If you do not know anything about IPv6, I suggest you read our IPv6 introductory post that explains the basics. Only that much: The current system, IPv4, has reached its limits IP address wise. This basically means that there are not enough IP addresses available anymore for the continued growth of the Internet and its infrastructure. IPv6 changes that by making available a much larger address pool.

This new address pool and technology comes at a cost though. Computer systems and devices in the world need to be compatible with IPv6 so that they can stay connected to the Internet. There will be a transition period where both protocols run side by side. Eventually though, IPv6 will take over.

The Internet Society has now announced that June 6, 2012 is the official World IPv6 launch day.

Major Internet service providers (ISPs), home networking equipment manufacturers, and web companies around the world are coming together to permanently enable IPv6 for their products and services by 6 June 2012.

Organized by the Internet Society, and building on the successful one-day World IPv6 Day event held on 8 June 2011, World IPv6 Launch represents a major milestone in the global deployment of IPv6. As the successor to the current Internet Protocol, IPv4, IPv6 is critical to the Internet’s continued growth as a platform for innovation and economic development.

Participants include website operators like Facebook, Google, microsoft and Yahoo, network operators like ATT, Comcast, Time Warner Cable or XS4ALL, and home router manufacturers D-Link and Cisco. Participating ISPs will enable IPv6 by default for new subscribers. They have furthermore agreed that at least 1% of their subscribers on their “networks will be using IPv6 when they visit websites that have enabled IPv6″.

Participating companies and websites will enable IPv6 on their servers so that users can use the protocol to connect to these sites. IPv4 support won’t be discontinued right away though, which means that you can still access those sites even if your systems or Internet Service Providers do not support IPv6 yet.

This day marks the beginning of the end of the IPv4 protocol. The basic idea behind the launch day is to push companies, ISPs and device manufacturers into going forward with the implementation of IPv6.

Do you know if your provider, favorite websites and hardware is already supporting IPv6? Lets discuss in the comments.

The Firefox add-on IPvFox does that in a convenient and comfortable manner. It adds an icon inside the Firefox address bar that indicates whether IPv4 or IPv6 was used to connect to the website.

More interesting than that is the list of all connections the web page made to load data. The list includes at least one server, the server the web site is hosted on, and usually a couple of additional servers.

Those servers can be content delivery networks, advertising networks, social networking buttons, third party scripts among other things.

The A Tech Girl’s Life web blog for instance makes two connections. One to the web server the site is hosted on, the other to the web analytics server Google Analytics.

Both the domain name or host name, and IP address are displayed in the listing. The connection data is selectable, which means that you can copy it to the clipboard or a service on the Internet that verifies servers and IP addresses like Virus Total.

I personally would find it more helpful if the add-on would indicate the number of connections made in the address bar directly, instead of the IPv used. Options to export the information directly would also come in handy.

Firefox users can install the IPvFox extension from the official Firefox add-on repository. The add-on requires no restart after the installation or uninstallation.

Ghostery is a similar add-on. The core difference is that IPvFox displays all connections, while Ghostery concentrates on advertising and privacy related connections.

The current Internet addressing system, IPv4 has almost run out of addresses as its designers never anticipated the explosion of the Internet in the way that it’s happened.  So many websites, Internet connected devices and smartphones have joined the Internet in recent years that the switch to a new addressing system has become critical.

Currently, many Internet systems are using ‘ghost’ IPv4 addresses to help cope with demand.

World IPv6 day is a technical exercise to see how, and how effectively the technology works.  All modern web browsers and operating systems have been ready for IPv6 for a few years, but it’s taken enormous effort on the part of technology companies and Internet Service Providers to roll the system out.

For those users already connected to the web via IPv6 systems, they will be automatically directed to the participating websites through the the new system.

Experts have been at some pains to say that despite the problems facing IPv4 saturation this is not a Y2K moment when planes will fall out of the sky.  “The web will continue to work, but future growth would be stymied. It is just like when we used up the phone numbers in London.”

Assuming todays trial is successful, this will act as a catalyst to encourage other companies to roll-out IPv6 infrastructure during 2012.

An IPv6 address has a few differences from IPv4. The first is that it is in hexadecimal instead of decimal. The second is that it is split up into larger segments and more of them. The third is that it uses colons (:) rather than periods (.) to divide these segments. In the end, one does not resemble the other. This is good because it prevents confusing the two.

