V6OPS G. Fioccola
Internet-Draft P. Volpato
Obsoletes: 6036 (if approved) Huawei Technologies
Intended status: Informational N. Elkins
Expires: January 30, 2023 Inside Products
J. Palet Martinez
The IPv6 Company
G. Mishra
Verizon Inc.
C. Xie
China Telecom
July 29, 2022
IPv6 Deployment Status
draft-ietf-v6ops-ipv6-deployment-07
Abstract
This document provides an overview of IPv6 deployment status in early
2022. Specifically, it looks at the degree of adoption of IPv6 in
the industry, analyzes the remaining challenges and proposes further
investigations in areas where the industry has not yet taken a clear
and unified approach in the transition to IPv6. It obsoletes RFC
6036.
Status of This Memo
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Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. IPv6: The Global Picture . . . . . . . . . . . . . . . . . . 6
2.1. IPv4 Address Exhaustion . . . . . . . . . . . . . . . . . 6
2.1.1. IPv4 addresses per capita and IPv6 status . . . . . . 7
2.2. IPv6 Users . . . . . . . . . . . . . . . . . . . . . . . 9
2.3. IPv6 Web Content . . . . . . . . . . . . . . . . . . . . 10
2.4. IPv6 public actions and policies . . . . . . . . . . . . 10
3. A Survey on IPv6 Deployments . . . . . . . . . . . . . . . . 11
3.1. IPv6 Allocations . . . . . . . . . . . . . . . . . . . . 11
3.2. IPv6 among Internet Service Providers . . . . . . . . . . 13
3.3. IPv6 among Enterprises . . . . . . . . . . . . . . . . . 14
3.3.1. Government and Universities . . . . . . . . . . . . . 15
3.4. Observations on Industrial Internet . . . . . . . . . . . 17
3.5. Observations on Content and Cloud Service Providers . . . 17
3.6. Application Transition . . . . . . . . . . . . . . . . . 18
4. IPv6 deployment scenarios . . . . . . . . . . . . . . . . . . 18
4.1. Dual-Stack . . . . . . . . . . . . . . . . . . . . . . . 18
4.2. IPv4 as a Service and IPv6-only Overlay . . . . . . . . . 19
4.3. IPv6-only Underlay . . . . . . . . . . . . . . . . . . . 20
4.4. IPv6-only . . . . . . . . . . . . . . . . . . . . . . . . 21
5. Common IPv6 Challenges . . . . . . . . . . . . . . . . . . . 21
5.1. Transition Choices . . . . . . . . . . . . . . . . . . . 22
5.1.1. Service Providers . . . . . . . . . . . . . . . . . . 22
5.1.2. Enterprises and Industrial Internet . . . . . . . . . 23
5.1.3. Cloud and Data Centers . . . . . . . . . . . . . . . 24
5.1.4. CEs and user devices . . . . . . . . . . . . . . . . 24
5.2. Network Management and Operations . . . . . . . . . . . . 25
5.3. Performance . . . . . . . . . . . . . . . . . . . . . . . 26
5.3.1. IPv6 packet loss and latency . . . . . . . . . . . . 26
5.3.2. Customer Experience . . . . . . . . . . . . . . . . . 27
5.4. IPv6 security and privacy . . . . . . . . . . . . . . . . 27
5.4.1. Protocols security issues . . . . . . . . . . . . . . 28
5.4.2. IPv6 Extension Headers and Fragmentation . . . . . . 29
6. Security Considerations . . . . . . . . . . . . . . . . . . . 30
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 30
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8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 30
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
10.1. Normative References . . . . . . . . . . . . . . . . . . 30
10.2. Informative References . . . . . . . . . . . . . . . . . 32
Appendix A. Summary of Questionnaire and Replies for network
operators . . . . . . . . . . . . . . . . . . . . . 40
Appendix B. Summary of Questionnaire and Replies for enterprises 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43
1. Introduction
[RFC6036] described IPv6 deployment scenarios adopted or foreseen by
a number of Internet Service Providers (ISPs) who responded to a
technical questionnaire in early 2010. In doing that, [RFC6036]
provided practices and plans expected to take place in the following
years. Since the publication of [RFC6036], several other documents
have contributed to the IPv6 transition discussion in operational
environments. To name a few:
- [RFC6180] discussed IPv6 deployment models and transition
mechanisms, recommending those proven to be effective in
operational networks.
- [RFC6883] provided guidance and suggestions for Internet content
providers and Application Service Providers (ASPs).
- [RFC7381] introduced the guidelines of IPv6 deployment for
enterprises.
It is worth mentioning here also [RFC6540]. It recommended the
support of IPv6 to all IP-capable nodes. It was referenced in the
IAB Statement on IPv6 [IAB], which represented a major step in
driving the IETF as well as other Standard Developing Organizations
(SDOs) towards using IPv6 in their works.
In more recent times, organizations such as ETSI provided more
contributions to the use of IPv6 in operational environments,
targeting IPv6 in different industry segments. As a result,
[ETSI-IP6-WhitePaper], was published to provide an updated view on
the IPv6 best practices adopted so far, in particular in the ISP
domain.
Considering all of the above, and after more than ten years since the
publication of [RFC6036] it may be interesting to revisit where the
transition of the Internet to IPv6 currently stands, what major steps
have been accomplished and what is still missing. Some reasons
include:
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- In some areas, the lack of IPv4 addresses forced both carriers
and content providers to shift to IPv6 to support the introduction
of new applications, in particular in wireless networks.
- Some governmental actions took place to encourage or even
enforce the adoption of IPv6 in certain countries.
- Looking at the global adoption of IPv6, this seems to have
reached a threshold that justifies speaking of native, end-to-end
IPv6 connectivity at the IPv6 service layer.
This document intends to provide a survey of the status of IPv6
deployment and highlight both the achievements and remaining
obstacles in the transition to IPv6 networks (and its coexistence
with continued IPv4 services). The target is to give an updated view
of the practices and plans already described in [RFC6036], to
encourage further actions and more investigations in those areas that
are still under discussion, and to present the main incentives for
the adoption of IPv6. The expectation is that this process may help
to understand what is missing and how to improve the current IPv6
deployment strategies of internet service providers, enterprises,
content and cloud service providers.
The initial section of this document reports some data about the
status of IPv6. The exhaustion of IPv4 as well as the measured
adoption of IPv6 at the users' and the content's side will be
discussed. Comparing both IPv4 and IPv6, IPv6 has a higher growth
rate all the years. This testifies the momentum of IPv6.
The next section provides a survey of IPv6 deployments in different
environments, including ISPs, enterprises, cloud providers and
universities. Data from some well-known analytics will be discussed.
In addition, two independent polls among network operators and
enterprises will also be presented.
Then, a section on IPv6 deployment will describe the IPv6 transition
approaches for Mobile BroadBand (MBB), Fixed BroadBand (FBB) and
Enterprise services. At present, Dual-Stack (DS) is the most
deployed solution for IPv6 introduction, while 464XLAT and Dual-Stack
Lite (DS-Lite) seem the preferred ones for those players that have
already enabled IPv6-only overlay service delivery.
The last parts of the document will analyze the general challenges to
be solved in the IPv6 transition. Specific attention will be given
to operations, performance and security issues. It aims to highlight
some areas that still require improvement and some actions that the
industry might consider to accelerate adoption of IPv6.
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1.1. Terminology
This section defines the terminology regarding the usage of IPv6-only
expressions within this document. The term IPv6-only is defined in
relation to the specific scope it is referring to. In this regard,
it may happen that only part of a service, of a network or even part
of a node is in an IPv6-only scope and the rest is not. Below are
listed the most used terms in relation to the different scopes:
IPv6-only interface: It means that the interface of a node is
configured to forward only IPv6. This denotes that just part of
the node can be IPv6-only since the rest of the interfaces of the
same node may work with IPv4 as well. A Dual-Stack interface is
not an IPv6-only interface.
IPv6-only node: It means that the node uses only IPv6. All
interfaces of the host only have IPv6 addresses.
IPv6-only service: It is used if between the host's interface and
the interface of the content server, all packet headers of the
service session are IPv6.
IPv6-only overlay: It is used if between the end points of the
tunnels, all inner packet headers of the tunnels are IPv6. For
example, IPv6-only overlay in fixed network means that the
encapsulation is only IPv6 between the interfaces of the Provider
Edge (PE) nodes or between the WAN interface of the Customer Edge
(CE) node and the Broadband Network Gateway (BNG) facing interface
of CGN.
IPv6-only underlay: It is used if the data plane and control plane
are IPv6, but not necessarily management plane. For example,
IPv6-only underlay in fixed network means that the underlay
network protocol is only IPv6 between any Provider Edge (PE) nodes
but they can be Dual-Stack in overlay. SRv6 is an example of
IPv6-only underlay.
IPv6-only network: It is used if every node in this network is
IPv6-only. No IPv4 should exist in an IPv6-only network. In
particular, IPv6-only network's data plane, control plane, and
management plane must be IPv6. All PEs must be IPv6-only.
Therefore, if tunnels exist among PEs, both inner and outer
headers must be IPv6. For example, IPv6-only access network means
that every nodes in this access network must be IPv6-only and
similarly IPv6-only backbone network means that every nodes in
this backbone network must be IPv6-only.
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IPv4 as a Service (IPv4aaS): It means that IPv4 service support is
provided by means of transition mechanism, therefore there is a
combination of encapsulation/translation + IPv6-only overlay +
decapsulation/translation.
Note that IPv6-only definitions are also discussed in
[I-D.palet-v6ops-ipv6-only].
2. IPv6: The Global Picture
This section deals with some key questions related to IPv6 namely:
(1) the status of IPv4 exhaustion, often considered as one of the
triggers to switch to IPv6, (2) the number of IPv6 end users, a
primary measure to sense IPv6 adoption, (3) the percentage of
websites reachable over IPv6 and (4) a report on IPv6 public actions
and policies.
These parameters are monitored by the Regional internet Registries
(RIRs) and other institutions worldwide as they provide a first-order
indication on the adoption of IPv6.
2.1. IPv4 Address Exhaustion
According to [CAIR] there will be 29.3 billion networked devices by
2023, up from 18.4 billion in 2018. This poses the question on
whether the IPv4 address space can sustain such a number of
allocations and, consequently, if this may affect the process of its
exhaustion. The answer is not straightforward as many aspects have
to be considered.
