and servers, etc. Besides the steps, a sub-
clause of renumbering event management is presented independently,
which targets to help the operational/administrative process.
2. Overall Requirements for Renumbering
This section introduces the overall ultimate goals we want to achieve
in renumbering event. Some existing mechanisms have already provide
useful help. Further efforts may be achieved in the future.
o Prefix delegation and delivery should be automatic and accurate in
aggregation and coordination.
o Address reconfiguration should be automatically achieved through
standard protocols with minimum human intervene.
o Address relevant entries update should be processed integrally and
error-prevented. [Open Question]Is it necessary to develop
automatic entries update mechanisms? If necessary, do we need
standard protocols/interface for it?
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o [Open Question] Is it necessary/possible to develop a ''One-Click''
fully automatic renumbering technology? What scenarios have the
potential possibility?
o [Open Question] Is session survivability within our scope?
3. Existing Components for IPv6 Renumbering
3.1. Relevant Protocols and Mechanisms
Generally, renumbering is achieved by utilizing existing protocols
rather than dedicated renumbering protocols.
o RA messages, defined in [RFC4861], are used to deprecate/announce
old/new prefixes and to advertise the availability of an upstream
router. In renumbering, it is one of basic mechanisms for host
configuration.
o When a host is renumbered, it may use SLAAC [RFC4862] for address
configuration with the new prefix. Hosts receive RA messages which
contain routable prefix(es) and the address(es) of the default
router(s), then hosts can generate IPv6 address(es) by themselves.
o Hosts configured through DHCPv6 [RFC3315] can reconfigure
addresses by initialing RENEW sessions when the current addresses'
lease time are expired or they receive the reconfiguration
messages initiatedinitiated by the DHCPv6 servers.
o DHCPv6-PD (Prefix Delegation) [RFC3633] enables automated
delegation of IPv6 prefixes using the DHCPv6. initiated
o [RFC2894] defined standard ICMPv6 messages for router renumbering.
This is a dedicated protocol for renumbering, but has not been
widely used.
3.2. Management Tools
Some operations of renumbering could be automatically processed by
management tools in order to make the renumbering process more
efficient and accurate. The tools may be designed dedicated for
renumbering or just common tools could be utilized for some
operations in renumbering.
Following are samples of the tools.
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o [LEROY] proposed a mechanism of macros to automatically update the
address relevant entries/configurations inside the DNS, firewall,
etc. The macros can be delivered though SOAP protocol from a
network management server to the managed devices.
o Asset management tools/systems. These tools may provide the
ability of managing configuration files in nodes so that it is
convenient to update the address relevant configuration in these
nodes.
3.3. Procedures/Policies
o [RFC4192] proposed a procedure for renumbering an IPv6 network
without a flag day. The document includes a set of operational
suggestions which can be followed step by step by network
administrators.
o [I-D.jiang-6renum-enterprise] analyzes the enterprise renumbering
events and gives the recommendations among the existing
renumbering mechanisms. According to the different stages,
renumbering considerations are described in three categories:
considerations and recommendations during network design, for
preparation of enterprise network renumbering, and during
renumbering operation
4. Managing Prefixes
When renumbering an enterprise site, a short prefix may be divided
into longer prefixes for subnets. So we need to carefully manage the
prefixes for prefix delivery, delegation, aggregation,
synchronization, coordination, etc.
4.1. Prefix Delegation
Usually, the short prefix comes down from the operator and received
by DHCPv6 server or router inside the enterprise network. The short
prefix could be automatically delegated through DHCPv6-PD. Then the
downlink DHCP servers or routers can begin advertising the longer
prefixes to the subnets.
4.2. Prefix Assignment
When subnet routers receive the longer prefixes, they can directly
assign them to the hosts. The prefix assignment overlaps with the
host address configuration, which is described in the following
section 5.1.
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5. Address Configuration
5.1. Host Address Configuration
Both of the DHCPv6 and ND protocols have IP address configuration
function. They are suitable for different scenarios respectively.
