Internet Engineering Task Force (IETF) B. Carpenter
Request for Comments: 6036 Univ. of Auckland
Category: Informational S. Jiang
ISSN: 2070-1721 Huawei Technologies Co., Ltd
October 2010 Emerging Service Provider Scenarios for IPv6 Deployment
This document describes practices and plans that are emerging among
Internet Service Providers for the deployment of IPv6 services. They
are based on practical experience so far, as well as current plans
and requirements, reported in a survey of a number of ISPs carried
out in early 2010. This document identifies a number of technology
gaps, but it does not make recommendations.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................22. Survey of ISP's Experience, Plans, and Requirements .............42.1. Methodology ................................................42.2. General Questions about IP Service .........................42.3. Requirements for IPv6 Service ..............................52.4. Status and Plans for IPv6 Service ..........................52.5. IPv6 Technologies ..........................................52.6. Effect of Size .............................................63. Lessons from Experience and Planning ............................74. Gap Analysis ....................................................84.1. Product Issues .............................................84.2. Protocol Issues ............................................94.3. Documentation and General Issues ..........................105. Security Considerations ........................................116. Acknowledgements ...............................................117. Informative References .........................................12Appendix A. Summary of Replies ....................................14Appendix B. Questionnaire .........................................191. Introduction
As is well known, the approaching exhaustion of IPv4 address space
will bring about a situation in which Internet Service Providers
(ISPs) are faced with a choice between one or more of three major
1. Squeeze the use of IPv4 addresses even harder than today, using
smaller and smaller address blocks per enterprise customer, and
possibly trading address blocks with other ISPs.
2. Install multiple layers of Network Address Translation (NAT)
[CGN] or share IPv4 addresses by other methods such as address-
plus-port mapping [APLUSP], [PRANGE].
3. Deploy IPv6 and operate IPv4-IPv6 coexistence and interworking
This document focuses on alternative (3), while recognizing that many
ISPs may be obliged by circumstances to prolong the life of IPv4 by
using (1) or (2) while preparing for (3).
This document describes IPv6 deployment scenarios already adopted or
currently planned by a set of ISPs who responded to a technical
questionnaire. Thus, it is a factual record of the responses from
those ISPs. It makes no recommendations; the best choice of
scenarios will depend on the circumstances of individual ISPs.
We consider various aspects of IPv6 deployment: addressing, routing,
DNS, management, and IPv4-IPv6 coexistence and interworking. We do
not consider application services in detail, but we do cover general
The reader is assumed to be familiar with IPv6. The IETF's view of
core IPv6 requirements is to be found in [RFC4294] (currently being
updated as [NODEREQ]). However, this does not give a complete view
of mechanisms an ISP may need to deploy, since it considers the
requirements for an individual node, not for a network or service
infrastructure as a whole.
[RFC4029] discusses scenarios for introducing IPv6 into ISP networks,
as the problem was viewed some years ago. Its end goal is simply a
dual-stack ISP backbone. Today's view is that this is insufficient,
as it does not allow for interworking between IPv6-only and legacy
(IPv4-only) hosts. Indeed, the end goal today might be an IPv6-only
ISP backbone, with some form of legacy IPv4 support.
[RFC4779] discusses deployment in broadband access networks such as
Cable Television (CATV), Asymmetric Digital Subscriber Line (ADSL),
and wireless. [RFC5181], [RFC5121], and [RFC5692] deal specifically
with IEEE 802.16 access networks. MPLS-based ISPs may use the IPv6
Provider Edge Router (6PE) [RFC4798] mechanism.
[RFC4942] covers IPv6 security issues, especially those that are
specific to transition and IPv4-IPv6 coexistence scenarios.
[RFC4864] discusses "Local Network Protection", i.e., how the
internal structure of an IPv6 site network can be protected. This
affects how well an ISP's customers are protected after they deploy
Although the basic IPv6 standards have long been stable, it should be
noted that considerable work continues in the IETF, particularly to
resolve the issue of highly scalable multihoming support for IPv6
sites, and to resolve the problem of IP layer interworking between
IPv6-only and IPv4-only hosts. IPv6/IPv4 interworking at the
application layers is handled within the original dual-stack model of
IPv6 deployment: either one end of an application session will have
dual-stack connectivity, or a dual-stack intermediary such as an HTTP
proxy or SMTP server will interface to both IPv4-only and IPv6-only
hosts or applications.
