November 15, 2007
By Janna Quitney Anderson, Director of Imagining the Internet and Assistant Professor of Communications, Elon University
Rio de Janeiro, Brazil –Every time you communicate on the Internet – sending or receiving information – you follow a protocol. Well, you don’t, exactly, but the messages you send when you seek a Web page or send an e-mail do. It is the Internet Protocol, or IP.
The information we seek to send or receive on the Internet must have an address of some sort – just like old-fashioned “snail mail.” Information is sent and received online in packets, and those packets can’t go anywhere without the addresses on either end of the communication. These are known as IP addresses.
No IP address, no information swap.
And, due to the explosion of networked devices in the world, we are going to be running out of IP addresses soon. That is why Internet engineers have developed a system to allow many more addresses.
But the change to the new system is not easy and it is seen as a cost without revenue, so movement to its use has been slow; too slow.
The Internet is a work in progress, constantly being enlarged, enhanced and improved by an international group of dedicated engineers, scientists and technology developers, the Internet Engineering Task Force (IETF). Most of them agree on the following message for the world:
Because the IPv4 address space is approaching full allocation, and because major hosts including Linux, Windows Vista and MacOSX Tiger and Leopard support doing so, we need to turn on IPv6 routing in our IPv4 networks and enable its support in our servers. This will enable a clean transition from IPv4 to IPv6 over the next few years. We will eventually “turn down” IPv4, but few recommend doing this soon.
ARIN, the American Registry for Internet Numbers, which assigns addresses in the U.S., says less than 19 percent of the addresses for IPv4 remain. And other regions of the world have even fewer numbers left to assign. It is estimated that there are only enough addresses to last until 2010.
Under IPv4 there is the possibility for 4.2 billion unique IP addresses. That sounds like a lot, especially since it is estimated that there are just 1.2 billion people using the Internet today – but the expanding universe of Internet-enabled devices (cars, cell phones, appliances, remote-sensing systems) is swallowing them up.
IPv6, which is actually now in limited use in some areas, allows for nearly 340 undecillion (3.4×1038) addresses. This number equates to 340 trillion trillion trillion. Written another way, that is 340,282,366,920,938,463,463,374,607,431,770,000,000 addresses that IPv6 advocates say will obliterate the shortage and also allow for better security and the ability to prioritize data. This data differentiation can improve, for instance, communication during a disaster like Hurricane Katrina or 9/11, allowing the vital messages to get through.
Some people have said that IPv6 is too ambitious and complex; it is a leap from a 32-bit address system to a 128-bit system, why not settle for 64? they ask. The answer is that 64 might not have been enough. IPv6 originally was proposed as 64-bit, but when Internet architects looked at the fact that our future will be one filled with ubiquitous networked objects (“IP on everything” is the projection – imagine everyconsumer item assigned an IP address, not just computers, cars and cell phones), the decision was to plan accordingly.
One scientist who supports the 128-bit system says the number of addresses under IPv6 will equal or surpass the number of grains of sand on the planet. When you start dealing with numbers this high, they are difficult to comprehend and it becomes equally difficult to come up with appropriate ways to make them understandable.
Why haven’t we all been switched over to IPv6? It has had a slow rollout because it is complex, adoption is costly and people need to be motivated to disrupt a comfortable routine or to make a new investment. Most software developers, ISPs and end users don’t see a compelling reason to make the switch to running IPv6 and IPv4 in parallel right now. Migrations to improvements in technology are generally motivated by the introduction of some killer application that everyone desires, and the only headline-grabbing reason for IPv6 is the idea that we will eventually run out of addresses.
“Folks worry about IPv6’s impact on their operational networks,” explained Fred Baker, a leader at networking company Cisco who has also been a leader in most of the major Internet-architecture groups, including the Internet Society and IETF.
“It requires at minimum a software upgrade and, in some cases where older equipment is involved it requires a hardware upgrade, which costs money. If they are going to shell out the money, they want to offset it with revenue. They are also concerned that new software generally has weak points that haven’t been discovered yet. That can sometimes not only impact the new system but also their existing networks.”
Software updates to use IPv6 at the consumer level are generally not going to be necessary. If you are running Vista, Linux or Mac OS X, your computer is already capable of running IPv6 now and doesn’t use it only because your network doesn’t connect the protocol.
Some governments – including those in China, Korea and Japan – have begun to offer incentives and/or set up requirements tied to motivating IPv6 implementation throughout the networks that make up the global Internet, and the European Union is assessing ways in which to encourage its adoption. In the U.S., the government is requiring that the network backbones of all federal agencies must implement IPv6 by 2008.