During renumbering, the SLAAC-configured hosts can reconfigure IP
addresses by receiving ND Router Advertisement (RA) messages
containing new prefix information (It should be noted that, the
prefix delivery could be achieved through DHCP according to the new
IETF DHC WG document [I.D ietf-dhc-host-gen-id]). The DHCPv6-
configured hosts can reconfigure addresses by initiating RENEW
sessions when the current addresses' lease time are expired or
receiving the reconfiguration messages initiated by the DHCPv6
servers.
o SLAAC and DHCPv6 address configuration co-existence
While an IPv6 site is being renumbered, both DHCPv6 and ND may
be used to reconfigure the host addresses. The co-existence
issue mainly includes following aspects:
- Dynamic upstream learning
[RFC5887] mentioned that, DHCP-configured hosts may want to
learn about the upstream availability of new prefixes or loss
of prior prefixes dynamically by deducing from periodic RA
messages. But there is no standard specifying what approach
should be taken by a DHCPv6-configured host when it receives
RA messages containing new prefix. It depends on the operation
system of the host and cannot be predicted or controlled by
the network.
- DHCP/SLAAC conflict
If the DHCP-managed host accepts the new prefix in RA, it may
violet the DHCPv6-managed policies. But if it ignores the RA
messages and there are no DHCPv6 reconfiguration messages
received either, the renumbering would fail. What is worse,
the host may even receive both the RA messages and DHCP-v6
reconfiguration messages and finds the prefixes in the two
protocols are different. This means serious network
configuration error occurring.
[Open Question]It is hard for the host to identify the RA
messages containing new prefix(es) representing adding an
uplink or conflict caused by network configuration mistake.
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- SLAAC-configured hosts finding DHCPv6 in use
[RFC5887] mentioned RA message of ND protocol contains a
"Managed Configuration" flag to indicate DHCPv6 is in use. But
it is unspecified what behavior should be taken when the host
receives RA messages with "M" set to 1. The gap of standard
will cause ambiguous host behavior because it depends on the
operation system of the host.
The host may start a DHCPv6 session and receives the DHCPv6
address configuration. It is also possible that the host finds
the DHCPv6 assigned prefix is different from the prefix in the
RA messages, which means multiple uplinks are available or
there is a serious network configuration error.
Another possibility is that the host may receive no response
from any DHCPv6 servers, which means the DHCPv6 service is not
available and the "Managed Configuration" flag was mis-
configured.
o DHCPv6 reconfigure bulk usage
[RFC5887] mentioned that ''DHCPv6 reconfiguration doesn't appear
to be widely used for bulk renumbering purposes''.
[Open Question] Using DHCPv6 reconfiguration can be considered
as ''stateful'' renumbering which need sessions maintained between
DHCP servers and clients. So maybe it is too heavy for the
servers. So is it possible for bulk renumbering? Is there any
requirement?
o RA prefix lifetime limitation
In section 5.5.3 of [RFC4862], it is defined that ''If the
received Valid Lifetime is greater than 2 hours or greater than
RemainingLifetime, set the valid lifetime of the corresponding
address to the advertised Valid Lifetime.'' So when renumbering,
if the previous RemainingLifetime is longer than two hours, it
is impossible to reduce a prefix's lifetime less than two hours.
This limitation is to prevent denial-of-service attack.
[Open Question]This limitation requires renumbering to be
planned in advance so that an immediate renumbering event is
impossible. Should it be considered as a standard gap for
renumbering?
5.2. Router Address Configuration
o Learning new prefixes
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As described in [RFC5887], ''if a site wanted to be multihomed
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 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.''
o Restart after renumbering
"Some routers cache IP addresses in some situations. So routers
might need to be restarted as a result of site renumbering"
[RFC2072].
After investigation, it seems (need further confirmation) this
caused by individual implementation and only happen on the old
type of routers. Therefore, it is not an issue anymore.
o Router naming
In [RFC4192], it is suggested that ''To better support
renumbering, switches and routers should use domain names for
configuration wherever appropriate, and they should resolve
those names using the DNS when the lifetime on the name
expires.''
As [RFC5887] described, this capability is not new, and at least
it is present in most IPsec VPN implementations. But many
administrators do not realize that it could be utilized to avoid
manual modification during renumbering.
[Open Question]Whether it is not easy to use or just suitable in
few situations needs further investigation.
5.3. Static Address Configuration
Further gap analysis about static address issue could consider the
following suggestions (proposed by George Wesley in the mail list).
o Documenting how to limit the places where static addresses must be
used (vs FQDN or autoconf).
o Identifying gaps and proposing solutions in other areas to reduce
the number of places that static addresses are required.
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o Documenting any gaps in [RFC4192] to make renumbering easier for a
statically-numbered set of hosts and potentially identifying a
problem statement for improving renumbering for static.