[RFC5211] describes an independent view of a possible sequence of
events for IPv6 adoption in the Internet as a whole, with direct
implications for ISPs. Its main point, perhaps, is that by the year
2012, it will be appropriate to regard IPv4 networks as the legacy
2. Survey of ISP's Experience, Plans, and Requirements
To obtain a view of the IPv6 experience, plans, and requirements of
ISPs, a questionnaire was issued by the authors in December 2009 and
announced widely to the operational community. We promised to keep
the replies strictly confidential and to publish only combined
results, without identifying information about individual ISPs in any
published results. The raw technical questions are shown in
Appendix B, and a detailed summary of the replies is in Appendix A.
Note that although the questionnaire was widely announced, those who
chose to reply were self-selected and we can make no claim of
statistical significance or freedom from bias in the results. In
particular, we assume that ISPs with a pre-existing interest in IPv6
are more likely to have replied than others. The results should
therefore be interpreted with some care.
2.2. General Questions about IP Service
Thirty-one ISPs replied before the cutoff date for this analysis. 65%
of responses were from European ISPs but large operators in North
America and Asian/Pacific regions are included. Commercial ISPs
operating nationally predominate, with a vast range of size (from 30
customers up to 40 million). Note that some providers chose not to
answer about the exact number of customers. Nevertheless, it can be
stated that 6 providers each had millions of customers, the next 10
each had more than 10,000 customers, and the remaining 15 each had
fewer than 10,000 customers.
80% of the respondents offer both transit and origin-only service;
29% offer IP multicast service; 80% have multihomed customers.
A very wide variety of access technologies is used: xDSL, Data Over
Cable Service Interface Specification (DOCSIS), leased line (X.25,
Time Division Multiplexer / Plesiochronous Digital Hierarchy (TDM/
PDH), Synchronous Digital Hierarchy (SDH)), ATM, frame relay, dialup,
microwave, Fiber To The Premises (FTTP), CDMA, Universal Mobile
Telecommunications System (UMTS), Long Term Evolution (LTE),
Worldwide Interoperability for Microwave Access (WiMAX), Broadband
Wireless Access (BWA), WiFi, Ethernet (100M-10G), Ethernet/SDH,
MetroEthernet/MPLS. Most ISPs provide Customer Premises Equipment
(CPE) to some or all of their customers, but these CPE are often
unable to support IPv6.
Estimates of when ISPs will run out of public IPv4 address space for
internal use vary widely, between "now" and "never". Public IPv4
address space for customers is mainly expected to run out between
2010 and 2015, but four or five ISPs suggested it will never happen,
or at least not in the foreseeable future. About 19% of ISPs offer
RFC 1918 space to customers, and about 39% use such addresses
2.3. Requirements for IPv6 Service
61% of ISPs report that some big customers are requesting IPv6.
Predictions for when 10% of customers will require IPv6 range from
2010 to 2017, and for 50% from 2011 to 2020. These ISPs require IPv6
to be a standard service by 2010 to 2015; the most common target date
2.4. Status and Plans for IPv6 Service
42% of ISPs already offer IPv6 as a regular service, although, in
general, it is used by fewer than 1% of customers. Another 48% of
ISPs have IPv6 deployment in progress or planned. These all plan at
least beta-test service in 2010. Planned dates for regular service
are between 2010 and 2013 (except for one ISP who replied that it
depends on the marketing department). When asked when IPv6 will
reach 50% of total traffic, the most common answer is 2015.
2.5. IPv6 Technologies
Turning to technology choices, the overwhelming choice of approach
(94%) is a dual-stack routing backbone, and the reason given is
simplicity and cost. 39% run, or plan to run, a 6to4 relay as well,
and 16% run or plan a Teredo server. However, 77% of ISPs don't have
or plan to have any devices dedicated to IPv6. A different 77% don't
see IPv6 as an opportunity to restructure their network topology.
When asked which types of equipment are unable to support IPv6, the
most common answer was CPE (10 mentions). Also mentioned: handsets;
Digital Subscriber Line Access Multiplexers (DSLAMs); routers
(including several specific models); traffic management boxes; load
balancers; VPN boxes; some SIP platforms; management interfaces &
systems; firewalls; billing systems. When asked if such devices can
be field-upgraded, the answers were gloomy: 5 yes, 4 partially, 10
no, and numerous "don't know" or "hopefully".
