Announcement regarding IPv4 Address Block 43/8

By on 25 Mar 2020

Categories: Community Development

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Prof Jun Murai presenting to university students. Image credit: Joi Ito

As many people know, I have dedicated much of my career to the development of research networks and network technologies in Japan and Asia. This included the WIDE (Widely Integrated Distributed Environment) Project, founded in 1985 for computer networking R&D. In the early days of the WIDE Project, we were aware of the exciting advent of the Internet, and I was often in contact with Jon Postel and other Internet pioneers, about how it could be brought to Asia.

In the late 1980s, I recognized the Internet’s importance in the world and in Asia. I requested a number of early IPv4 Class B assignments (/16s), directly from Jon Postel as NIC function delegation trial, as well as Class Cs and a Class A, for use by research networks in Japan. Since then, I have been administrating the Class A assignment, 43/8, to assist in the long-term development of the Internet in the Asia Pacific region.

In the early 1990s, I helped to establish APNIC from JPNIC, to provide continuing allocations of IPv4 address space for our region, Asia Pacific, at a time when the Internet was growing very quickly. APNIC launched in 1993 and has been very successful in managing IPv4 address space since then.

Since 1992, I continued to lead the WIDE project, which was then dedicated to the development and promotion of IPv6. Some of the 43/8 address space was used for this purpose, to assist Japanese networks with renumbering in their transition to IPv6. Some of this space, a /11 in total, was allocated by APNIC to participants in that project, and the rest retained by the WIDE project for other R&D activities.

The deployment of IPv6 has been slower than expected, but I’m very happy that finally, IPv6 is in full production around the Internet, and used by around 25% of Internet users globally. It’s clear now that IPv6 will succeed and that the Internet will be greatly improved as the transition continues into the future.

IPv4 has a continuing role on the Internet, but a relatively short-term role, as IPv6 adoption increases. Therefore, IPv4 address space has a current value, but a value that will reduce and disappear over the next 10 years or so. While I have not been an active supporter of the commercialization of IP addresses, the fact is that a market for IPv4 addresses exists and the APNIC community has remained neutral by developing a proper policy framework for market transfers.

In considering the future of 43/8, I have again considered how it may be best used for its original purpose. After careful consideration, I have taken a decision to release this address block, for the purpose of healthy development of today’s Internet services and toward supporting Internet development in the AP region. This is possible by making it available on the IPv4 address market. This is an opportunity to produce a capital asset, with a significant impact on Internet development, if used well and carefully. It is an opportunity that exists today and might not be repeated at any point in the Internet’s future.

As I mentioned, APNIC has now been established for 27 years, and it has performed a critical and successful role. APNIC has served very well as the Regional Internet Registry for our region, and it has had a great impact in the development of the Internet in our region. With the establishment of the APNIC Foundation in 2016, it’s clear that APNIC is committed to the continuation and expansion of that good work.

Recognising APNIC’s role and its successes, I have asked APNIC to receive a transfer of the unallocated portion of 43/8, on two conditions: that the block will be placed on the IPv4 address market for those who still need IPv4 addresses, and that the proceeds be used in support of Internet development in our region. I am grateful that the APNIC Executive Council has accepted this offer and is now proceeding accordingly, with the establishment of a charitable trust (the Asia Pacific Internet Development Trust) to take responsibility for this asset and its disposal on the IPv4 address market.

I will remain closely involved, personally and through the WIDE Project, in the management of the Trust, and in its support of Internet development in our region, primarily through the APNIC Foundation.

I am very happy to have taken this step and am looking forward to the results in the coming years and decades.

I thank everyone involved in this process.

Professor Jun Murai is the founder of the WIDE Project and a professor at the Faculty of Environment and Information Studies at Keio University, Japan.

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The views expressed by the authors of this blog are their own and do not necessarily reflect the views of APNIC. Please note a Code of Conduct applies to this blog.


  1. Tony Smith

    Hi Rao,

    Now that the addresses have been transferred from WIDE Project to APIDT, the Trust will determine the process for the sale of the space, with assistance from KPMG. It’s too early to know the final details, but it is expected that the Trust will offer the addresses for sale on the open market.

    Tony @ APNIC

  2. Abraham Y. Chen

    Dear Prof. Murai:

    0) I am a novice to the Internet. Everyday, I learn something new and intriguing. I admire very much your endurance with the WIDE Project. I have a couple related topics to share and would appreciate your thoughts.

    1) ” … finally, IPv6 is in full production around the Internet, and used by around 25% of Internet users globally. It’s clear now that IPv6 will succeed …. “: You may like to review the below article by Ericsson Research and the discussions that followed. That is, something seems to be quite different from the general impression.

    2) “… IPv4 has a continuing role on the Internet, but a relatively short-term role, as IPv6 adoption increases. … “: Please have a look at a whitepaper below. The proposed RAN (Regional Area Network) configuration may be relevant to the WIDE Project based situations. In fact, with the EzIP (phonetic for Easy IPv4) scheme, one single IPv4 public address may support the entire Tokyo Metro, even without the use of the Private Networks. If the latter is employed as the common practice today, the entire US could get by with just one IPv4 address, based on Cisco projected usage rate.

    3) The above leads to other behind-the-scene intricacies that would deviate from the topic that you started with this blog. So, I should not elaborate here. If interested, allow me to invite you to discuss with me via my contact information available in the above references.

    Thank you.

    Abe (2020-03-25 10:16 EDT)

  3. Tony Smith

    Hi Sindy,

    APIDT published a short update today on this topic:


  4. Alex

    Good article,
    I think IPV6 is the future of the Internet as there is going to be huge number of devices contested too internet using technologies like IoT.


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