[Open Question]Besides the open questions above, the ULA utilization
issue may also need consideration.
6. Address Relevant Entries Update
When nodes in a site have been renumbered, then all the entries in
the site which contain the nodes' addresses must be updated. The
entries mainly include DNS records and filters in various entities
such as ACLs in firewalls/gateways.
6.1. DNS Records Update
o DNS update automation
For DNS records update, most sites will achieve it by
maintaining a DNS zone file and loading this file into the
site's DNS server(s). Synchronization between host renumbering
and the updating of its A6 or AAAA record is hard. [RFC5887]
mentioned that an alternative is to use Secure Dynamic DNS
Update [RFC3007], in which a host informs its own DNS server
when it receives a new address. But Secure Dynamic DNS Update
hasn't been widely deployed.
[Open Question]To popularize the [RFC3007] or to develop a
lightweight dedicated protocol for this need to be considered.
DNS entries commonly have matching Reverse DNS entries which
will also need to be updated during renumbering.
[Open Question]So synchronizing the procedures of forward and
reverse DNS or even combining forward and reverse DNS updates in
a single procedure also need to be considered.
o DNS data structure optimization
[RFC2874] proposed a new A6 record type for DNS recording IPv6
address/prefix. And several extensions on query and processing
were also proposed. With the A6 record and the extensions, an
IPv6 address can be defined by using multiple DNS records. This
feature increases the complexity of resolver but reduce the cost
of zone file maintenance. So renumbering could be easier than
AAAA record. But the [RFC2874] has not been widely used.
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[Open Question]Is the DNS data structure optimization such as
[RFC2874] necessary for easing renumbering? If necessary, is the
optimization in [RFC2874] enough?
o DNS authority
As described in [I-D.chown-v6ops-renumber-thinkabout], ''it is
often the case in enterprises that host web servers and
application servers on behalf of collaborators and customers
that DNS zones out of the administrative control of the host
maintain resource records concerning addresses for nodes out of
their control. When the service host renumbers, they do not have
sufficient authority to change the records.''
[Open Question]Whether it is only an operational issue or
additional protocol/mechanism is needed to standardize the
interaction between DNS systems needs to be considered.
6.2. In-host Server Address Update
While DNS records addresses of hosts in servers, hosts also record
addresses of servers such as DNS server, radius server, etc. While
renumbering, the hosts must update the records if the server
addresses changed. Addresses of DHCPv6 servers do not need to be
updated. They are dynamic discovered using DHCPv6 relevant multicast
addresses.
o The DNS server addresses for hosts are configured by DHCPv6. But
current DHCPv6 messages do not indicate hosts the lifetimes of DNS.
If the DNS lifetime expired and has been renumbered, the hosts may
still use the old addresses. DHCPv6 should be extended to indicate
hosts the associated DNS lifetimes when making DNS configuration.
How does the DHCP server could know about the DNS lifetime is
another issue.
6.3. Filters
o Filters Management
Filters based on addresses or prefixes are usually spread in
various devices. As [RFC5887] described, some address
configuration data might be widely dispersed and much harder to
find, even will inevitably be found only after the renumbering
event. So there's a big gap for filter management.
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In [LEROY], a server is used for managing filter update in
various devices. But identifying where and which of the filters
need to be updated during renumbering is still a gap.
o Filter Update Automation Operation
As mentioned in section 3.2, [LEROY] proposed a mechanism which
can automatically update the filters. The mechanism utilizes
macros suitable for various devices such as routers, firewalls
etc. to update the filter entries based on the new prefix. Such
automation tool is valuable for renumbering because it can
reduce manual operation which is error-prone and inefficiency.
[Open Question]Besides the macros, [LEROY] also proposed to use
SOAP to deliver the macros to the devices. So there may be
requirement of protocol standardization. [LEROY] uses
application layer protocol while we may consider whether it is
possible and suitable to use network layer protocol.
[Open Question] Update of filters based on prefixes and filters
based on addresses may have different requirements and methods.
For example, the prefix-based filters may consider to be updated
though DHCPv6 server, which may provide better efficient.
7. Renumbering Event Management
From the perspective of network management, renumbering is a kind of
event which may need additional process to make the process more easy
and manageable.