84% support or plan DNS Authentication, Authorization, Accounting,
and Auditing (AAAA) queries over IPv6, and all but one of these
include reverse DNS lookup for IPv6.
The ISPs surveyed have prefixes ranging from /19 to /48, and have a
variety of policies for customer prefixes. Fifteen ISPs offer more
than one of /48, /52, /56, /60, or /64. Two offer /56 only, eight
offer /48 only. Two wired operators offer /64 only. Mobile
operators offer /64 in accordance with 3GPP, but at least one would
like to be allowed to offer /128 or /126. Also, as many as 30% of
the operators already have IPv6 customers preferring a PI (provider
independent) prefix. The methods chosen for prefix delegation to
CPEs are manual, DHCPv6[-PD], Stateless Address Autoconfiguration
(SLAAC), RADIUS, and Point-to-Point Protocol over Ethernet (PPPoE).
However, in fact, the latter two cannot assign a prefix on their own.
About 50% of ISPs already operate or plan dual-stack SMTP, Post
Office Protocol 3 (POP3), IMAP, and HTTP services. In terms of
internal services, it seems that firewalls, intrusion detection,
address management, monitoring, and network management tools are also
around the 50% mark. However, accounting and billing software is
only ready at 23% of ISPs.
Considering IPv4-IPv6 interworking, 58% of ISPs don't expect to have
IPv6-only customers (but mobile operators are certain they will have
millions). Five ISPs report customers who explicitly refused to
consider IPv6. When asked how long customers will run IPv4-only
applications, the most frequent answer is "more than ten years".
Only three ISPs state that IPv6-IPv4 interworking at the IP layer is
not needed. On the other hand, only three (a different three!) run
or plan to run NAT-PT (Protocol Translation). At least 30% plan to
run some kind of translator (presumably NAT64/DNS64), but only two
felt that a multicast translator was essential. Among those who do
not plan a translator, when asked how they plan to connect IPv6-only
customers to IPv4-only services, seven rely on dual stack and four
have no plan (one said, paraphrasing, "it's their problem").
Asked about plans for Mobile IPv6 (or Nemo mobile networks), 19% said
yes, and 71% said no, with the others uncertain. A detailed analysis
shows that of the six ISPs who responded positively, three are large
mobile operators (and a fourth mobile operator said no). The other
three who responded positively were broadband ISPs ranging from small
to very large.
2.6. Effect of Size
We examined the data to see whether any other differences would
emerge between the very large (millions of customers), medium (at
least 10,000), and small (fewer than 10,000) operators. However, the
range of answers seems to be broadly similar in all cases. The major
exception is that among the six very large operators, one plans to
use 6PE and dual-stack lite (DS-lite), and another to use IPv6 on VPN
to Provider Edge Router (6VPE), instead of a simple dual stack. The
other large operators and all the medium and small operators prefer a
simple dual stack.
3. Lessons from Experience and Planning
This section is assembled and paraphrased from general comments made
in the various questionnaire responses. Any inconsistencies or
contradictions are present in the original data. Comments related to
missing features and products have been included in Section 4.
As noted in the summary above, the ISPs that responded overwhelmingly
prefer a native dual-stack deployment. Numerous comments mentioned
the simplicity of this model and the complexity and sub-optimal
routing of tunnel-based solutions. Topology redesign is not
generally considered desirable, because congruent IPv4 and IPv6
topology simplifies maintenance and engineering. Nevertheless, 6to4
is considered convenient for cable modem (DOCSIS) users and IPv6
Rapid Deployment (6RD) is considered an attractive model by some.
Various operators, but by no means all, also see a need for Teredo.
One very large MPLS-based operator prefers 6PE because it avoids an
IPv6 IGP and reduces operational costs. This operator also sees IPv4
scarcity addressed by DS-lite [DSLITE] and Carrier Grade NAT, also
acting as a catalyst for IPv6. Another very large operator with an
existing NAT44 infrastructure plans to use 6VPE [RFC4659] and
believes that NAT64 will be similar to NAT44 in support requirements.
Several ISPs observe that IPv6 deployment is technically not hard.