On one hand, the RIRs are reporting scarcity of available and still
reserved addresses. Table 3 of [POTAROO1] shows that the available
pool of the five RIRs counts 5.2 million IPv4 addresses, while the
reserved pool includes another 12 million, for a total of "usable"
addresses equal to 17.3 million (-5.5% year over year, comparing 2021
against 2020). The same reference, in table 1, shows that the total
IPv4 allocated pool equals to 3.685 billion addresses (+0.027% year
over year). The ratio between the "usable" addresses and the total
allocated brings to 0.469% of remaining space (from 0.474% at the end
of 2020).
On the other, [POTAROO1] again highlights the role of both address
transfer and Network Address Translation (NAT) to counter the IPv4
exhaustion. The transfer of IPv4 addresses can be done under the
control or registration of a RIR or on the so-called grey market
where third parties operate to enable the buy/sell of IPv4 addresses.
In all cases, a set of IPv4 addresses is "transferred" to a different
holder that has the need to expand their address range. As an
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example, [IGP-GT] and [NRO] show the amount of transfers to recipient
organizations in the different regions. Cloud Service Providers
(CSPs) appear to be the most active in buying IPv4 addresses to
satisfy their need of providing IPv4 connectivity to their tenants.
NAT systems provide a means to absorb at least a portion of the
demand of public IPv4 addresses as they enable the use of private
addressing in internal networks while limiting the use of public
addresses on their WAN-facing side. Their actions cannot be
objected, but it has to be noted that architectural and operational
issues remain, especially in the case of NAT. Private address space
cannot provide adequate address span, especially for large
organizations, and the reuse of addresses may make the network more
complex. In addition, multiple levels of address translation may
coexist in a network, e.g. Carrier-Grade NAT [RFC6264] based on two
stages of translation. This comes with an economic and operational
burden, as discussed later in this document.
2.1.1. IPv4 addresses per capita and IPv6 status
The IPv4 addresses per capita ratio measures the quantity of IPv4
addresses allocated to a given country divided by the population of
that country. It is a theoretical ratio, anyhow it provides an
indication of the imbalanced distribution of the IPv4 addresses
worldwide. It clearly derives from the allocation of addresses made
in the early days of the Internet by the most advanced countries.
The sources for measuring the IPv4 addresses per capita ratio are the
allocations done by the RIRs and the statistics about the world
population. In this regard, [POTAROO2] provides distribution files.
The next table compares the IPv4 addresses per capita ratio of a
certain country with relative adoption of IPv6, expressed as the
number of IPv6 capable users in the considered country. The table is
ordered based on the IPv4 addresses per capita ratio.
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+------------------------+-----------------+-----------------+
|Country | IPv4 per capita| IPv6 deployment|
+------------------------+-----------------+-----------------+
|United States of America| 4.89| 47.1%|
+------------------------+-----------------+-----------------+
|Sweden | 2.97| 11.8%|
+------------------------+-----------------+-----------------+
|Netherlands | 2.93| 35.5%|
+------------------------+-----------------+-----------------+
|Switzerland | 2.75| 34.9%|
+------------------------+-----------------+-----------------+
|Republic of Korea | 2.19| 17.1%|
+------------------------+-----------------+-----------------+
|Australia | 1.91| 28.8%|
+------------------------+-----------------+-----------------+
|Canada | 1.85| 32.4%|
+------------------------+-----------------+-----------------+
|United Kingdom | 1.65| 33.2%|
+------------------------+-----------------+-----------------+
|Belgium | 1.62| 62.0%|
+------------------------+-----------------+-----------------+
|Japan | 1.50| 36.7%|
+------------------------+-----------------+-----------------+
|Germany | 1.48| 53.0%|
+------------------------+-----------------+-----------------+
|France | 1.27| 42.1%|
+------------------------+-----------------+-----------------+
|Austria | 1.24| 29.2%|
+------------------------+-----------------+-----------------+
|Italy | 0.91| 4.7%|
+------------------------+-----------------+-----------------+
|Spain | 0.69| 3.0%|
+------------------------+-----------------+-----------------+
|Poland | 0.55| 14.7%|
+------------------------+-----------------+-----------------+
|Brazil | 0.41| 38.7%|
+------------------------+-----------------+-----------------+
|Russian Federation | 0.31| 9.7%|
+------------------------+-----------------+-----------------+
|China (*) | 0.24| 60.1%|
+------------------------+-----------------+-----------------+
|India | 0.03| 76.9%|
+------------------------+-----------------+-----------------+
Figure 1: IPv4 per capita and IPv6 deployment
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(*) The IPv6 deployment information in China is derived from
[CN-IPv6].
It is clear that there is no direct correlation between low IPv4 per
capita and high IPv6 adoption. For example, countries like the
Russian Federation, Poland, Spain and Italy have lower IPv4 per
capita ratio than countries like the U.S.A, Germany, France, even if
their IPv6 adoption rate is also lower. Looking at the countries
with higher IPv6 adoption, this appears related to several factors in
addition to the lack of IPv4 addresses, including local regulation
and market-driven actions.
2.2. IPv6 Users
The count of the IPv6 users is the key parameter to get an immediate
understanding of the adoption of IPv6. Some organizations constantly
track the usage of IPv6 by aggregating data from several sources. As
an example, the Internet Society constantly monitors the volume of
IPv6 traffic for the networks that joined the WorldIPv6Launch
initiative [WIPv6L]. The measurement aggregates statistics from
organizations such as [Akm-stats] that provides data down to the
single network level measuring the number of hits to their content
delivery platform. For the scope of this document, we follow the
approach used by APNIC to quantify the adoption of IPv6 by means of a
script that runs on a user's device [CAIDA]. To give a rough
estimation of the relative growth of IPv6, the next table aggregates
the total number of estimated IPv6-capable users at January 2022, and
compares it against the total Internet users, as measured by
[POTAROO2].
+--------+--------+--------+--------+--------+--------+--------+
| | Jan | Jan | Jan | Jan | Jan | CAGR |
| | 2018 | 2019 | 2020 | 2021 | 2022 | |
+--------+--------+--------+--------+--------+--------+--------+
| IPv6 | 513.07| 574.02| 989.25|1,136.28|1,207.61| 23.9% |
+--------+--------+--------+--------+--------+--------+--------+
| World |3,410.27|3,470.36|4,065.00|4,091.62|4,093.69| 4.7% |
+--------+--------+--------+--------+--------+--------+--------+
| Ratio | 15.0%| 16.5%| 24.3%| 27.8%| 29.5%| 18.4% |
+--------+--------+--------+--------+--------+--------+--------+
Figure 2: IPv6-capable users against total (in millions)
Two figures appear: first, the IPv6 Internet population is growing
with a two-digits Compound Annual Growth Rate (CAGR), and second, the
ratio IPv6 over total is also growing steadily.
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2.3. IPv6 Web Content
[W3Tech] keeps track of the use of several technical components of
websites. The utilization of IPv6 for websites is shown in the next
table.
+------------+-------+-------+-------+-------+-------+------+
| Wolrdwide | Jan | Jan | Jan | Jan | Jan | CAGR |
| Websites | 2018 | 2019 | 2020 | 2021 | 2022 | |
+------------+-------+-------+-------+-------+-------+------+
|% of IPv6 | 11.4% | 13.3% | 15.0% | 17.5% | 20.6% | 15.9%|
+------------+-------+-------+-------+-------+-------+------+
Figure 3: Usage of IPv6 in websites
Looking at the growth rate, it may appear not particularly high. It
has to be noted, though, that not all websites are equal. The
largest content providers, which already support IPv6, generate a lot
more content than small websites. [Csc6lab] measured at the
beginning of January 2022 that out of the world top 500 sites ranked
by [Alx], 203 are IPv6-enabled (+3.6% from January 2021 to January
2022). If we consider that the big content providers (such as
Google, Facebook, Netflix) generate more than 50% of the total mobile
traffic [SNDVN], and in some cases even more up to 65% ([ISOC1]
[HxBld]), the percentage of content accessible over IPv6 is clearly
more relevant than the number of enabled IPv6 websites.
Related to that, a question that sometimes arises is whether the
content stored by content providers would be all accessible on IPv6
in the hypothetical case of a sudden IPv4 switch-off. Even if this
is pure speculation, the numbers above may bring to state that this
is likely the case. This would reinforce the common thought that, in
quantitative terms, most of content is accessible via IPv6.
2.4. IPv6 public actions and policies
As previously noted, the worldwide deployment of IPv6 is not uniform
[G_stats], [APNIC1]. It is worth noticing that, in some cases,
higher IPv6 adoption in a certain country has been achieved as a
consequence of actions taken by the local government through
regulation or incentive to the market. Looking at the European Union
area, countries such as Belgium, France and Germany are well ahead in
terms of IPv6 adoption. In the case of Belgium, the Belgian
Institute for Postal services and Telecommunications (BIPT) acted to
mediate an agreement between the local ISPs and the government to
limit the use of CGN systems and of public IPv4 addresses for lawful
investigations in 2012 [BIPT]. The agreement limited the use of one
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IPv4 address per 16 customers behind NAT. The economic burden
sustained by the ISPs for the unoptimized use of NAT induced the
shift to IPv6 and its increased adoption in the latest years. In
France, the National Regulator (Autorite de regulation des
communications electroniques, or Arcep) introduced an obligation for
the mobile carriers awarded with a license to use 5G frequencies
(3.4-3.8GHz) in Metropolitan France to be IPv6 compatible [ARCEP].
As stated, "the goal is to ensure that services are interoperable and
to remove obstacles to using services that are only available in
IPv6, as the number of devices in use continues to soar, and because
the RIPE NCC has run out of IPv4 addresses". A slow adoption of IPv6
could prevent new Internet services to widespread or create a barrier
to entry for newcomers to the market. "IPv6 can help to increase
competition in the telecom industry, and help to industrialize a
country for specific vertical sectors". Increased IPv6 adoption in
Germany depended on a mix of industry and public actions.
Specifically, the Federal Office for Information Technology (under
the Federal Ministry of the Interior) issued over the years a few
recommendations on the use of IPv6 in the German public
administration. The latest guideline in 2019 constitutes a high-
level roadmap for mandatory IPv6 introduction in the federal
administration networks [GFA]. In the United States, the Office of
Management and Budget is also calling for IPv6 adoption [US-FR],
[US-CIO]. These documents define a plan to have the 80% of the US
Federal IP-capable networks based on IPv6-only by the year 2025.
China is another example of government which is supporting a country-
wide IPv6 adoption [CN]. In India, the high adoption of IPv6 took
origin from the decision of Reliance Jio to move to IPv6 in their
networks [RelJio]. In addition, the Department of Telecommunications
(under the Ministry of Communications and Information Technology)
issued guidelines for the progressive adoption of IPv6 in public and
private networks. The latest one dates 2021 [IDT] and fosters
further moves to native IPv6 connection services.