7.1. Renumbering Notification
If hosts or servers are aware of a renumbering event happening, it
may help the relevant process. Following are several examples of such
additional process may ease the renumbering. Further contributions
are expected.
o A notification mechanism may be needed to indicate the hosts that
a renumbering event of local recursive DNS happen or is going to
take place.
o [RFC4192] suggests that ''reducing the delay in the transition to
new IPv6 addresses applies when the DNS service can be given prior
notice about a renumbering event.'' Reducing delay could improve
the efficiency of renumbering.
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7.2. Synchronization Management
o DNS update synchronization
DNS update synchronization focuses on the coordinating between
DNS and other entities/mechanims, for example, as described in
[RFC5887], synchronizing the SLAAC and DNS updates, and of
reducing the SLAAC lease time and DNS TTL.
[Gaps TBD]
7.3. Renumbering Monitoring
While treating renumbering a network event, mechanisms to monitor the
renumbering process may be needed. Considering the address
configuration operation may be stateless(if ND is used for
renumbering), it is difficult for monitoring. But for the DNS and
filter update, it is quite possible to monitor the whole process.
[Gaps TBD]
8. Miscellaneous
8.1. Multicast
o The embedding of IPv6 unicast addresses into multicast addresses
and the embedded-RP (Rendezvous Point)[RFC3956] will cause issues
when renumbering.
As [I-D.chown-v6ops-renumber-thinkabout] described, ''If the RP
address changes, then the group addresses must also be changed.
This may happen not only when a site is renumbered, but also if
a site is restructured or the RP is moved within the site. The
embedded address is used by routers to determine the RP address.
Applications must use new group addresses once the RP is not
available on the old address.''
o Changing the unicast source address of a multicast sender might
also be an issue for receivers.
As [I-D.chown-v6ops-renumber-thinkabout] described, ''If a site's
unicast prefix changes, then one will also need to change the
multicast addresses. By way of example, a site renumbering away
from prefix 2001:DB8:BEEF::/48" might have globally-scoped
multicast addresses in use under the prefix
"FF3E:30:2001:DB8:BEEF::/96". One may continue using the old
addresses for a while, but this should be avoided since another
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site may inherit the prefix and they may end up using the same
multicast addresses.''
8.2. Mobility
o [RFC5887] suggested that, for Mobile IP, define a better mechanism
to handle change of home agent address while mobile is
disconnected.
9. Gap Summary
9.1. Managing Prefixes
None. (call for contributions)
9.2. Address configuration
o Host address configuration
- SLAAC and DHCPv6 address configuration co-existence
-Dynamic upsteam learning:
DHCP-configured host may want to learn about the upstream
availability of new prefixes or loss of prior prefixes
dynamically by deducing from periodic RA messages.
-DHCP/SLAAC conflict:
Prefixes in the two protocols' massages may be different,
which may be caused by serious network configuration error. A
diagnosis/report mechanism is needed here.
-SLAAC-configured hosts find DHCPv6 is in use:
RA messages contain a "Managed Configuration" flag to indicate
DHCPv6 is in use. But it is unspecified what behavior should
be taken when the host receives RA messages with "M" set to 1.
The gap of standard will cause ambiguous host behavior.
- DHCPv6 reconfigure bulk usage
Maybe it is too heavy for the server. So is it possible for
bulk renumbering? Is there any requirement?
- RA prefix lifetime limitation
If previous RemainingLifetime is longer than two hours, it is
impossible to reduce a prefix's lifetime less than two hours.
Is it a standard gap for renumbering?
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o Router address configuration
- Learning new prefixes
If the site is multihoming, the interior routers would need a
mechanism to learn which upstream providers and prefixes were
currently reachable (and valid).
- Restart after renumbering
Some routers cache IP addresses in some situations. So routers
might need to be restarted as a result of site renumbering.
- Router naming
Using domain names for routers is suitable in some scenarios
but has not been widely deployed. Whether it is not easy to
use or just suitable in few situations needs further
investigation.
o Static address configuration
Further work is needed.
9.3. Address relevant entries update
o DNS records update
- DNS update automation
Synchronization between host renumbering and the updating of
its DNS records is hard. Forward and reverse DNS entries
update may need to be combined together.
- DNS data structure optimization
Is the DNS data structure optimization as A6 record [RFC2874]
necessary for easing renumbering?
- DNS authority
DNS zones are out of the administrative control. Authority
collaboration is needed.
o In-host server address update
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Hosts also record addresses of servers such as DNS server
addresses, radius server address, etc. While renumbering, the
host must update the records if these server addresses changed.
o Filters
- Filters management
There is a gap of filter management to identify where and
which of the filters need to be updated during renumbering.