The most eloquent statement: "Just do it, bit by bit. It is very
much an 'eating the elephant' problem, but at one mouthful at a time,
it appears to be surprisingly easy." Other comments paraphrased from
the replies are:
o Despite the known gaps, the tools and toolkits are fairly mature
at this point.
o Managerial commitment and a systematic approach to analyzing
requirements and readiness are essential.
o Evangelization remains a must, as it seems that many ISP and IT
managers are still unaware of the need for an IPv6 plan, and are
inclined to dismiss IPv4 depletion as a false alarm, and also seem
unaware that NATs create expensive support requirements.
o Without customers wanting IPv6, getting business backing is very
hard, and IPv6 security and scale was not a focus for vendors
until very recently.
o Operators lack real experience with customer usage of IPv6, and
the resulting lack of confidence causes delay.
Three further quotations are of interest:
"We are planning to move all our management addressing from IPv4 to
IPv6 to free up IPv4 addresses."
"I am actively pushing our larger customers to start testing IPv6 as
our development has pretty much stopped as we need some real world
testing to be done."
"Customer support needs to be aware that IPv6 is being started in
your network, or servers. We experienced many IPv6 blocking
applications, applications that do not fall back to IPv4, etc. The
most difficult part may be to get engineers, sales, customer support
personnel to like IPv6."
4. Gap Analysis
The survey has shown a certain number of desirable features to be
missing, either in relevant specifications, or in many products.
This section summarizes those gaps.
4.1. Product Issues
As noted above, numerous models of various types of product still do
not support IPv6:
o Traffic management boxes
o Load balancers
o VPN boxes
o SIP and other appliances
o Management interfaces and systems
o Even where they support IPv6, customer-side firewalls and routers
need to operate at 25-100 Mbit/s
o Intrusion detection systems
o Accounting and billing systems
It is not the purpose of this document to name and shame vendors, but
today it is becoming urgent for all products to avoid becoming part
of the IPv4 legacy. ISPs stated that they want consistent feature-
equivalent support for IPv4 and IPv6 in all equipment and software at
reasonable or no extra cost. The problems can be quite subtle: for
example, one CPE with "full" IPv6 support does not support IPv6
traffic shaping, so the ISP cannot cap IPv6 traffic to contractual
Numerous ISPs want a scalable NAT64/DNS64 product.
The need for IPv6 support in "all the best open source tools" was
Several ISPs also noted that much commercial applications software
does not correctly support IPv6 and that this will cause customer
problems. Also, some operating systems are still shipped with IPv6
disabled by default or with features such as IPv4-mapped addresses
disabled by default.
4.2. Protocol Issues
Various needs and issues related mainly to protocols were mentioned:
o A specific CPE need is an intelligent prefix sub-delegation
mechanism (ease of use issue).
o "Getting it right" so that a dual-stack client doesn't end up
trying to use the wrong transport to reach a site.
o "User-side port allocation mechanisms. UPnP IGD and NAT-PMP can
be used for IPv4, but nothing exists for IPv6 (yet)." UPnP IGD
refers to the Universal Plug and Play Forum's Internet Gateway
Device. NAT-PMP is the NAT Port Mapping Protocol.
Editor's comment: even though port mapping is in principle
unnecessary for IPv6, a method of opening ports through
firewalls on demand seems necessary.
o Full Router Advertisement (RA) support on LAN side of ADSL CPE.
o PPPoE and RADIUS support. Specifically, global unicast address
assignment for Layer 2 Tunneling Protocol (L2TP) / PPPoE.
Currently, the PPPoE client will be assigned a link-local address,
requiring a second step (DHCPv6 or SLAAC).
o Simple automatic distribution of DNS server details is essential;
a DNS server option in RA [RFC5006] is wanted.
o ISPs need fully featured DHCPv6, especially since SLAAC does not
allow settings to be pushed out (except for RFC 5006).
o Firewall systems should not use separate IPv4 and IPv6 rules.
o Gaps in infrastructure security for IPv6 management.
o Gaps in routers' treatment of header options.
o RA-Guard in switches.
o Virtual Router Redundancy Protocol (VRRP) support.
o PE-CE routing protocols (OSPF and IS-IS).
o Problems using a single BGP session to exchange routes for both
IPv4 and IPv6.