The U.S. has far more IPv4 addresses left to assign than many other nations, so it lags behind many in the decision to adopt IPv6. Anywhere in the world where there’s a more extreme V4 address shortage IT managers have been working to implement IPv6. The problem is that IPv6 addresses can’t communicate with IPv4 addresses – they are not compatible.
Baker said the end result of global connection makes the investment in IPv6 today worthwhile. “I’ll refer you to Chris Harrison’s Internet density map here. he said, explaining that the map displays the relative densities of Internet connectivity across the planet. “People live in the ‘dark’ places; the dark places tell us we’re not done yet. With 80 percent of the IPv4 address space allocated and that amount of dark space unconnected or minimally connected, we’re not going to succeed without more addresses.”
Vint Cerf, a co-inventor of the Internet Protocol and former chair of the Internet Corporation for Assigned Names and Numbers (ICANN), explained the situation at the Internet Governance Forum.
“The IPv6 addresses are meaningless unless they show up in a routing table somewhere [IPv4 ignores IPv6],” he said. “The inability to reach everywhere in the Internet with the new address space is a serious barrier. When you implement V6, unless you connect with another IPv6 network, you may actually be an island of IPv6 operation.”
Cerf said it is vital to adopt policies to encourage all Internet service providers to allow connectivity. “Governments could choose to subsidize the cost of inter-exchange points that would encourage interconnection using IPv6 address space so as to reach as quickly as possible a fully connected IPv6 system in parallel with the IPv4 system,” he said.
The Internet began in the 1960s as a connection between just two and then just a few computers in the United States. It was a simple thing at first for the engineers and computer scientists who built the Internet to assign addresses. As the network grew, one of them, Jon Postel, established the Internet Assigned Numbers Authority (IANA), which later began to be operated under the auspices of ICANN.
IANA assigns blocks of IP numbers to the Regional Internet Registries (RIRs) like ARIN, each of which distributes IP addresses in various areas of the world. Because IPv4 numbers are in short supply, the assigning of blocks of V4 numbers becomes extremely political. Introducing IPv6 everywhere would help relieve a great deal of the political pressure.
When IGF participant Alain Durand asked Vint Cerf, “What can we do?” Cerf replied, “If you go to Internet service providers and say to them, ‘I want to provide my content on IPv6. What can you do for me? What kind of access can you give me? And, oh, by the way, what reach do I have? How well can I touch the rest of the Internet using IPv6?’
“If more of us in the community that consume Internet services or provide Internet services through the ISPs went to them and said, ‘I now need IPv6 as well as IPv4,’ it might persuade them that they need to supply it. Right now, they’re not convinced because they’re not hearing very much demand. I urge you to raise the issue with as many ISPs as you are able to.”
IPv6 has a few critics. Some have expressed concerns that the larger header size of the IPv6 addresses will slow effective transmission rates. They also say the interface in this address system is trackable even in a mobile system, which raises privacy concerns. But Baker says computer security experts have used IPv4 addresses to track down stolen network interface cards (these are called NICs – every computer has a card with a unique address), so the tracing capability is present in today’s networks already. “There are also other problems, notably in routing, that IPv6 doesn’t address and critics wish it did, but the security and quality-of-service discussion surrounding IPv6 is mostly hype,” he added.
Nobody can estimate the cost of the transition to IPv6, which requires some intense updating of applications to support the increased address lengths. For instance, IPv6 readiness is already built into some software, including some desktop and server operating systems, but most Internet content and services are still structured to be incompatible with IPv6. And Internet service providers (companies like as Earthlink and AOL) have to make changes so firewalls, management, monitoring and other systems are compatible with IPv6 before its addresses will work.
But no matter what the arguments or complications are at this point, the fact is the Internet is mostly operating on IPv4 now and it must be transitioned to running IPv6 in parallel at a faster rate than it is at this point. An overnight switch of a significant proportion would raise problems, so the people who build and operate the Internet are hoping that the transition speed picks up.
“To be clear,” Cerf said, “if we finally exhaust the IPv4 pool it doesn’t mean the Internet stops working, but people wanting an IPv4 address won’t get one. If there is an Internet that does not support IPv6, not getting an IPv4 address means not getting on the net.”
No one wants to see a mad rush to change when we hit “zero” on remaining IPv4 addresses sometime in the next five years, thus individuals in the know and the leaders of governance organizations such as ICANN and IETF are urging the active move to IPv6 now.
“We would like to see IPv6 turned on in everybody’s networks,” Baker said.
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