Hexadecimal is better than decimal for a few reasons. For one, it takes up less space. The number “255″ is “FF” in hex; that is %50 smaller. Hexadecimal also relates more closely to binary. The number “1111″ is “15″ in decimal but “F” in hex. So “11111111″ is “FF” in hex, which is a much cleaner conversion than “255″ is. The downside is that humans typically think in decimal, so working with hex takes some getting used to.

IPv6 has a much larger address size. It has eight sections to it. IPv4 had half of that. The sections themselves are larger too: each one has four digits. IPv4 could only have three, and that only went to 255 tops. It should be obvious why this new address can afford all the room we have come to need. Hopeful it will for a long time. Here is a sample address.

FF00:00FF:0000:0000:0000:02f3:0000:0001

At this point, you may begin to see the down side to IPv6: it is long and hard to remember. To make them more human readable, there are a few conventions to short address when you have a lot of zeros present. First of all, you can skip leading zeros, so “0001″ becomes “1″ and “02f3″ becomes “2f3″ (IPv4 did this too). Second, groups of all zeros can be abbreviated to “::” (a double colon) once; you put nothing there. That makes “:0000:0000:0000:” reduce to “::” but “:0000:” cannot as it would be ambiguous. You can apply the first rule, making it “:0:” now. Putting all these rules into place gives us the following address.

FF00:FF::2f3:0:1

This address is about as long as an IPv4 number. Notice how the “00FF” shrank to “FF” and the “FF00″ did not. That was done intentionally to show the difference between leading and trailing zeros.

There is one more thing you really need to know if you are working with IPv6. The loop-back address, which was 127.0.0.1 in IPv4, is ::1 now. It works exactly the same way. You will have to use the ping6 command in Windows or Linux, so ping6 ::1 is what you would type into the command line. This will give many XP users an error as IPv6 may not be enabled on your computer. We have guides on how to enable IPv6 in XP, and how to assign IPv6 addresses in Linux.

Some other factoids about IPv6 are that it has is easier to route, more secure, and works better with mobile technology. There are changes to the way the packets of information are sent that makes it more efficient (e.g. better headers). It is more secure because it requires the use of IPSec, which is only optional in IPv4. IPv6 has an address recovery system, so when you change locations, it tries to keep the same address. These are are some of the that US government is switching over to it.

I should note that IPv6 has been found to have vulnerabilities. Malware tunneling is described in an article (note: a .pdf file) from the us-cert.gov site. It often has to do with how firewalls are configured. Different sources may give different opinions on how secure IPv6 is.

Wondering what happend to IPv5? It did exist. It was developed in the 1970′s to be used in audio and video streaming. It was called the Internet Stream Protocol. It did not get far past the experimental stage and was never adopted. Ideas from it helped to form IPv6.

It is probably a good idea to test if IPv6 is already available on the operating system. An easy option to find out is the ipconfig command which displays network information in a command line window. To run the command press Windows-R, type cmd and hit enter. This opens the Windows command prompt. Now use the command ipconfig to find out if IPv6 is available on the computer. Please note that the following screenshot is showing ipconfig on Windows 7.

If you do not see an entry IPv6 Address in the listing it is not enabled and needs to be installed. The easiest way to install the IPv6 protocol under Windows XP is from the command prompt. Enter the following commands separately and press return after each of them:

• netsh
• interface
• ipv6
• install

This installs IPv6 under Windows XP. It is also possible to install the protocol under the network settings options of the Control Panel. Right-click on the appropriate network adapter and select Preferences from the selection. Now select Install on the screen and then Protocol from the available options. Locate Microsoft TCP/IP Version 6, a click on OK installs the selected protocol.

1. Open Network Connections
2. Right-click any local area connection, and then click Properties.
3. Click Install.
4. In the Select Network Component Type dialog box, click Protocol, and then click Add.
5. In the Select Network Protocol dialog box, click Microsoft TCP/IP version 6, and then click OK.
6. Click Close to save changes to your network connection.

You can check again with the ipconfig command to make sure that the IPv6 protocol was installed successfully on the operating system.

IPv6 offers a larger address space. The move from IPv4 to IPv6 is difficulty as it requires a coordinated effort from all parties including Internet users. Users with improperly configured computers may experience slowdowns, timeouts or other connectivity issues when the Internet moves to the IPv6 protocol.