3. A Survey on IPv6 Deployments
After discussing the count of the IPv6 users, it is useful to discuss
the status of IPv6 adoption in operational networks.
3.1. IPv6 Allocations
RIRs are responsible for allocating IPv6 address blocks to ISPs, LIRs
(Local Internet Registries) as well as enterprises or other
organizations. An ISP/LIR will use the allocated block to assign
addresses to their end users. The following table shows the amount
of individual allocations, per RIR, in the time period 2017-2021
[APNIC2].
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+---------+-------+-------+-------+-------+-------+---------+------+
| Registry| Dec | Dec | Dec | Dec | Dec |Cumulated| CAGR |
| | 2017 | 2018 | 2019 | 2020 | 2021 | | |
+---------+-------+-------+-------+-------+-------+---------+------+
| AFRINIC | 112 | 110 | 115 | 109 | 136 | 582 | 51% |
| APNIC | 1,369 | 1,474 | 1,484 | 1,498 | 1,392 | 7,217 | 52% |
| ARIN | 684 | 659 | 605 | 644 | 671 | 3,263 | 48% |
| LACNIC | 1,549 | 1,448 | 1,614 | 1,801 | 730 | 7,142 | 47% |
| RIPE NCC| 2,051 | 2,620 | 3,104 | 1,403 | 2,542 | 11,720 | 55% |
| | | | | | | | |
| Total | 5,765 | 6,311 | 6,922 | 5,455 | 5,471 | 29,924 | 51% |
+---------+-------+-------+-------+-------+-------+---------+------+
Figure 4: IPv6 allocations worldwide
Overall, the trend is positive, showing the steady progress of IPv6.
The decline of IPv6 allocations in 2020 and 2021 may be due to
COVID-19 pandemic. It also happens to IPv4 allocations.
[APNIC2] also compares the number of allocations for both address
families. The CAGR looks quite similar in 2021 but a little higher
for the IPv4 allocations in comparison to the IPv6 allocations (53.6%
versus 50.9%).
+--------+-------+-------+-------+-------+-------+----------+------+
| Address| Dec | Dec | Dec | Dec | Dec | Cumulated| CAGR |
| family | 2017 | 2018 | 2019 | 2020 | 2021 | | |
+--------+-------+-------+-------+-------+-------+----------+------+
| IPv6 | 5,765 | 6,311 | 6,922 | 5,455 | 5,471 | 29,924 | 50.9%|
| | | | | | | | |
| IPv4 | 8,091 | 9,707 |13,112 | 6,263 | 7,829 | 45,002 | 53.6%|
| | | | | | | | |
+--------+-------+-------+-------+-------+-------+----------+------+
Figure 5: Allocations per address family
The reason may be that the IPv4 allocations in 2021 include many
allocations of small address ranges (e.g. /24) [APNIC2]. On the
contrary, a single IPv6 allocation is large enough to cope with the
need of an operator for long period. After an operator receives an
IPv6 /30 or /32 allocation it is unlikely that a new request of
addresses is repeated in the short term. Hence the two CAGR values
in the table should not be compared directly as the weight of the
allocations is different.
The next table is based on [APNIC3], [APNIC4] and shows the
percentage of Autonomous Systems (AS) supporting IPv6 compared to the
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total ASes worldwide. The number of IPv6-capable ASes increased from
24.3% in January 2018 to 38.7% in January 2022. This equals to 18%
CAGR for IPv6-enabled networks. In comparison, the CAGR for the
total of IPv6 and IPv4 networks is just 5%.
+------------+-------+-------+-------+-------+-------+------+
| Advertised | Jan | Jan | Jan | Jan | Jan | CAGR |
| ASN | 2018 | 2019 | 2020 | 2021 | 2022 | |
+------------+-------+-------+-------+-------+-------+------+
|IPv6-capable| 14,500| 16,470| 18,650| 21,400| 28,140| 18% |
| | | | | | | |
| Total ASN | 59,700| 63,100| 66,800| 70,400| 72,800| 5% |
| | | | | | | |
| Ratio | 24.3% | 26.1% | 27.9% | 30.4% | 38.7% | |
+------------+-------+-------+-------+-------+-------+------+
Figure 6: Percentage of IPv6-capable ASes
The tables above provide an aggregated view of the allocations
dynamic. But the aggregated view does not tell us the split between
the different types of organizations. The next sections will zoom
into each specific area to highlight the relative status.
3.2. IPv6 among Internet Service Providers
As it was proposed at the time of [RFC6036], also in the case of this
document a survey was submitted to a group of service providers in
Europe (see Appendix A for the complete poll), to understand their
plans about IPv6 and their technical preferences towards its
adoption. Although such poll does not give an exhaustive view on the
IPv6 status, it provides some insights that are relevant to the
discussion.
The poll reveals that the majority of the ISPs interviewed has plans
concerning IPv6 (79%). Of them, 60% has already ongoing activities,
while 33% is expected to start activities in a 12-months time-frame.
The transition to IPv6 involves all business segments: mobile (63%),
fixed (63%), and enterprises (50%).
The reasons to move to IPv6 vary. Global IPv4 address depletion and
the run out of private address space recommended in [RFC1918] are
reported as the important drivers for IPv6 deployment (48%). In a
few cases, respondents cite the requirement of national IPv6 policies
and the launch of 5G as the reasons (13%). Enterprise customers
demand is also a reason to introduce IPv6 (13%).
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From a technical preference standpoint, Dual-Stack is the most
adopted solution, in both wireline (59%) and cellular networks (39%).
In wireline, the second most adopted mechanism is DS-Lite (19%). In
cellular networks, the second preference is 464XLAT (21%).
More details about the answers received can be found in Appendix A.
3.3. IPv6 among Enterprises
As described in [RFC7381], enterprises face different challenges than
ISPs. Publicly available reports show how the enterprise deployment
of IPv6 lags behind ISP deployment [cmpwr]. In this document, an
enterprise is a company that is not an ISP unless stated otherwise.
[NST_1] provides estimations on deployment status of IPv6 for 1070
domains such as example.com, example.net or example.org in the United
States as of January 2022. The measurement encompasses many
industries, including telecommunications, so the term "enterprises"
is a bit loose in this context. In any case, it provides a first
indication of IPv6 adoption in several US industry sectors. The
analysis tries to infer whether IPv6 is supported by looking from
"outside" a company's network. It takes into consideration the
support of IPv6 to external services such as Domain Name System
(DNS), mail and website. [BGR_1] has similar data for China. The
measurement considers 478 second or third level domains such as
example.cn. [CNLABS_1] provides the status for 104 measured domains
in India.
+--------------+----------+---------+---------+---------+
|Country | Domains | DNS | Mail | Website |
| | analyzed | | | |
+--------------+----------+---------+---------+---------+
|China | 478 | 74.7% | 0.0% | 19.7% |
| | | | | |
+--------------+----------+---------+---------+---------+
|India | 104 | 51.9% | 15.4% | 16.3% |
| | | | | |
+--------------+----------+---------+---------+---------+
|United States | 1070 | 66.8% | 21.2% | 6.3% |
|of America | | | | |
+--------------+----------+---------+---------+---------+
Figure 7: IPv6 support for external-facing services across
enterprises
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A poll submitted to a group of large enterprises in North America
(see Appendix B) shows that the operational issues are likely to be
more critical than for ISPs.
Looking at current implementations, almost one third has dual-stacked
networks, while 20% declares that portions of their networks are
IPv6-only. 35% of the enterprises are stuck at the training phase.
In no case is the network fully IPv6-based.
Speaking of training, the most critical needs are in the field of
IPv6 security and IPv6 troubleshooting (both highlighted by the two
thirds of respondents), followed by IPv6 fundamentals (57.41%).
Coming to implementation, the three areas of concern are IPv6
security (31.48%), training (27.78%), application conversion
(25.93%). Interestingly, 33.33% of respondents think that all three
areas are all simultaneously of concern.
The full poll is reported in Appendix B.
3.3.1. Government and Universities
This section focuses specifically on the IPv6 adoption of governments
and academia.
As far as governmental agencies are concerned, [NST_2] provides
analytics on the degree of IPv6 support for DNS, mail and websites
across 1283 second level domains associated with the US federal
agencies. These domains are in the form of example.gov or
example.fed. The script used by [NST_2] has also been employed to
measure the same analytics in other countries. For China [BGR_2] 52
third level domains provide statistics. For India [CNLABS_2] 618
domains provide statistics. [IPv6Forum] analyzes 19 governmental
domains connected to either the European Union or its member states.
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+--------------+----------+---------+---------+---------+
|Country | Domains | DNS | Mail | Website |
| | analyzed | | | |
+--------------+----------+---------+---------+---------+
|China | 52 | 0.0% | 0.0% | 98.1% |
| | | | | |
+--------------+----------+---------+---------+---------+
|European | 19 | 47.4% | 0.0% | 21.1% |
|Union (*) | | | | |
+--------------+----------+---------+---------+---------+
|India | 618 | 7.6% | 6.5% | 7.1% |
| | | | | |
+--------------+----------+---------+---------+---------+
|United States | 1283 | 87.1% | 14.0% | 51.7% |
|of America | | | | |
+--------------+----------+---------+---------+---------+
Figure 8: IPv6 support for external-facing services across
governmental institutions
(*) Both EU and European governments domains are considered.
USA's IPv6 support is higher than other countries. This is likely
due to the IPv6 mandate set by [US-CIO]. In the case of India, the
degree of support seems still quite low. This is also true for
China, with the notable exception of high percentage of IPv6-enabled
websites for government-related organizations.
Similar statistics are also available for higher education. [NST_3]
measures the data from 346 second level domains of universities in
the US, such as example.edu. [BGR_3] looks at 111 Chinese education-
related domains. [CNLABS_3] analyzes 100 domains in India (mostly
third level), while [IPv6Forum] lists 118 universities in the
European Union (second level).
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+--------------+----------+---------+---------+---------+
|Country | Domains | DNS | Mail | Website |
| | analyzed | | | |
+--------------+----------+---------+---------+---------+
|China | 111 | 36.9% | 0.0% | 77.5% |
| | | | | |
+--------------+----------+---------+---------+---------+
|European | 118 | 83.9% | 43.2% | 35.6% |
|Union | | | | |
+--------------+----------+---------+---------+---------+
|India | 100 | 31.0% | 54.0% | 5.0% |
| | | | | |
+--------------+----------+---------+---------+---------+
|United States | 346 | 49.1% | 19.4% | 21.7% |
|of America | | | | |
+--------------+----------+---------+---------+---------+
Figure 9: IPv6 support for external-facing services across
universities
Overall, the universities have wider support of IPv6-based services
compared to the other sectors. Apart from a couple of exceptions
(e.g. the support of IPv6 mail in China and IPv6 web sites in India),
the numbers shown in the table above indicate a good support of IPv6
in academia.
