Relevance to Theme: This submission is related to the security, safety, stability and resilience theme. It is well known that IPv6 was developed to someday replace IPv4 in Internet communications. However, when this day comes, will we be prepared? In an attempt to maintain the stability of the Internet, most networks nowadays are moving towards operating with both IPv4 and IPv6. According to measurements made by such relevant Internet companies as Google, Akamai and Cisco, more than a quarter of the Internet traffic is already running on IPv6. In fact, those measurements suggest that IPv6 usage may reach around fifty percent in a few years. However, should we wait until it is almost too late for this transition to then start preparing for it? In other words, what should the threshold for IPv6 deployment be to support the shutdown of IPv4: 80 percent, 90 percent, 99 percent, or only when we reach 100%? Answering this question is not an easy task because it will affect all the Internet! If a part of the Internet does not migrate to IPv6 and continues working with IPv4-only, it will be isolated when this shutdown happens. That part of the Internet will be like an island on the network. The Internet users from that island will not be able to communicate with the rest of the Internet and vice versa. Additionally, we could experience exclusion if part of the Internet decides to shut down IPv4 alone. Except that in this case, an IPv6-only island will be created, thus alienating the rest of the world which has not fully deployed IPv6. In other words, a joint effort of all stakeholders is essential to solve this situation. All of them must work together to migrate networks to IPv6-only and decrease and avoid negative effects. Analyzing the issues involved in the transition from IPv4 to IPv6 is the focus of this workshop. This analysis is particularly important because this transition might cause serious troubles for the whole Internet such as isolation, digital alienation, lack of stability and security complications. The Internet is composed by a mesh of connections among autonomous systems (Service provider, Content provider, Transit Provider). If one of these autonomous systems establishes only one protocol (IPv6 or IPv4) to use while others are using the other protocol, it will be apart from the network (an isolated island). Its users would not have access to all services and information available on the Internet, and this would infringe one of the basic Internet Governance principles (that of the freedom of information and access to information). Besides, this island might prove even more serious if it is located in the core of the Internet (Tier 1 or Tier 2). This issue would reduce the amount of paths on the Internet. Packages would have fewer routes to reach their destinations, thus having a negative impact on the stability and resilience of communication causing packet loss and higher latency. In addition, security and privacy issues may happen because of the path reduction. The absence of a safe route can force packages to follow unsafe paths. A parallel can be made with the DNS root KSK rollover process that involved several stakeholders. During the exchange of keys some networks were isolated and their users lost access to the internet. Much of what has been learned can be applied in this migration of protocols. Therefore, it is important to prepare for the moment when IPv4 will definitely stop from being used. Only through a discussion of this problem in a multistakeholder, interdisciplinary and international context, a comprehensive solution will be achieved.

Relevance to Internet Governance: The Internet was created and developed with the Internet governance principles of freedom of association, information and access to information. To achieve these goals services, applications and infrastructure needs to work properly. If one part fails, the whole structure will be compromised. This workshop will discuss the implications that Internet might suffer when disconnecting IPv4, especially if a joint effort with all stakeholders does not happen. For more than 30 years the Internet has used IPv4. However, the amount of free IPv4 public addresses that can be allocated to machines are depleting. According to some studies made by Regional Internet Registries (RIRs), it is expected that in less than 5 years there will be no more IPv4 public addresses to be assigned. In other words, IPv4 needs to be replaced by its successor IPv6. At this moment, networks are concentrating efforts in working with both protocols (IPv4 and IPv6). However, working with both generates a lot of wasted efforts. On the one hand, developers spend their time and energy developing identical functions for the two protocols. On the other hand, network devices share their memory and operations to handle packets of the two protocols. So this is a temporary solution until it is possible to shut down the IPv4. In order to shut down the IPv4, a joint effort with all stakeholders is necessary. Not only to ensure the correct operation of the Internet (including the Internet governance principles) but also to minimize problems that may happen. Especially because, as explained in the text “Relevance to Theme”, islands (IPv4 and IPv6) on the network may appear, causing trouble to stability, security and resilience of the Internet. Each of the stakeholders needs to understand their role in this transition to ensure the least impact on the whole Internet. Internet Services Providers (ISPs) are responsible for providing Internet access to theirs customers. Regardless of the protocol they use (IPv4 or IPv6), they must ensure that their users have access to the entire Internet. If they decide to operate with only one protocol without the help of other stakeholders, they may lose access to part of the Internet. This will violate the principles of Internet governance and will cause a drop in their revenue due to the number of customers that will decline their services. Manufacturers develop network devices to allow users to communicate with a service on the Internet. These devices nowadays need to operate with both protocols, especially because this is a requirement of the current market. If manufacturers develop their devices with no support for a protocol with a demand from other stakeholders, this may lead to a decrease in their sales. The governmental responsibility is to create regulations to guarantee the rights of users and companies that depend on the Internet. However, legislating on which protocol should be used in a country without the support of the rest of the world is a very risky situation. The regulation may cause a digital exclusion of the country besides harming the economy. Many companies can move their operations to other countries because they do not accept the new regulations. Academia, research groups and standards organizations (like IETF) have an important role in disseminating knowledge and developing Internet protocols. As both IPv4 and IPv6 are being used on the Internet, they should not state just one protocol to be taught to the community, as the lack of knowledge of the other protocol can generate a difficulty in finding qualified professionals to meet market demand. Such situation may affect the economy causing an inflation of the prices of products and services on the Internet. Therefore, it is fundamental to bring together different actors involved in migrating protocols to discuss the issue in order to advance comprehension of this problem and identifying possible solutions in order to satisfy different perspectives. Tag 1: IPv6 deployment Tag 2: End of IPv4 Tag 3: Migration from IPv4 to IPv6