Manageable filter update may be also needed.
- Filter update automation operation
Automation update tool is valuable for renumbering, and there
may be requirement of protocol standardization to deliver of
facility the tools.
9.4. Renumbering event management
o Renumbering notification
If hosts/servers are aware of a renumbering event happening, it may
help the relevant process. A basic way is to extend current protocol
messages to carry the renumbering notification.
o Synchronization management
- DNS update synchronization
An example is synchronizing the SLAAC and DNS updates, and of
reducing the SLAAC lease time and DNS TTL.
[TBD]
o Renumbering monitoring
Mechanisms to monitor the process and feedback of renumbering may be
needed. [TBD]
10. Security Considerations
o Prefix Validation
Prefixes from the ISP may need authentication to prevent prefix
fraud. Announcing changes of site prefix to other sites (for example,
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those that configure routers or VPNs to point to the site in
question) also need validation.
In the LAN, Secure DHCPv6 ([I-D.ietf-dhc-secure-dhcpv6]) or SeND
([RFC3971], Secure Neighbor Discovery) deployment may need to
validate prefixes.
o Influence to Security Controls
During renumbering, security controls (e.g. ACLs) blocking access to
legitimate resources should not be interrupted.
11. IANA Considerations
None.
12. References
12.1. Normative References
[RFC2894] M. Crawford, "Router Renumbering for IPv6", RFC 2894,
August 2000.
[RFC2874] Crawford, M., and C. Huitema, "DNS Extensions to Support
IPv6 Address Aggregation and Renumbering", RFC 2874, July
2000.
[RFC3007] B. Wellington, "Secure Domain Name System (DNS) Dynamic
Update", RFC 3007, November 2000.
[RFC3315] R. Droms, Bound, J., Volz, B., Lemon, T., Perkins, C., 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.
[RFC3956] P. Savola, and B. Haberman. "Embedding the Rendezvous Point
(RP) Address in an IPv6 Multicast Address.", RFC 3956,
November 2004.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander
"SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005
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[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.
12.2. Informative References
[RFC2072] H. Berkowitz, "Router Renumbering Guide" RFC2072
[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
Renumbering an IPv6 Network without a Flag Day", RFC 4192,
September 2005.
[RFC5887] Carpenter, B., Atkinson, R., and H. Flinck, "Renumbering
Still Needs Work", RFC 5887, May 2010.
[I-D.ietf-dhc-secure-dhcpv6]
Jiang, S., and Shen S., "Secure DHCPv6 Using CGAs", working
in progress.
[I-D.chown-v6ops-renumber-thinkabout]
Chown, T., "Things to think about when Renumbering an IPv6
network", Work in Progress, September 2006.
[I-D.jiang-6renum-enterprise]
Jiang, S., and Liu B., " IPv6 Enterprise Network
Renumbering Scenarios and Guidelines ", Working in
Progress, July 2011.
[LEROY] Leroy, D. and O. Bonaventure, "Preparing network
configurations for IPv6 renumbering", International of
Network Management, 2009, <http://
inl.info.ucl.ac.be/system/files/dleroy-nem-2009.pdf>
13. Acknowledgments
This work adopts significant amounts of content from [RFC5887] and
[I-D.chown-v6ops-renumber-thinkabout], so thank for Brian Carpenter,
Randall Atkinson, Hannu Flinck, Tim Chown, Mark Thompson, Alan Ford,
and Stig Venaas. Some useful materials were provided by Oliver
Bonaventure and his student Damien Leroy, thanks for them, too.
Useful comments and contributions were made by George Wesley, and
others.
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Internet-Draft IPv6 Site Renumbering Gap Analysis July 2011
This document was prepared using 2-Word-v2.0.template.dot.
Authors' Addresses
Bing Liu
Huawei Technologies Co., Ltd
Huawei Building, No.3 Xinxi Rd.,
Shang-Di Information Industry Base, Hai-Dian District, Beijing
P.R. China
Email: leo.liubing@huawei.com
Sheng Jiang
Huawei Technologies Co., Ltd
Huawei Building, No.3 Xinxi Rd.,
Shang-Di Information Industry Base, Hai-Dian District, Beijing
P.R. China
Email: jiangsheng@huawei.com
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