3.4. Observations on Industrial Internet
There are potential advantages for using IPv6 for Industrial Internet
of Things (IIoT), in particular the large IPv6 address space, the
automatic IPv6 address configuration and resource discovery.
However, there are still many obstacles that prevent its pervasive
use. The key problems identified are the incomplete or immature tool
support, the dependency on manual configuration and the poor
knowledge of the IPv6 protocols. To promote the use of IPv6 for
smart manufacturing systems and IIoT applications a generic approach
to remove these pain points is highly desirable.
3.5. Observations on Content and Cloud Service Providers
The high number of addresses required to connect the virtual and
physical elements in a Data Center and the necessity to overcome the
limitation posed by [RFC1918] have been the drivers to the adoption
of IPv6 in several CSP networks.
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Several public references, as reported in Section 5.1.3, discuss how
most of the major players find themselves at different stages in the
transition to IPv6-only in their Data Center (DC) infrastructure. In
some cases, the transition already happened and the DC infrastructure
of these hyperscalers is completely based on IPv6.
3.6. Application Transition
The transition to IPv6 requires that the application software is
adapted for use in IPv6-based networks ([ARIN-SW] provides an
example). The use of transition mechanisms like 464XLAT is essential
to support IPv4-only applications while they evolve to IPv6.
Depending on the transition mechanism employed some issues may
remain. For example, in the case of NAT64/DNS64 the use of literal
IPv4 addresses, instead of DNS names, will fail, unless mechanisms
such as Application Level Gateways (ALG) are used. This issue is not
present in 464XLAT (see [RFC8683]).
It is worth mentioning Happy Eyeballs [RFC8305] as a relevant aspect
of application transition to IPv6.
4. IPv6 deployment scenarios
The scope of this section is to discuss the network and service
scenarios applicable for the transition to IPv6. Most of their
definitions have been provided in Section 1.1. This clause is
intended to focus on their technical and operational characteristics.
It is worth noticing that the sequence of scenarios described here
does not have necessarily to be intended as a roadmap for the IPv6
transition. Depending on their specific plans and requirements,
service providers may either adopt the scenarios proposed in a
sequence or jump directly to a specific one.
4.1. Dual-Stack
Based on answers provided by operators to the poll (Appendix A),
Dual-Stack [RFC4213] appears to be currently the most widely deployed
IPv6 solution (about 50%, see both Appendix A and the statistics
reported in [ETSI-IP6-WhitePaper]).
With Dual-Stack, IPv6 can be introduced together with other network
upgrades and many parts of network management and Information
Technology (IT) systems can still work in IPv4. This avoids major
upgrade of such systems to support IPv6, which is possibly the most
difficult task in the IPv6 transition. The cost and effort on the
network management and IT systems upgrade are moderate. The benefits
are to start using IPv6 and save NAT costs.
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Although Dual-Stack may provide advantages in the introductory stage,
it does have a few disadvantages in the long run, like the
duplication of the network resources and states. It also requires
more IPv4 addresses, thus increasing both Capital Expenses (CAPEX)
and Operating Expenses (OPEX). For example, even if private
addresses are used with Carrier-Grade NAT (CGN), there is extra
investment in the CGN devices, logs storage and helpdesk to track
CGN-related issues.
For this reason, when IPv6 usage exceeds certain threshold, it may be
advantageous to switch to start a transition to a next scenario. For
example, the process may start with the IPv6-only overlay stage and
IPv4aaS, as described hereinafter. It is difficult to establish the
criterion for switching (e.g. to properly identify the upper bound of
the IPv4 decrease or the lower bound of the IPv6 increase). In
addition to the technical factors, the switch to the next scenarios
may also cause a loss of customers. Based on feedbacks of network
operators participating in World IPv6 Launch [WIPv6L] in June 2021,
108 out of 346 operators exceed 50% of IPv6 traffic volume (31.2%),
72 exceed 60% (20.8%), while 37 exceed 75% (10.7%). The consensus to
move to IPv6-only might be reasonable when IPv6 traffic volume is
between 50% and 60%.
4.2. IPv4 as a Service and IPv6-only Overlay
As defined in Section 1.1, IPv6-only is generally associated with a
scope, e.g. IPv6-only overlay or IPv6-only underlay.
The IPv6-only overlay denotes that the overlay tunnel between the end
points of a network is based only on IPv6. It can be used to ensure
IPv4 support via IPv4aaS and it can be a complex decision that
depends on several factors, such as economic aspects, policy and
government regulation.
[I-D.ietf-v6ops-transition-comparison] compares the merits of the
most common transition solutions for IPv6-only service delivery, i.e.
464XLAT [RFC6877], DS-lite [RFC6333], Lightweight 4over6 (lw4o6)
[RFC7596], MAP-E [RFC7597], and MAP-T [RFC7599], but does not provide
an explicit recommendation. However, the poll in Appendix A
indicates that the most widely deployed IPv6 transition solution in
the MBB domain is 464XLAT while in the FBB domain is DS-Lite.
Both are IPv4aaS solutions by leveraging IPv6-only overlay. IPv4aaS
offers Dual-Stack service to users and allows an ISP to run IPv6-only
in the network (typically, the access network).
While it may not always be the case, IPv6-only transition
technologies such as 464XLAT require far fewer IPv4 addresses
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[I-D.ietf-v6ops-transition-comparison], because they make a more
efficient usage without restricting the number of ports per
subscriber. This helps to reduce troubleshooting costs and to remove
some operational issues related to permanent black-listing of IPv4
address blocks when used via CGN in some services.
IPv6-only overlay may be facilitated by the natural upgrade or
replacement of CEs because of newer technologies (tripe-play, higher
bandwidth WAN links, better WiFi technologies, etc.). The CAPEX and
OPEX of other parts of the network may be lowered (for example CGN
and associated logs) due to the operational simplification of the
network.
For applications with a large number of users (e.g. large mobile
operators) or a large number of hosts (e.g. large DCs), even the full
private address space [RFC1918] is not enough. Also, Dual-Stack will
likely lead to duplication of network resources and operations to
support both IPv6 and IPv4, which increases the amount of state
information in the network. This suggests that for scenarios such as
MBB or large DCs, IPv6-only overlay could be more efficient from the
start of the IPv6 introduction.
So, in general, when the Dual-Stack disadvantages outweigh the
IPv6-only complexity, it makes sense to transit to IPv6-only overlay.
Some network operators already started this process, as in the case
of [TMus], [RelJio] and [EE].
4.3. IPv6-only Underlay
As opposed to IPv6-only overlay and IPv4aaS, discussed in the
previous sections, IPv6-only underlay network uses IPv6 as the
network protocol for all traffic delivery. Both the control and data
planes are IPv6-based. The definition of IPv6-only underlay needs to
be associated with a scope in order to identify the domain where it
is applicable, such as IPv6-only access network or IPv6-only backbone
network.
As a matter of fact, IPv4 reachability must be provided for a long
time to come over IPv6 for IPv6-only hosts. Most ISPs are leveraging
CGN to extend the life of IPv4 instead of going with IPv4aaS.
When both enterprises and service providers start to transit from an
IPv4/MPLS backbone to introduce IPv6 in the underlay, they do not
necessarily need to dual-stack the underlay. Forwarding plane
complexity on the Provider (P) nodes of the ISP core should be kept
simple as a single protocol only backbone. An example could be
Softwire Mesh Framework [RFC5565]. This is based on IPv6 as the only
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protocol for the core network where IPv4 packets can be tunneled with
4to6 MPLS softwire encapsulation over the IPv6-only backbone.
Hence, when operators decide to transit to an IPv6 underlay, the ISP
backbone should be IPv6-only while Dual-Stack is not the best choice.
The underlay could be IPv6-only and allows IPv4 packets to be
tunneled using VPN over an IPv6-only backbone and leveraging
Advertising IPv4 Network Layer Routing Information (NLRI) with an
IPv6 Next Hop [RFC8950]. Indeed, [RFC8950] specifies the extensions
necessary to allow advertising IPv4 NLRI, Virtual Private Network
Unicast (VPN-IPv4) NLRI, Multicast Virtual Private Network (MVPN-
IPv4) NLRI with a Next Hop address that belongs to the IPv6 protocol.
And also, [I-D.ietf-bess-ipv6-only-pe-design] allows dual-stacked
functionality without having to dual-stack the interface and without
any tunneling mechanisms, resulting in OPEX savings for the
elimination of IPv4 addressing and BGP peering. This also enables
the quick deployment of IPv6 in a core or Data Center network without
provisioning IPv6 links with global unicast address, that can be a
long process in very large networks.
Therefore, IPv6-only underlay network deployment for access and
backbone network, seems not the first option and the current trend is
to keep IPv4/MPLS Data Plane and run IPv4/IPv6 Dual-Stack to edge
nodes.
As ISPs do the transition in the future to IPv6-only access and
backbone network, e.g. Segment Routing over IPv6 data plane (SRv6),
they are able to start the elimination of IPv4 from the underlay
transport network while continuing to provide IPv4 services.
Basically, as also showed by the poll among network operators, from a
network architecture perspective, it is not recommended to apply
Dual-Stack to the transport network per reasons mentioned above
related to the forwarding plane complexities.
4.4. IPv6-only
IPv6-only is the final stage of the IPv6 transition and it happens
when a complete network, end-to-end, no longer has IPv4. No IPv4
address is configured for network management or anything.
Since IPv6-only means that both underlay network and overlay services
are only IPv6, it will take longer to happen.
5. Common IPv6 Challenges
This section lists common IPv6 challenges in order to encourage more
investigations. Despite IPv6 has already been well-proven in
production, there are some challenges to consider. In this regard,
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it is worth noting that [ETSI-GR-IPE-001] also discusses gaps that
still exist in IPv6 related use cases.
5.1. Transition Choices
A service provider or an enterprise may perceive quite a complex task
the transition to IPv6, due to the many technical alternatives
available and the changes required in management and operations.
Moreover, the choice of the method to support the transition may
depend on factors specific to the operator's or the enterprise's
context, such as the IPv6 network design that fits the service
requirements, the network operations and the deployment strategy.
This section briefly highlights the approaches that service providers
and enterprises may take and the related challenges.
5.1.1. Service Providers
For fixed operators, the massive software upgrade of CEs to support
Dual-Stack already started in most of service provider networks. On
average, looking at the global statistics, the IPv6 traffic
percentage is currently around 40%. As highlighted earlier, all
major content providers have already implemented Dual-Stack access to
their services and most of them have implemented IPv6-only in their
Data Centers. This aspect could affect the decision on the IPv6
adoption for an operator, but there are also other factors like the
current IPv4 address shortage, CE costs, CGN costs and so on.
