Archive for March 16th, 2011

Google, Facebook & Yahoo commit to ‘World IPv6 Day’ trial

Several of the Internet’s most popular Web sites – including Facebook, Google and Yahoo – have agreed to participate in the first global-scale trial of IPv6, the long-anticipated upgrade to the Internet’s main communications protocol known as IPv4.


The trial — dubbed “World IPv6 Day” — requires participants to support native IPv6 traffic on their main Web sites on June 8, 2011. Leading content delivery networks Akamai and Limelight Networks also committed to the IPv6 trial, which is being sponsored by the Internet Society.

“It’s an exciting opportunity to take IPv6 for a test flight and try it on for a full 24 hours,” says Leslie Daigle, the Internet Society’s Chief Internet Technology Officer. “Hopefully, we will see positive results from this trial so we will see more IPv6 sooner rather than later.”

IPv6 is a necessary upgrade because the Internet is running out of IP addresses using the 30-year-old IPv4 standard.

BY THE NUMBERS: The Evolution of the Internet

Less than 5% of IPv4 addresses are left unallocated to the regional Internet registries, which in turn dole them out to network operators. Experts say the free pool of IPv4 addresses will be depleted in a matter of weeks.

IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet. IPv6, on the other hand, uses 128-bit addresses and supports a virtually unlimited number of devices – 2 to the 128th power.

When World IPv6 Day occurs, there’s likely to be a surge of IPv6 traffic across the Internet. Today, IPv6 represents less than one-twentieth of 1% of overall Internet traffic, according to Arbor Networks.

One issue is whether IPv6 will be up to the task of providing production-grade performance on such heavily trafficked sites.

The Internet Society estimates that a minority of Internet users – 0.05% – will experience slowdowns or have trouble connecting to participating Web sites during the trial because of misconfigured or misbehaving network equipment, primarily in their home networks.

“There may be some individual hiccups for some small access providers or users, but IPv6 is not an experimental technology,” Daigle says. “I do believe it will work.”

The day-long IPv6 trial is a critical development for content providers such as Google and Facebook, which until now have been supporting IPv6 at separate, dedicated Web addresses rather than on their main traffic-heavy Web sites. Google, for example, says it will enable IPv6 on its main Web sites – including and – for World IPv6 Day.

The event is also a big deal for Yahoo, which has been reluctant to support IPv6 because of concerns about using a DNS whitelisting approach like Google’s, which provides IPv6 content only to users with known end-to-end IPv6 connectivity.

“Participating in World IPv6 Day will allow us to obtain real-life data that we can use to ensure a seamless user experience as we transition to IPv6,” said Adam Bechtel, vice president of Yahoo’s Infrastructure Group, in a statement. “We welcome this opportunity to collaborate with the technical community and provide leadership in addressing the scaling challenges facing the Internet.”

What is IPv6?

IPv6 stands for Internet Protocol version 6. It is the second version of the Internet Protocol to be used generally across the virtual world. The first version was IPv4. IPv5 was a protocol of a different sort, intended to support video and audio rather than all-purpose addressing. IPv6 is also known as IPng, which stands for IP Next Generation.

One of the main upgrades in IPv6 is in the number of addresses available for networked devices. For example, each mobile phone or other kind of electronic device can have its own IPv6 address. IPv6 allows 3.4×10^38 addresses. This is mainly due to the number of bits in each protocol. IPv4 addresses have 32 bits in them and so allow a maximum of four billion addresses. IPv6 addresses have 128 bits.

However, IPv4 is still the protocol of choice for most of the Internet. The transition will be a steady one, and IPv6 is the future of Internet addressing, mainly because industry experts believe that they are close to running out of available addresses altogether.

Another example of an IPv6 upgrade is multicasting, which is standard in IPv6 but only optional in IPv4. Multicasting is delivering a data stream to multiple destinations at the same time, with no duplication unless called for. Those functionalities are not supported by IPv4. The other two types of addressing that are standard practice for IPv6 are unicast and anycast. The former is a transmission from just one host to just one other host; the latter is from one host to the nearest of many hosts.

IPv6 also has two other significant advantages over IPv4. IPv6 offers a higher level of built-in security, and it has been specifically designed with mobile devices in mind. The security comes in the form of IPsec, which allows authentication, encryption, and compression. The mobility comes in the form of Mobile IP, which allows roaming between different networks without losing an established IP address. Both of these functionalities are requirements of IPv6 and so are designed to be built into every IPv6 stack, address, and network.


IPv6 to IPv4 Problems


Broken IPv6 connectivity is often caused by 6to4 tunnels that don’t work. 6to4 is a system whereby a computer or a home gateway can create IPv6 addresses from an IPv4 address and connect to the IPv6 Internet by encapsulating IPv6 packets inside IPv4 packets. A remote gateway then decapsulates the packets and encapsulates the packets in the other direction. The problem with 6to4 is that it depends on gateways operated by volunteers. Those gateways may work very well, be slow, or not work at all. And some ISPs don’t bother delivering their user’s packets to a gateway.

6to4 is only enabled if the system has a public IPv4 address. Places that give their users public IPv4 addresses, such as many universities, tend to use firewalls, which often filter out the IPv6-in-IPv4 packets. So broken 6to4 is not uncommon. However, after a recent Mac OS X 10.6 update, pretty much all operating systems prefer to use IPv4 over 6to4 IPv6 so broken 6to4 shouldn’t cause any problems if there is still working IPv4.

The Internet Society expects that on IPv6 day, 0.05 percent of all users will see problems. With a billion unique visitors, that’s still half a million people. If your job is phone support for one of these companies or an ISP, you may want to get your vacation request in as soon as possible. The advantage of many large Web destinations enabling IPv6 on the same day is that everyone will be on the lookout for IPv6-related problems, so those can be fixed quickly. If you don’t want to wait that long, visit to evaluate your readiness.

At this point, it’s hard to predict what this experiment could mean for the amount of IPv6 traffic that flows through the Intertubes. If a lot of users are IPv6-enabled, a good amount of traffic can move from IPv4 to IPv6 overnight. This depends on how many additional sites and networks join the effort, though.

In the meantime, on Monday, APNIC, the registry that gives out IP addresses in the Asia-Pacific region, got two more blocks of 16.78 million IPv4 addresses from IANA. APNIC burned through no less than 23.7 million in January—twice as much as their monthly rate in 2010. There’s only five blocks left now. These final five are expected to find a home on Thursday morning during a webcast ceremony in Miami.

Oh, and what happens when World IPv6 Day is over?

They turn IPv6 off again. Considering the fact that we’re scraping the bottom of the IPv4 barrel right now, and APNIC may even be clean out of addresses by June, maybe the Internet Society should reconsider that part of the plan.