o Consistent IPv6 address display format in outputs and
configuration input. Inconsistency breaks a lot of existing
4.3. Documentation and General Issues
We also note areas where there was clearly confusion among the ISPs
responding, which may denote weaknesses of existing documentation:
o Perhaps due to poor phrasing in the survey questions, some ISPs
indicated that they would use PPPoE or RADIUS to assign prefixes
to CPEs. In fact, IPv6 PPP only negotiates 64-bit interface
identifiers; a full address has to be assigned by another method,
and even this does not delegate a prefix to a CPE router. RADIUS
alone is also insufficient, as it needs to be combined with
another method for full address assignment.
o Although most ISPs see a need for IPv4-IPv6 interworking at the
network layer, many of them do not see a need for an ISP to
operate the resulting translator. Yet, their customers, whether
subscribers or content providers, will be the first to suffer when
IPv6-only clients cannot reach IPv4-only services.
o Most ISPs seemed to misunderstand the nature of a tunnel broker,
even though this is a service that any ISP could consider offering
to its subscribers.
Global IPv6 connectivity still has issues; for example, ISPs in the
Pacific region may have to obtain IPv6 transit via the USA (a
situation faced by IPv4 operators in Europe about twenty years ago).
Also, there are persistent Path MTU Discovery (PMTUD) issues in
various places on the net, and a lack of multicast peering.
Finally, there was a comment that real deployment case studies must
be shown to operators along with multihoming and traffic engineering
5. Security Considerations
As a report on a survey, this document creates no security issues in
itself. ISPs did not register any general concerns about IPv6
security. However, we note that about half of all firewall and
intrusion detection products are still reported not to support IPv6.
Some ISPs expressed concern about firewall performance and about the
need for separate firewall configurations for IPv4 and IPv6.
We are grateful to all those who answered the questionnaire: Stewart
Bamford, Pete Barnwell, Cameron Byrne, Gareth Campling, Kevin
Epperson, David Freedman, Wesley George, Steinar Haug, Paul
Hoogsteder, Mario Iseli, Christian Jacquenet, Kurt Jaeger, Seiichi
Kawamura, Adrian Kennard, Simon Leinen, Riccardo Loselli, Janos
Mohacsi, Jon Morby, Michael Newbery, Barry O'Donovan, Al Pooley,
Antonio Querubin, Anthony Ryan, Marc Schaeffer, Valeriu Vraciu, Bill
Walker, and those who preferred to remain anonymous.
The ISPs willing to be named were: AISP, Alphanet, Breedband Delft,
Claranet, E4A, Fidonet, Finecom, France Telecom, Hungarnet, Imagine,
LavaNet, Level 3 Communications LLC, NEC BIGLOBE, Nepustilnet, Net
North West, RoEduNet, SWITCH, Snap, Sprint, Star Technology, T-Mobile
USA, Ventelo, and Whole Ltd.
Useful comments and contributions were also made by Shane Amante,
Mohamed Boucadair, Mark Smith, and others.
This document was produced using the xml2rfc tool [RFC2629].
7. Informative References
[APLUSP] Bush, R., "The A+P Approach to the IPv4 Address Shortage",
Work in Progress, October 2009.
[CGN] Yamagata, I., Miyakawa, S., Nakagawa, A., and H. Ashida,
"Common requirements for IP address sharing schemes", Work
in Progress, July 2010.
[DSLITE] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", Work in Progress, August 2010.
[NODEREQ] Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node
Requirements RFC 4294-bis", Work in Progress, July 2010.
[PRANGE] Boucadair, M., Levis, P., Bajko, G., and T. Savolainen,
"IPv4 Connectivity Access in the Context of IPv4 Address
Exhaustion: Port Range based IP Architecture", Work
in Progress, July 2009.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
[RFC4029] Lind, M., Ksinant, V., Park, S., Baudot, A., and P.
Savola, "Scenarios and Analysis for Introducing IPv6 into
ISP Networks", RFC 4029, March 2005.
[RFC4294] Loughney, J., "IPv6 Node Requirements", RFC 4294,
[RFC4659] De Clercq, J., Ooms, D., Carugi, M., and F. Le Faucheur,
"BGP-MPLS IP Virtual Private Network (VPN) Extension for
IPv6 VPN", RFC 4659, September 2006.
[RFC4779] Asadullah, S., Ahmed, A., Popoviciu, C., Savola, P., and
J. Palet, "ISP IPv6 Deployment Scenarios in Broadband
Access Networks", RFC 4779, January 2007.