Fixed Operators with a Dual-Stack architecture, can start defining
and apply a new strategy when reaching the limit in terms of
number of IPv4 addresses available. This may be done through CGN
or with an IPv4aaS approach.
Most of the fixed operators remain attached to a Dual-Stack
architecture and have already employed CGN. In this case it is
likely that CGN boosts their ability to supply IPv4 connectivity
to CEs for more years to come. Indeed, only few fixed operators
have chosen to move to an IPv6-only scenario.
For mobile operators, the situation is quite different since, in some
cases, mobile operators are already stretching their IPv4 address
space. The reason is that CGN translation limits have been reached
and no more IPv4 public pool addresses are available.
Some mobile operators choose to implement Dual-Stack as first and
immediate mitigation solution.
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Other mobile operators prefer to move to IPv4aaS solutions (e.g.
464XLAT) since Dual-Stack only mitigates and does not solve
completely the IPv4 address scarcity issue.
For both fixed and mobile operators the approach for the transition
is not unique and this bring different challenges in relation to the
network architecture and related costs. So each operator needs to do
own evaluations for the transition based on the specific situation.
5.1.2. Enterprises and Industrial Internet
At present, the challenge for enterprises mainly relies on upstream
service providers. Often, the enterprise connectivity depends on the
services provided by their upstream provider. As pointed out in
Section 3, enterprises may benefit deploying IPv6 in their public-
facing services. IPv6 also shows its advantages in the case of
merger and acquisition, to avoid overlapping of the two address
spaces. In addition, since several governments are introducing IPv6
policy, all the enterprises providing consulting service to
governments are also required to support IPv6.
Enterprises are shielded from IPv4 address depletion issues due to
their predominantly use of Proxy and private addressing [RFC1918],
thus do not have the business requirement or technical justification
to transit to IPv6. Enterprises need to find a business case and a
strong motivation for IPv6 transition to justify additional CAPEX and
OPEX. Also, since Information and Communication Technologies (ICT)
is not the core business for most of the enterprises, ICT budget is
often constrained and cannot expand considerably. However, there are
examples of big enterprises that are considering IPv6 to achieve
business targets through a more efficient IPv6 network and to
introduce newer services which require IPv6 network architecture.
Enterprises worldwide, in particular small and medium-sized, are
quite late to adopt IPv6, especially on internal networks. In most
cases, the enterprise engineers and technicians do not know well how
IPv6 works and the problem of application porting to IPv6 looks quite
difficult, even if technically is not a big issue. As highlighted in
the relevant poll, the technicians may want to get trained but the
management do not see a business need for adoption. This creates an
unfortunate cycle where misinformation about the complexity of the
IPv6 protocol and unreasonable fears about security and manageability
combine with the perceived lack of urgent business needs to prevent
adoption of IPv6. In 2019 and 2020, there has been a concerted
effort by some ARIN and APNIC initiatives to provide training
[ARIN-CG] [ISIF-ASIA-G].
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As the most promising protocol for network evolution, IPv6 is
frequently mentioned in relation to Internet of Things and Industry
4.0. However, its industrial adoption, in particular in smart
manufacturing systems, has been much slower than expected. Indeed,
as for enterprises, it is important to provide an easy way to
familiarize system architects and software developers with the IPv6
protocol.
For Industrial Internet and related IIoT applications, it would be
desirable to be able to implement a truly distributed system without
dependencies to central components. In this regard the distributed
IIoT applications can leverage the configuration-less characteristic
of IPv6. In addition, it could be interesting to have the ability to
use IP based communication and standard application protocols at
every point in the production process and further reduce the use of
specialized communication systems.
5.1.3. Cloud and Data Centers
Most CSPs have adopted IPv6 in their internal infrastructure but are
also active in gathering IPv4 addresses on the transfer market to
serve the current business needs of IPv4 connectivity. As noted in
the previous section, most enterprises do not consider the transition
to IPv6 as a priority. To this extent, the use of IPv4-based network
services by the CSPs will last. Indeed, CSPs are struggling to buy
IPv4 addresses.
It is interesting to look at how much traffic in a network is going
to Caches and Content Delivery Networks (CDNs). The response is
expected to be an high percentage, at least higher than 50% in most
of the cases. Since all the key Caches and CDNs are IPv6-ready
[Cldflr], [Akm], [Ggl], [Ntflx], [Amzn], [Mcrsft], [Vrzn]. So the
percentage of traffic going to the key Caches/CDNs is a good
approximation of the potential IPv6 traffic in a network.
The challenge for CSPs is related to the support of non-native IPv4
since most CSPs provide native IPv6. If, in the next years, the
scarcity of IPv4 addresses becomes more evident, it is likely that
the cost of buying an IPv4 address by a CSP could be charged to their
customers.
5.1.4. CEs and user devices
It can be noted that most of the user devices (e.g. smartphones) are
already IPv6-enabled since so many years. But there are exceptions,
for example, smartTVs and Set-Top Box (STBs) typically had IPv6
support since few years ago, however not all the economies replace
them at the same pace.
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As already mentioned, ISPs who historically provided public IPv4
addresses to their customers generally still have those IPv4
addresses (unless they chose to transfer them). Some have chosen to
put new customers on CGN but without touching existing customers.
Because of the extremely small number of customers who notice that
IPv4 is done via NAT444, it could be less likely to run out of IPv4
addresses and private IPv4 space. But as IPv4-only devices and
traffic reduce, then the need to support private and public IPv4
become less. So the complete support of CEs to IPv6 is also an
important challenge and incentive to overcome Dual-Stack towards
IPv4aaS solution [ANSI].
5.2. Network Management and Operations
There are important IPv6 complementary solutions related to
Operations, Administration and Maintenance (OAM) that look not so
complete compared to IPv4. Network Management System (NMS) has a
central role in the modern networks for both network operators and
enterprises and its transition is a fundamental challenge. This is
because some IPv6 products are not field-proven as for IPv4 even if
traditional protocols (e.g. SNMP, RADIUS) already support IPv6. In
addition, incompatible vendor roadmap for the development of new NMS
features affects the confidence of network operators or enterprises.
For example, YANG is the configuration language for networking but in
the real world the data modeling is still vendor dependent.
An important factor is represented by the need for training the
network operations workforce. Deploying IPv6 requires it as policies
and procedures have to be adjusted in order to successfully plan and
complete an IPv6 transition. Staff has to be aware of the best
practices for managing IPv4 and IPv6 assets. In addition to network
nodes, network management applications and equipment need to be
properly configured and in some cases also replaced. This may
introduce more complexity and costs for the transition.
Availability of both systems and training is necessary in areas such
as IPv6 addressing. IPv6 addresses can be assigned to an interface
through different means, such as Stateless Auto-Configuration (SLAAC)
[RFC4862], stateful and stateless Dynamic Host Control Protocol
(DHCP) [RFC8415]. IP Address Management (IPAM) systems may
contribute to handle the technical differences and automate some of
the configuration tasks, such as the address assignment or the
management of DHCP services.
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5.3. Performance
People tend to compare the performance of IPv6 versus IPv4 to argue
or motivate the IPv6 transition. In some cases, IPv6 behaving
"worse" than IPv4 may be used as an argument for avoiding the full
adoption of IPv6. However, there are some aspects where IPv6 is
filling the gap to IPv4. This position is supported when looking at
available analytics on two critical parameters: packet loss and
latency. These parameters have been constantly monitored over time,
but only a few extensive researches and measurement campaigns are
currently providing up-to-date information. While performance is
undoubtedly an important issue to consider and worth further
investigation, reality is that a definitive answer cannot be found on
what IP version performs better. Depending on the specific use case
and application, IPv6 is better; in others the same applies to IPv4.
5.3.1. IPv6 packet loss and latency
[APNIC5] provides a measurement of both the failure rate and RTT of
IPv6 compared against IPv4. Both measures are based on scripts that
employs the three-way handshake of TCP. As such, the measurement of
the failure rate does not provide a direct measurement of packet loss
(that would need an Internet-wide measurement campaign). Said that,
despite IPv4 is still performing better, the difference seems to have
decreased in recent years. Two reports, namely [RIPE1] and
[APRICOT], discussed the associated trend, showing how the average
worldwide failure rate of IPv6 is still a bit worse than IPv4.
Reasons for this effect may be found in endpoints with an unreachable
IPv6 address, routing instability or firewall behavior. Yet, this
worsening effect may appear as disturbing for a plain transition to
IPv6.
[APNIC5] also compares the latency of both address families.
Currently, the worldwide average is still in favor of IPv4. Zooming
at the country or even at the operator level, it is possible to get
more detailed information and appreciate that cases exist where IPv6
is faster than IPv4. Regions (e.g. Western Europe, Northern
America, Southern Asia) and Countries (e.g. US, India, Germany) with
an advanced deployment of IPv6 (e.g. >45%) are showing that IPv6 has
better performance than IPv4. [APRICOT] highlights how when a
difference in performance exists it is often related to asymmetric
routing issues. Other possible explanations for a relative latency
difference lays on the specificity of the IPv6 header which allows
packet fragmentation. In turn, this means that hardware needs to
spend cycles to analyze all of the header sections and when it is not
capable of handling one of them it drops the packet. Even
considering this, a difference in latency stands and sometimes it is
perceived as a limiting factor for IPv6. A few measurement campaigns
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on the behavior of IPv6 in CDNs are also available [MAPRG],
[INFOCOM]. The TCP connect time is still higher for IPv6 in both
cases, even if the gap has reduced over the analysis time window.
5.3.2. Customer Experience
It is not totally clear if the Customer Experience is in some way
perceived as better when IPv6 is used instead of IPv4. In some cases
it has been publicly reported by IPv6 content providers, that users
have a better experience when using IPv6-only compared to IPv4
[ISOC2]. This could be explained because in the case of an IPv6 user
connecting to an application hosted in an IPv6-only Data Centers, the
connection is end-to-end, without translations. Instead, when using
IPv4 there is a NAT translation either in the CE or in the service
provider's network, in addition to IPv4 to IPv6 (and back to IPv4)
translation in the IPv6-only content provider Data Center. [ISOC2],
[FB] provide reasons in favor of IPv6. In other cases, the result
seems to be still slightly in favor of IPv4 [INFOCOM], [MAPRG], even
if the difference between IPv4 and IPv6 tends to vanish over time.
5.4. IPv6 security and privacy
An important point that is sometimes considered as a challenge when
discussing the transition to IPv6 is related to the security and
privacy. [RFC9099] analyzes the operational security issues in
several places of a network (enterprises, service providers and
residential users). It is also worth considering the additional
security issues brought by the applied IPv6 transition technologies
used to implement IPv4aaS, e.g. 464XLAT, DS-Lite. Some hints are in
the paper [ComputSecur].
The security aspects have to be considered to keep at least the same
or even a better level of security as it exists nowadays in an IPv4
network environment. The autoconfiguration features of IPv6 will
require some more attention. Router discovery and address
autoconfiguration may produce unexpected results and security holes.
IPsec protects IPv6 traffic at least as well as it does IPv4, and the
security protocols for constrained devices (IoT) are designed for
IPv6 operation.
IPv6 was designed to restore the end-to-end model of communications
with all nodes on networks using globally unique addresses. But,
considering this, IPv6 may imply privacy concerns, due to greater
visibility on the Internet. IPv6 nodes can (and typically do) use
privacy extensions [RFC8981] to prevent any tracking of their burned-
in MAC address(es), which are easily readable in the original
modified EUI-64 interface identifier format. But, on the other hand,
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stable IPv6 interface identifiers ([RFC8064]) were developed and this
can also affect privacy.
As reported in [ISOC3], comparing IPv6 and IPv4 at the protocol
level, one may probably conclude that the increased complexity of
IPv6 results in an increased number of attack vectors, that imply
more possible ways to perform different types of attacks. However, a
more interesting and practical question is how IPv6 deployments
compare to IPv4 deployments in terms of security. In that sense,
there are a number of aspects to consider.
Most security vulnerabilities related to network protocols are based
on implementation flaws. Typically, security researchers find
vulnerabilities in protocol implementations, which eventually are
"patched" to mitigate such vulnerabilities. Over time, this process
of finding and patching vulnerabilities results in more robust
implementations. For obvious reasons, the IPv4 protocols have
benefited from the work of security researchers for much longer, and
thus, IPv4 implementations are generally more robust than IPv6.
However, with more IPv6 deployment, IPv6 will also benefit from this
process in the long run.
Besides the intrinsic properties of the protocols, the security level
of the resulting deployments is closely related to the level of
expertise of network and security engineers. In that sense, there is
obviously much more experience and confidence with deploying and
operating IPv4 networks than with deploying and operating IPv6
networks.
5.4.1. Protocols security issues
It is important to say that IPv6 is not more or less secure than IPv4
and the knowledge of the protocol is the best security measure.
In general there are security concerns related to IPv6 that can be
classified as follows:
o Basic IPv6 protocol (Basic header, Extension Headers, Addressing)
o IPv6 associated protocols (ICMPv6, NDP, MLD, DNS, DHCPv6)
o Internet-wide IPv6 security (Filtering, DDoS, Transition
Mechanisms)
ICMPv6 is an integral part of IPv6 and performs error reporting and
diagnostic functions. Neighbor Discovery Protocol (NDP) is a node
discovery protocol in IPv6 which replaces and enhances functions of
ARP. Multicast Listener Discovery (MLD) is used by IPv6 routers for
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discovering multicast listeners on a directly attached link, much
like Internet Group Management Protocol (IGMP) is used in IPv4.
These IPv6 associated protocols like ICMPv6, NDP and MLD are
something new compared to IPv4, so they add new security threats and
the related solutions are still under discussion today. NDP has
vulnerabilities [RFC3756] [RFC6583]. The specification says to use
IPsec but it is impractical and not used, on the other hand, SEND
(SEcure Neighbour Discovery) [RFC3971] is not widely available.
[RIPE2] describes the most important threats and solutions regarding
IPv6 security.
5.4.2. IPv6 Extension Headers and Fragmentation
IPv6 Extension Headers provide a hook for interesting new features to
be added, and are more flexible than IPv4 Options. This does add
some complexity, and in particular some security mechanisms may
require to process the full chain of headers, and some firewalls may
require to filter packets based on their Extension Headers.
Additionally, packets with IPv6 Extension Headers may be dropped in
the public Internet [RFC7872]. Some documents, e.g.
[I-D.ietf-6man-hbh-processing], [I-D.ietf-v6ops-hbh],
[I-D.bonica-6man-ext-hdr-update], analyze and provide guidance
regarding the processing procedures of IPv6 Extension Headers.
Defence against possible attacks through Extension Headers is
necessary. For example, the original IPv6 Routing Header type 0
(RH0) was deprecated because of possible remote traffic
amplification. In addition, it is worth mentioning that unrecognized
Hop-by-Hop Options Header and Destination Options Header will not be
considered by the nodes if they are not configured to deal with it
[RFC8200]. Other attacks based on Extension Headers may be based on
IPv6 Header Chains and Fragmentation that could be used to bypass
filtering, but to mitigate this effect, Header chain should go only
in the first fragment and the use of the IPv6 Fragmentation Header is
forbidden in all Neighbor Discovery messages [RFC6980].
Fragment Header is used by IPv6 source node to send a packet bigger
than path MTU and the Destination host processes fragment headers.
There are several threats related to fragmentation to pay attention
to e.g. overlapping fragments (not allowed) resource consumption
while waiting for last fragment (to discard), atomic fragments (to be
isolated).
The operational implications of IPv6 Packets with Extension Headers
are further discussed in [RFC9098].
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6. Security Considerations
This document has no impact on the security properties of specific
IPv6 protocols or transition tools. In addition to the discussion
above in Section 5.4, the security considerations relating to the
protocols and transition tools are described in the relevant
documents.
7. Contributors
Sebastien Lourdez
Post Luxembourg
Email: sebastien.lourdez@post.lu
8. Acknowledgements
The authors of this document would like to thank Brian Carpenter,
Fred Baker, Alexandre Petrescu, Fernando Gont, Barbara Stark,
Haisheng Yu(Johnson), Dhruv Dhody, Gabor Lencse, Shuping Peng, Daniel
Voyer, Daniel Bernier, Hariharan Ananthakrishnan, Donavan Fritz, Igor
Lubashev, Erik Nygren, Eduard Vasilenko and Xipeng Xiao for their
comments and review of this document.
9. IANA Considerations
This document has no actions for IANA.
10. References
10.1. Normative References
[I-D.ietf-v6ops-transition-comparison]
Lencse, G., Martinez, J. P., Howard, L., Patterson, R.,
and I. Farrer, "Pros and Cons of IPv6 Transition
Technologies for IPv4aaS", draft-ietf-v6ops-transition-
comparison-04 (work in progress), May 2022.
[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,
and E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996,
<https://www.rfc-editor.org/info/rfc1918>.
[RFC3756] Nikander, P., Ed., Kempf, J., and E. Nordmark, "IPv6
Neighbor Discovery (ND) Trust Models and Threats",
RFC 3756, DOI 10.17487/RFC3756, May 2004,
<https://www.rfc-editor.org/info/rfc3756>.
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[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<https://www.rfc-editor.org/info/rfc3971>.
[RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms
for IPv6 Hosts and Routers", RFC 4213,
DOI 10.17487/RFC4213, October 2005,
<https://www.rfc-editor.org/info/rfc4213>.
[RFC6036] Carpenter, B. and S. Jiang, "Emerging Service Provider
Scenarios for IPv6 Deployment", RFC 6036,
DOI 10.17487/RFC6036, October 2010,
<https://www.rfc-editor.org/info/rfc6036>.
[RFC6180] Arkko, J. and F. Baker, "Guidelines for Using IPv6
Transition Mechanisms during IPv6 Deployment", RFC 6180,
DOI 10.17487/RFC6180, May 2011,
<https://www.rfc-editor.org/info/rfc6180>.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011,
<https://www.rfc-editor.org/info/rfc6333>.
[RFC6540] George, W., Donley, C., Liljenstolpe, C., and L. Howard,
"IPv6 Support Required for All IP-Capable Nodes", BCP 177,
RFC 6540, DOI 10.17487/RFC6540, April 2012,
<https://www.rfc-editor.org/info/rfc6540>.
[RFC6583] Gashinsky, I., Jaeggli, J., and W. Kumari, "Operational
Neighbor Discovery Problems", RFC 6583,
DOI 10.17487/RFC6583, March 2012,
<https://www.rfc-editor.org/info/rfc6583>.
[RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT:
Combination of Stateful and Stateless Translation",
RFC 6877, DOI 10.17487/RFC6877, April 2013,
<https://www.rfc-editor.org/info/rfc6877>.
[RFC6883] Carpenter, B. and S. Jiang, "IPv6 Guidance for Internet
Content Providers and Application Service Providers",
RFC 6883, DOI 10.17487/RFC6883, March 2013,
<https://www.rfc-editor.org/info/rfc6883>.
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[RFC7381] Chittimaneni, K., Chown, T., Howard, L., Kuarsingh, V.,
Pouffary, Y., and E. Vyncke, "Enterprise IPv6 Deployment
Guidelines", RFC 7381, DOI 10.17487/RFC7381, October 2014,
<https://www.rfc-editor.org/info/rfc7381>.
[RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I.
Farrer, "Lightweight 4over6: An Extension to the Dual-
Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596,
July 2015, <https://www.rfc-editor.org/info/rfc7596>.
[RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, Ed., "Mapping of Address and
Port with Encapsulation (MAP-E)", RFC 7597,
DOI 10.17487/RFC7597, July 2015,
<https://www.rfc-editor.org/info/rfc7597>.
[RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S.,
and T. Murakami, "Mapping of Address and Port using
Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July
2015, <https://www.rfc-editor.org/info/rfc7599>.
[RFC8950] Litkowski, S., Agrawal, S., Ananthamurthy, K., and K.
Patel, "Advertising IPv4 Network Layer Reachability
Information (NLRI) with an IPv6 Next Hop", RFC 8950,
DOI 10.17487/RFC8950, November 2020,
<https://www.rfc-editor.org/info/rfc8950>.
[RFC9099] Vyncke, E., Chittimaneni, K., Kaeo, M., and E. Rey,
"Operational Security Considerations for IPv6 Networks",
RFC 9099, DOI 10.17487/RFC9099, August 2021,
<https://www.rfc-editor.org/info/rfc9099>.
10.2. Informative References
[Akm] Akamai, "IPv6 Adaptation",
<https://www.akamai.com/us/en/multimedia/documents/
product-brief/ipv6-adaptation-product-brief.pdf>.
[Akm-stats]
Akamai, "IPv6 Adoption Visualization", 2021,
<https://www.akamai.com/uk/en/resources/our-thinking/
state-of-the-internet-report/state-of-the-internet-ipv6-
adoption-visualization.jsp>.
[Alx] Alexa, "The top 500 sites on the web", 2021,
<https://www.alexa.com/topsites>.