[RFC4798] De Clercq, J., Ooms, D., Prevost, S., and F. Le Faucheur,
"Connecting IPv6 Islands over IPv4 MPLS Using IPv6
Provider Edge Routers (6PE)", RFC 4798, February 2007.
[RFC4864] Van de Velde, G., Hain, T., Droms, R., Carpenter, B., and
E. Klein, "Local Network Protection for IPv6", RFC 4864,
[RFC4942] Davies, E., Krishnan, S., and P. Savola, "IPv6 Transition/
Co-existence Security Considerations", RFC 4942,
[RFC5006] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
"IPv6 Router Advertisement Option for DNS Configuration",
RFC 5006, September 2007.
[RFC5121] Patil, B., Xia, F., Sarikaya, B., Choi, JH., and S.
Madanapalli, "Transmission of IPv6 via the IPv6
Convergence Sublayer over IEEE 802.16 Networks", RFC 5121,
[RFC5181] Shin, M-K., Han, Y-H., Kim, S-E., and D. Premec, "IPv6
Deployment Scenarios in 802.16 Networks", RFC 5181,
[RFC5211] Curran, J., "An Internet Transition Plan", RFC 5211,
[RFC5692] Jeon, H., Jeong, S., and M. Riegel, "Transmission of IP
over Ethernet over IEEE 802.16 Networks", RFC 5692,
Appendix A. Summary of Replies
This summarizes the 31 replies received by April 14, 2010. Note that
the answers to some questions do not total to 31, due to missing
answers or to multiple choices in some cases. The ISPs are
distributed as follows:
North America: 7
They can additionally be classified as:
Operating internationally: 6
Operating nationally: 25
Basic data about IP service offerings:
o Offering both origin-only and transit service: 25
o Offering no transit: 6
o Number of private/small office customers (one IPv4 address): a few
with zero, then from 30 units up to 40 million
o Number of corporate customers (block of IPv4 addresses): a few
with zero, then from 40 units up to 40000
o IP multicast service? 9 yes, 22 no
o Do any customers require multihoming to multiple ISPs? 25 yes, 6
o Access technologies used: xDSL, DOCSIS, leased line (X.25, TDM/
PDH, SDH), ATM, frame relay, dialup, microwave, FTTP, CDMA, UMTS,
LTE, WiMAX, BWA, WiFi, Ethernet (100M-10G), Ether/SONET, Ether/
MPLS, IPv6-in-IPv4 tunnels.
Customer Premises Equipment:
o Do customers use CPE that ISP supplies? 27 yes (10% to 100% of
customers), 4 no
o Does the CPE provided support native IPv6? 17 yes (some), 10 no
o (Note that these numbers include answers that apply to tens of
millions of mobile handsets.)
IPv4 Address Space:
o When do you expect to run out of public IPv4 address space inside
your own network? Estimates run from "now" to 2020, but 5 ISPs
say "never" or "unforeseeable".
o Do you run RFC1918 addresses and NAT within your network? 9 yes;
18 no; 3 others say yes, but only for equipment management or
o What % of IPv4 space is needed for ISP use (not for customers)? 1%
to 30% (and 100% for NRENs with PI customers).
o When do you expect to run out of public IPv4 address space for
customers? Answers range from 2010 to 2015; 4 ISPs say it depends
on their registry. 4 or 5 give answers suggesting it will never
o Do you offer RFC1918 addresses to customers? 6 yes, 24 no
o Are some big customers requesting IPv6? 19 yes, 12 no
o When do you predict 10% and 50% of customers to require IPv6
service? Ignoring unclear answers, answers for 10% range from
2010 to 2017, and for 50% from 2011 to 2020.
o When do you require IPv6 to be a standard service available to all
customers? Answers range from 2010 to 2015; the most common
answer is 2011.
o When do you predict IPv6 traffic to reach 50% of total traffic?
Answers range from 2011 to 2020; the most common answer is 2015.
IPv6 Status and Plans:
o Do you currently offer IPv6 as a regular service? 13 yes, 5
partial, 12 no
o What % of customers currently use IPv6? <1% to 30%; mostly 0 or
o When do you plan to start IPv6 deployment? 12 complete, 12 in
progress, 3 in plan, 4 have no plan
o When do you plan to offer IPv6 as a special or beta-test service?
For all those in progress or with a plan, the answer was either
"now" or during 2010.
o When do you plan to offer IPv6 as a regular service to all
customers? For all those in progress or with a plan, the answer
was between "now" and 2013 (except for one ISP who replied that it
depends on the marketing department).
IPv6 Technologies. Note the answers refer to actual deployment or to
plans, as the case may be:
o Which basic IPv6 access method(s) apply?
* Dual-stack routing backbone: 29 yes, 1 maybe
* Separate IPv4 and IPv6 backbones: 2 yes, 1 maybe
* 6to4 relay: 12 yes
* Teredo server: 5 yes
* Tunnel broker: Unfortunately this question was unclear and
obviously misunderstood by most respondents. Several
respondents mentioned that they are getting their own transit
connectivity via static tunnels.
* Something else: Answers were 6VPE + NAT64/DNS64; PNAT;
o Please briefly explain the main reasons/issues behind your choice:
The best summary of the answers is "dual stack is simplest, why do
o Which types of equipment in your network are unable to support
IPv6? The most common answer was CPE (9 mentions). Also
mentioned: handsets; DSLAMs; routers (including several specific
models); traffic management boxes; load balancers; VPN boxes; some
SIP platforms; management interfaces & systems; firewalls; billing
o Can they be field-upgraded? 5 yes, 4 partially, 10 no and numerous
"don't know" or "hopefully"
o Is any equipment 100% dedicated to IPv6? 7 yes, 24 no
o Is IPv6 an opportunity to restructure your whole topology? 2 yes,
5 partial, 23 no
o Do you include support for DNS AAAA queries over IPv6? 21 yes, 5
plan, 4 no
o Do you include support for reverse DNS for IPv6 addresses? 22 yes,
3 plan, 5 no
o What length(s) of IPv6 prefix do you have or need from the
registry? 1 /19, 1 /21 (plus several /32s), 1 /22 1 /30, 3
multiple /32s, 21 /32, 3 /48
o What length(s) of IPv6 prefix are offered to customers? 15 ISPs
offer more than one of /48, /52, /56, /60 or /64. 2 offer /56
only, 8 offer /48 only. Two wired operators offer /64 only.
Mobile operators offer /64 in accordance with 3GPP, but at least
one would like to be allowed to offer /128 or /126.
o Do any customers share their IPv6 prefix among multiple hosts?
Unfortunately this question was unclear and obviously
misunderstood by most respondents.
o Do any of your customers prefer to use PI IPv6 prefixes? 10 yes,
o How are IPv6 prefixes delegated to CPEs? 16 manual, 10
DHCPv6[-PD], 8 SLAAC, 8 RADIUS, 2 PPPoE. (Note: RADIUS and PPP
cannot in fact delegate prefixes.)
o Are your SMTP, POP3 and IMAP services dual stack? 10 yes, 6 plan,
o Are your HTTP services, including caching and webmail, dual-stack?
9 yes, 1 partial, 4 plan, 15 no
o Are any other services dual stack? 11 yes, 2 plan, 11 no
o Is each of the following dual stack?
* Firewalls: 12 yes, 3 partial, 3 plan, 9 no
* Intrusion detection: 10 yes, 2 plan, 13 no
* Address management software: 15 yes, 1 plan, 13 no
* Accounting software: 7 yes, 21 no
* Monitoring software: 16 yes, 2 partial, 2 plan, 11 no
* Network management tools: 13 yes, 4 partial, 1 plan, 11 no
o Do you or will you have IPv6-only customers? 13 yes (or maybe), 18
no (or not likely)
o Do you have customers who have explicitly refused to consider
IPv6? 5 yes, 23 no
o Interworking issues:
* How many years do you expect customers to run any IPv4-only
applications? Answers range from 2 years to infinity, most
frequent answer is >10 years.
* Is IPv6-IPv4 interworking at the IP layer needed? 16 yes, 9
uncertain, 3 no
* Do you include a NAT-PT IPv6/IPv4 translator? 2 yes, 1 plan, 26
* If yes, does that include DNS translation? 1 plan, 2 no
* If not, do you plan to operate an IPv6/IPv4 translator? 10 plan
(NAT64), 8 no, others uncertain
* If not, how do you plan to connect IPv6-only customers to IPv4-
only services? 7 rely on dual stack; 4 have no plan (one said
* If you offer IP multicast, will that need to be translated too?