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[Amzn] Amazon, "Announcing Internet Protocol Version 6 (IPv6)
support for Amazon CloudFront, AWS WAF, and Amazon S3
Transfer Acceleration", <https://aws.amazon.com/es/about-
aws/whats-new/2016/10/ipv6-support-for-cloudfront-waf-and-
s3-transfer-acceleration/>.
[ANSI] ANSI/CTA, "ANSI/CTA Standard Host and Router Profiles for
IPv6", 2020, <https://shop.cta.tech/products/host-and-
router-profiles-for-ipv6>.
[APNIC1] APNIC, "IPv6 Capable Rate by country (%)", 2022,
<https://stats.labs.apnic.net/ipv6>.
[APNIC2] APNIC2, "IP Addressing 2021", 2022,
<https://blog.apnic.net/2022/01/19/ip-addressing-in-
2021/>.
[APNIC3] APNIC, "BGP in 2020 - The BGP Table", 2021,
<https://blog.apnic.net/2021/01/05/bgp-in-2020-the-bgp-
table/>>.
[APNIC4] APNIC, "BGP in 2021 - The BGP Table", 2022,
<https://blog.apnic.net/2022/01/06/bgp-in-2021-the-bgp-
table/>>.
[APNIC5] APNIC, "Average RTT Difference (ms) (V6 - V4) for World
(XA)", 2022, <https://stats.labs.apnic.net/v6perf/XA>.
[APRICOT] Huston, G., "Average RTT Difference (ms) (V6 - V4) for
World (XA)", 2020,
<https://2020.apricot.net/assets/files/APAE432/ipv6-
performance-measurement.pdf>.
[ARCEP] ARCEP, "Arcep Decision no 2019-1386, Decision on the terms
and conditions for awarding licences to use frequencies in
the 3.4-3.8GHz band", 2019,
<https://www.arcep.fr/uploads/tx_gsavis/19-1386.pdf>.
[ARIN-CG] ARIN, "Community Grant Program: IPv6 Security,
Applications, and Training for Enterprises", 2020,
<https://www.arin.net/about/community_grants/recipients/>.
[ARIN-SW] ARIN, "Preparing Applications for IPv6",
<https://www.arin.net/resources/guide/ipv6/
preparing_apps_for_v6.pdf>.
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[BGR_1] BIIGROUP, "China Commercial IPv6 and DNSSEC Deployment
Monitor", 2022,
<http://218.2.231.237:5001/cgi-bin/generate>.
[BGR_2] BIIGROUP, "China Government IPv6 and DNSSEC Deployment
Monitor", 2022,
<http://218.2.231.237:5001/cgi-bin/generate_gov>.
[BGR_3] BIIGROUP, "China Education IPv6 and DNSSEC Deployment
Monitor", 2022,
<http://218.2.231.237:5001/cgi-bin/generate_edu>.
[BIPT] Belgian Institute for Postal services and
Telecommunications, "IPv6 in Belgium", 2017,
<https://www.ripe.net/participate/meetings/roundtable/
september-2017/government-roundtable-meeting-bahrain-26-
september-2017/presentations/belgium-experience-bahrain-
roundtable.pdf>.
[CAIDA] APNIC, "Client-Side IPv6 Measurement", 2020,
<https://www.cmand.org/workshops/202006-v6/
slides/2020-06-16-client-side.pdf>.
[CAIR] Cisco, "Cisco Annual Internet Report (2018-2023) White
Paper", 2020,
<https://www.cisco.com/c/en/us/solutions/collateral/
executive-perspectives/annual-internet-report/white-paper-
c11-741490.html>.
[Cldflr] Cloudflare, "Understanding and configuring Cloudflare's
IPv6 support", <https://support.cloudflare.com/hc/en-us/
articles/229666767-Understanding-and-configuring-
Cloudflare-s-IPv6-support>.
[cmpwr] Compuware, "Impact on Enterprises of the IPv6-Only
direction for the US Federal Government", 2020,
<https://mydigitalpublication.com/article/
Impact+on+Enterprises+of+the+IPv6-Only+Direction+for+the+U
.S.+Federal+Government/3702828/664279/article.html>.
[CN] China.org.cn, "China to speed up IPv6-based Internet
development", 2017, <http://www.china.org.cn/
business/2017-11/27/content_41948814.htm>.
[CN-IPv6] National IPv6 Deployment and Monitoring Platform, "Active
IPv6 Internet users", 2022,
<https://www.china-ipv6.cn/#/activeconnect/simpleInfo>.
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[CNLABS_1]
CNLABS, "Industry IPv6 and DNSSEC Statistics", 2022,
<https://cnlabs.in/IPv6_Mon/generate_industry.html>.
[CNLABS_2]
CNLABS, "Industry IPv6 and DNSSEC Statistics", 2022,
<https://cnlabs.in/IPv6_Mon/generate_gov.html>.
[CNLABS_3]
CNLABS, "Industry IPv6 and DNSSEC Statistics", 2022,
<https://cnlabs.in/IPv6_Mon/generate_industry.html>.
[ComputSecur]
Computers & Security (Elsevier), "Methodology for the
identification of potential security issues of different
IPv6 transition technologies: Threat analysis of DNS64 and
stateful NAT64", DOI 10.1016/j.cose.2018.04.012, 2018.
[Csc6lab] Cisco, "World - Display Content Data", 2022,
<https://6lab.cisco.com/stats/>.
[EE] EE, "IPv6-only devices on EE mobile", 2017,
<https://indico.uknof.org.uk/event/38/contributions/489/
attachments/612/736/
Nick_Heatley_EE_IPv6_UKNOF_20170119.pdf>.
[ETSI-GR-IPE-001]
ETSI, "ETSI GR IPE 001: IPv6 Enhanced Innovation (IPE) Gap
Analysis", 2021, <https://www.etsi.org/deliver/etsi_gr/
IPE/001_099/001/01.01.01_60/gr_IPE001v010101p.pdf>.
[ETSI-IP6-WhitePaper]
ETSI, "ETSI White Paper No. 35: IPv6 Best Practices,
Benefits, Transition Challenges and the Way Forward",
ISBN 979-10-92620-31-1, 2020.
[FB] Saab, P., "Facebook IPv6 Experience", 2015,
<https://youtu.be/An7s25FSK0U>.
[G_stats] Google, "Google IPv6 Per-Country IPv6 adoption", 2021,
<https://www.google.com/intl/en/ipv6/
statistics.html#tab=per-country-ipv6-adoption>.
[GFA] German Federal Government Commissioner for Information
Technology, "IPv6-Masterplan fuer die Bundesverwaltung",
2019, <https://media.frag-den-staat.de/files/foi/531501/
de-government-ipv6-masterplan-
v100-entwurf_konvertiert.pdf>.
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[Ggl] Google, "Introduction to GGC",
<https://support.google.com/interconnect/
answer/9058809?hl=en>.
[HxBld] HexaBuild, "IPv6 Adoption Report 2020", 2020,
<https://hexabuild.io/assets/files/HexaBuild-IPv6-
Adoption-Report-2020.pdf>.
[I-D.bonica-6man-ext-hdr-update]
Bonica, R. and T. Jinmei, "Inserting, Processing And
Deleting IPv6 Extension Headers", draft-bonica-6man-ext-
hdr-update-07 (work in progress), February 2022.
[I-D.ietf-6man-hbh-processing]
Hinden, R. M. and G. Fairhurst, "IPv6 Hop-by-Hop Options
Processing Procedures", draft-ietf-6man-hbh-processing-01
(work in progress), July 2022.
[I-D.ietf-bess-ipv6-only-pe-design]
Mishra, G., Mishra, M., Tantsura, J., Madhavi, S., Yang,
Q., Simpson, A., and S. Chen, "IPv6-Only PE Design for
IPv4-NLRI with IPv6-NH", draft-ietf-bess-ipv6-only-pe-
design-02 (work in progress), March 2022.
[I-D.ietf-v6ops-hbh]
Peng, S., Li, Z., Xie, C., Qin, Z., and G. Mishra,
"Operational Issues with Processing of the Hop-by-Hop
Options Header", draft-ietf-v6ops-hbh-01 (work in
progress), April 2022.
[I-D.palet-v6ops-ipv6-only]
Martinez, J. P., "IPv6-only Terminology Definition",
draft-palet-v6ops-ipv6-only-05 (work in progress), March
2020.
[IAB] IAB, "IAB Statement on IPv6", 2016,
<https://www.iab.org/2016/11/07/iab-statement-on-ipv6/>.
[IDT] Indian Department of Telecommunications, "Revision of IPv6
Transition Timelines", 2021, <https://dot.gov.in/revision-
ipv6-transition-timelines-2021>.
[IGP-GT] Internet Governance Project, Georgia Tech, "The hidden
standards war: economic factors affecting IPv6
deployment", 2019, <https://via.hypothes.is/
https://www.internetgovernance.org/wp-content/uploads/
IPv6-Migration-Study-final-report.pdf>.
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[INFOCOM] Doan, T., "A Longitudinal View of Netflix: Content
Delivery over IPv6 and Content Cache Deployments", 2020,
<https://dl.acm.org/doi/abs/10.1109/
INFOCOM41043.2020.9155367>.
[IPv6Forum]
IPv6Forum, "Estimating IPv6 & DNSSEC External Service
Deployment Status", 2022,
<https://www.ipv6forum.com/IPv6-Monitoring/index.html>.
[ISIF-ASIA-G]
ISIF Asia, "Internet Operations Research Grant: IPv6
Deployment at Enterprises. IIESoc. India", 2020,
<https://isif.asia/2020-grantees/>.
[ISOC1] Internet Society, "State of IPv6 Deployment 2018", 2018,
<https://www.internetsociety.org/resources/2018/state-of-
ipv6-deployment-2018/>.
[ISOC2] Internet Society, "Facebook News Feeds Load 20-40% Faster
Over IPv6", 2015,
<https://www.internetsociety.org/blog/2015/04/facebook-
news-feeds-load-20-40-faster-over-ipv6/>.
[ISOC3] Internet Society, "IPv6 Security FAQ", 2019,
<https://www.internetsociety.org/wp-
content/uploads/2019/02/Deploy360-IPv6-Security-FAQ.pdf>.
[MAPRG] Bajpai, V., "Measuring YouTube Content Delivery over
IPv6", 2017, <https://www.ietf.org/proceedings/99/slides/
slides-99-maprg-measuring-youtube-content-delivery-over-
ipv6-00.pdf>.
[Mcrsft] Microsoft, "IPv6 for Azure VMs available in most regions",
<https://azure.microsoft.com/en-us/updates/ipv6-for-azure-
vms/>.