2 yes, 2 uncertain, 5 no
o Any plans for Mobile IPv6 (or Nemo mobile networks)? 6 yes, 2
uncertain, 22 no
Appendix B. Questionnaire
This appendix reproduces the technical body of the questionnaire that
was made available for ISPs to express their requirements, plans, and
I. General questions about IP service
1. Do you offer origin-only (stub, end-user) IP service, transit IP
service, or both?
2. Approximate number of private/small office customers (one IPv4
3. Approximate number of corporate customers (block of IPv4
addresses, not included in Q2)
4. Do you offer IP multicast service?
5. Do any of your customers require multihoming to multiple ISPs?
6. Access technologies used (ADSL,etc.)
7. Do your customers use CPE that you supply?
7.1. What % of customers?
7.2. Does the CPE that you provide support native IPv6?
8. When do you expect to run out of public IPv4 address space inside
your own network?
8.1. Do you run private (RFC1918) addresses and NAT within your
network (i.e., a second layer of NAT in the case of customers
with their own NAT)?
8.2. What % of your IPv4 space is needed for your own use (not
9. When do you expect to run out of public IPv4 address space for
9.1. Do you offer private (RFC1918) addresses to your customers?
II. Questions about requirements for IPv6 service
10. Are some big customers requesting IPv6?
11. When do you predict 10% and 50% of your customers to require
12. When do you require IPv6 to be a standard service available to
13. When do you predict IPv6 traffic to reach 50% of total traffic?
III. Questions about status and plans for IPv6 service
14. Do you currently offer IPv6 as a regular service?
14.1. What % of your customers currently use IPv6?
14.2. When do you plan to start IPv6 deployment?
14.3. When do you plan to offer IPv6 as a special or beta-test
service to customers?
15. When do you plan to offer IPv6 as a regular service to all
IV. Questions about IPv6 technologies
16. Which basic IPv6 access method(s) apply:
16.1. dual stack routing backbone?
16.2. separate IPv4 and IPv6 backbones?
16.3. 6to4 relay?
16.4. Teredo server?
16.5. tunnel broker? If so, which one?
16.6. Something else? Please briefly describe your method:
16.7. If possible, please briefly explain the main reasons/
issues behind your choice.
17. Which types of equipment in your network are unable to support
17.1. Can they be field-upgraded to support IPv6?
17.2. Is any equipment 100% dedicated to IPv6?
18. Is IPv6 an opportunity to restructure your whole topology?
19. Do you include support for DNS AAAA queries over IPv6?
20. Do you include support for reverse DNS for IPv6 addresses?
21. What length(s) of IPv6 prefix do you have or need from the
22. What length(s) of IPv6 prefix are offered to customers?
22.1. Do any customers share their IPv6 prefix among multiple
23. Do any of your customers prefer to use PI IPv6 prefixes instead
of a prefix from you?
24. How are IPv6 prefixes delegated to CPEs? (Manual, PPPoE,
RADIUS, DHCPv6, stateless autoconfiguration/RA, etc...)
25. Are your SMTP, POP3 and IMAP services dual-stack?
26. Are your HTTP services, including caching and webmail, dual-
27. Are any other services dual-stack?
28. Is each of the following dual-stack?
28.2. Intrusion detection
28.3. Address management software
28.4. Accounting software
28.5. Monitoring software
28.6. Network management tools
29. Do you or will you have IPv6-only customers?
30. Do you have customers who have explicitly refused to consider
31. How many years do you expect customers to run any IPv4-only
32. Is IPv6-IPv4 interworking at the IP layer needed?
33. Do you include a NAT-PT IPv6/IPv4 translator?
33.1. If yes, does that include DNS translation?
33.2. If not, do you plan to operate an IPv6/IPv4 translator?
33.3. If not, how do you plan to connect IPv6-only customers to
33.4. If you offer IP multicast, will that need to be
34. Any plans for Mobile IPv6 (or Nemo mobile networks)?
35. What features and tools are missing today for IPv6 deployment
36. Any other comments about your IPv6 experience or plans? What
went well, what was difficult, etc.
Department of Computer Science
University of Auckland
Huawei Technologies Co., Ltd
KuiKe Building, No.9 Xinxi Rd.,
Shang-Di Information Industry Base, Hai-Dian District, Beijing