[NRO] NRO, "Internet Number Resource Status Report", 2021,
<https://www.nro.net/wp-content/uploads/NRO-Statistics-
2021-Q3-FINAL.pdf>.
[NST_1] NIST, "Estimating Industry IPv6 and DNSSEC External
Service Deployment Status", 2022, <https://fedv6-
deployment.antd.nist.gov/cgi-bin/generate-com>.
[NST_2] NIST, "Estimating USG IPv6 and DNSSEC External Service
Deployment Status", 2022, <https://fedv6-
deployment.antd.nist.gov/cgi-bin/generate-gov>.
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[NST_3] NIST, "Estimating University IPv6 and DNSSEC External
Service Deployment Status", 2022, <https://fedv6-
deployment.antd.nist.gov/cgi-bin/generate-edu>.
[Ntflx] Netflix, "Enabling Support for IPv6",
<https://netflixtechblog.com/enabling-support-for-
ipv6-48a495d5196f>.
[POTAROO1]
POTAROO, "IP Addressing through 2021", 2022,
<https://www.potaroo.net/ispcol/2022-01/addr2021.html>.
[POTAROO2]
POTAROO, "IPv6 Resource Allocations", 2022,
<https://www.potaroo.net/bgp/iso3166/v6cc.html>.
[RelJio] Reliance Jio, "IPv6-only adoption challenges and
standardization requirements", 2020,
<https://datatracker.ietf.org/meeting/109/materials/
slides-109-v6ops-ipv6-only-adoption-challenges-and-
standardization-requirements-03>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>.
[RFC5565] Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh
Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009,
<https://www.rfc-editor.org/info/rfc5565>.
[RFC6264] Jiang, S., Guo, D., and B. Carpenter, "An Incremental
Carrier-Grade NAT (CGN) for IPv6 Transition", RFC 6264,
DOI 10.17487/RFC6264, June 2011,
<https://www.rfc-editor.org/info/rfc6264>.
[RFC6980] Gont, F., "Security Implications of IPv6 Fragmentation
with IPv6 Neighbor Discovery", RFC 6980,
DOI 10.17487/RFC6980, August 2013,
<https://www.rfc-editor.org/info/rfc6980>.
[RFC7872] Gont, F., Linkova, J., Chown, T., and W. Liu,
"Observations on the Dropping of Packets with IPv6
Extension Headers in the Real World", RFC 7872,
DOI 10.17487/RFC7872, June 2016,
<https://www.rfc-editor.org/info/rfc7872>.
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[RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu,
"Recommendation on Stable IPv6 Interface Identifiers",
RFC 8064, DOI 10.17487/RFC8064, February 2017,
<https://www.rfc-editor.org/info/rfc8064>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[RFC8305] Schinazi, D. and T. Pauly, "Happy Eyeballs Version 2:
Better Connectivity Using Concurrency", RFC 8305,
DOI 10.17487/RFC8305, December 2017,
<https://www.rfc-editor.org/info/rfc8305>.
[RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A.,
Richardson, M., Jiang, S., Lemon, T., and T. Winters,
"Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 8415, DOI 10.17487/RFC8415, November 2018,
<https://www.rfc-editor.org/info/rfc8415>.
[RFC8683] Palet Martinez, J., "Additional Deployment Guidelines for
NAT64/464XLAT in Operator and Enterprise Networks",
RFC 8683, DOI 10.17487/RFC8683, November 2019,
<https://www.rfc-editor.org/info/rfc8683>.
[RFC8981] Gont, F., Krishnan, S., Narten, T., and R. Draves,
"Temporary Address Extensions for Stateless Address
Autoconfiguration in IPv6", RFC 8981,
DOI 10.17487/RFC8981, February 2021,
<https://www.rfc-editor.org/info/rfc8981>.
[RFC9098] Gont, F., Hilliard, N., Doering, G., Kumari, W., Huston,
G., and W. Liu, "Operational Implications of IPv6 Packets
with Extension Headers", RFC 9098, DOI 10.17487/RFC9098,
September 2021, <https://www.rfc-editor.org/info/rfc9098>.
[RIPE1] Huston, G., "Measuring IPv6 Performance", 2016,
<https://ripe73.ripe.net/wp-content/uploads/
presentations/35-2016-10-24-v6-performance.pdf>.
[RIPE2] RIPE, "IPv6 Security", 2019,
<https://www.ripe.net/support/training/material/ipv6-
security/ipv6security-slides.pdf>.
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[SNDVN] SANDVINE, "Sandvine releases 2020 Mobile Internet
Phenomena Report: YouTube is over 25% of all mobile
traffic", 2020, <https://www.sandvine.com/press-releases/
sandvine-releases-2020-mobile-internet-phenomena-report-
youtube-is-over-25-of-all-mobile-traffic>.
[TMus] T-Mobile US, "Going IPv6-only", 2018,
<https://pc.nanog.org/static/published/meetings/
NANOG73/1645/20180625_Lagerholm_T-
Mobile_S_Journey_To_v1.pdf>.
[US-CIO] The CIO Council, "Memorandum for Heads of Executive
Departments and Agencies. Completing the Transition to
Internet Protocol Version 6 (IPv6)", 2020,
<https://www.cio.gov/assets/resources/internet-protocol-
version6-draft.pdf>.
[US-FR] Federal Register, "Request for Comments on Updated
Guidance for Completing the Transition to the Next
Generation Internet Protocol, Internet Protocol Version 6
(IPv6)", 2020, <https://www.federalregister.gov/
documents/2020/03/02/2020-04202/request-for-comments-on-
updated-guidance-for-completing-the-transition-to-the-
next-generation>.
[Vrzn] Verizon, "Verizon Digital Media Services announces IPv6
Compliance", <https://www.verizondigitalmedia.com/blog/
verizon-digital-media-services-announces-
ipv6-compliance/>.
[W3Tech] W3Tech, "Historical yearly trends in the usage statistics
of site elements for websites", 2021, <https://w3techs.com
/technologies/history_overview/site_element/all/y>.
[WIPv6L] World IPv6 Launch, "World IPv6 Launch - Measurements",
2021, <https://www.worldipv6launch.org/measurements/>.
Appendix A. Summary of Questionnaire and Replies for network operators
A survey was proposed to more than 50 service providers in the
European region during the third quarter of 2020 to ask for their
plans on IPv6 and the status of IPv6 deployment.
40 people, representing 38 organizations, provided a response. This
appendix summarizes the results obtained.
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Respondents' business
Convergent Mobile Fixed
Type of operators 82% 8% 11%
Question 1. Do you have plan to move more fixed or mobile or
enterprise users to IPv6 in the next 2 years?
a. If so, fixed, or mobile, or enterprise?
b. What are the reasons to do so?
c. When to start: already on going, in 12 months, after 12 months?
d. Which transition solution will you use, Dual-Stack, DS-Lite,
464XLAT, MAP-T/E?
Answer 1.A (38 respondents)
Yes No
Plans availability 79% 21%
Mobile Fixed Enterprise Don't answer
Business segment 63% 63% 50% 3%
Answer 1.B (29 respondents)
Even this was an open question, some common answers can be found.
14 respondents (48%) highlighted issues related to IPv4 depletion.
The reason to move to IPv6 is to avoid private and/or overlapping
addresses.
For 6 respondents (20%) 5G/IoT is a business incentive to introduce
IPv6.
4 respondents (13%) also highlight that there is a National
regulation request to enable IPv6 associated with the launch of 5G.
4 respondents (13%) consider IPv6 as a part of their innovation
strategy or an enabler for new services.
4 respondents (13%) introduce IPv6 because of Enterprise customers
demand.
Answer 1.C (30 respondents)
On-going In 12 months After 12 months Don't answer
Timeframe 60% 33% 0% 7%
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Answer 1.D (28 respondents for cellular, 27 for wireline)
Transition in use Dual-Stack 464XLAT MAP-T Don't answer
Cellular 39% 21% 4% 36%
Transition in use Dual-Stack DS-Lite 6RD/6VPE Don't answer
Wireline 59% 19% 4% 19%
Question 2. Do you need to change network devices for the above
goal?
a. If yes, what kind of devices: CE, or BNG/mobile core, or NAT?
b. Will you start the transition of your metro or backbone or
backhaul network to support IPv6?
Answer 2.A (30 respondents)
Yes No Don't answer
Need of changing 43% 33% 23%
CEs Routers BNG CGN Mobile core
What to change 47% 27% 20% 33% 27%
Answer 2.B (22 respondents)
Yes Future No
Plans for transition 9% 9% 82%
Appendix B. Summary of Questionnaire and Replies for enterprises
The Industry Network Technology Council (INTC) developed the
following poll to verify the need or willingness of medium-to-large
US-based enterprises for training and consultancy on IPv6
(https://industrynetcouncil.org/).
54 organizations provided an answer.
Question 1. How much IPv6 implementation have you done at your
organization? (54 respondents)
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None 16.67%
Some people have gotten some training 16.67%
Many people have gotten some training 1.85%
Web site is IPv6 enabled 7.41%
Most equipment is dual-stacked 31.48%
Have an IPv6 transition plan for entire network 5.56%
Running native IPv6 in many places 20.37%
Entire network is IPv6-only 0.00%
Question 2. What kind of help or classes would you like to see INTC
do? ( 54 respondents)
Classes/labs on IPv6 security 66.67%
Classes/labs on IPv6 fundamentals 55.56%
Classes/labs on address planning/network conf. 57.41%
Classes/labs on IPv6 troubleshooting 66.67%
Classes/labs on application conversion 35.19%
Other 14.81%
Question 3. As you begin to think about the implementation of IPv6
at your organization, what areas do you feel are of concern? (54
respondents)
Security 31.48%
Application conversion 25.93%
Training 27.78%
All the above 33.33%
Don't know enough to answer 14.81%
Other 9.26%
Authors' Addresses
Giuseppe Fioccola
Huawei Technologies
Riesstrasse, 25
Munich 80992
Germany
Email: giuseppe.fioccola@huawei.com
Paolo Volpato
Huawei Technologies
Via Lorenteggio, 240
Milan 20147
Italy
Email: paolo.volpato@huawei.com
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Nalini Elkins
Inside Products
36A Upper Circle
Carmel Valley CA 93924
United States of America
Email: nalini.elkins@insidethestack.com
Jordi Palet Martinez
The IPv6 Company
Molino de la Navata, 75
La Navata - Galapagar, Madrid 28420
Spain
Email: jordi.palet@theipv6company.com
Gyan S. Mishra
Verizon Inc.
Email: gyan.s.mishra@verizon.com
Chongfeng Xie
China Telecom
Email: xiechf@chinatelecom.cn
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