Will you have troubles? You can find out if you run the IPv6 test. The test is an Open Source script that runs using JavaScript. Just visit the website http://test-ipv6.com and wait until the test has finished. The IPv6 test runs a series of tests including the browser’s IPv4 and IPv6 capabilities, IPv4 and IPv6 connectivity with and without DNS records and a test that checks if the ISP’s DNS server uses IPv6.

A click on test data reveals details about the tests.

Another click on Technical Info leads to a page that offers technical information about each test which may provide clues to troubleshoot the issue.

The most important test at this point in time for the majority of users is the dual stack test. There will be a transition period where websites and services can be reached via IPv4 or IPv6. The user’s computer now needs to pick one of the protocols and use it for the connection which means that devices that only support IPv4 at this time can still connect to the websites. Connectivity issues occur if this is broken.

Major services and websites will switch to IPv6 for a 24 hour period on World IPv6 day on June 8. Among them Google, Facebook and Yahoo. That’s where the dual stack DNS record support can be tested in a life environment.

It’s been widely reported that the Internet is rapidly running out of addresses using the existing addressing system, IPv4.  The estimate is that the current pool of addresses will run dry in November this year.  IPv6 has been around now for a few years but has never been implemented on a global scale.  The new system would give the world enough addresses to last many years to come.

“The good news is that internet users don’t need to do anything special to prepare for World IPv6 Day” said Lorenzo Colitti, a network engineer at Google.  ”Our current measurements suggest that the vast majority (99.95%) of users will be unaffected. However, in rare cases, users may experience connectivity problems, often due to misconfigured or misbehaving home network devices.”

The IPv6 day is being co-ordinated by the Internet Society which is a not-for-profit group that help educate individuals and businesses about Internet issues.

The aim is that all companies that sign up to the test will make all their pages available on the IPv6 system so that tests can be conducted and problems can be ironed out.  Both Google and Facebook already offer IPv6 sites.

“By providing an opportunity for the Internet industry to collaborate to test IPv6 readiness we expect to lay the groundwork for large-scale IPv6 adoption and help make IPv6 ready for prime time.” said Leslie Daigle, chief Internet technology officer at the Internet Society in a statement.

In November 2010 Vint Cerf, one of the fathers of the internet, warned that the net faced “turbulent times” if it did not move quickly to adopt IPv6.

Now one of the fathers of the Internet, Vint Cerf, has said there’s a chance the switch to the new system could cause several years of “instability” as each country takes its time to make the switch.

In a report by the BBC, Cerf admitted that the change “has to happen or the Internet will stop growing or will not be growable.” as the IPv4 system only allows for about 4.3 billion addresses.

It’s slow work though, search giant Google admitted it took three years to get its own IPv6 network online.  ”The business community needs to understand that this is an infrastructure they are relying on and it needs to change for them to continue to grow and to rely on it,” Mr Cerf said.

The puts the predicted instabilities down to the fact that the two systems are not compatible with one another and that, essentially, the whole world must be ready to make a simultaneous switch if problems are to be avoided.

Some countries including China have made great strides already in their infrastructure switch to IPv6 though some other countries have barely or even not started at all.  Currently only 1% of all Internet traffic is sent via IPv6 and time is running out to get the remaining 99% online.

Of course you will have to have a kernel that is compiled with IPv6 support. Most modern Linux distributions already have this built in. You also have to have your IPv6 addresses handy. I use this simple web-based IPv6 calculator. With that tool select the IPv4 to IPv6 conversion and you should be good to go. So with everything in hand, you are ready to configure.

IPv6 support

First make sure your kernel supports IPv6. To do this you can first run the command:

sudo lsmod|less

and search the listing to see if ipv6 is there. If not try loading it with the command:

sudo /sbin/modprobe ipv6

Now issue the lsmod command to see if it is there. It should be.

Configuration

The file you want to configure will be the standard network interface configuration. Remember you are going to configure for static IP addresses. The file in question is /etc/network/interfaces. Most likely this is either not configured (if you are using DHCP) or set up for IPv4. We are going to blow that away now. We are also going to add something to this file that will ensure IPv6 is loaded properly and that your networking us making use of the new address scheme.

The details of our configuration:

IPv4 address: 192.168.1.10

IPv6 Address: 2002:c0a8:10a::

IPv4 gateway: 192.168.1.1

IPv6 gateway: 2002:c0a8:0101::

Now let’s add this to the /etc/network/interfaces file. The new file will look like this:

#IPV6 static configuration
iface eth0 inet6 static
pre-up modprobe ipv6
address 2002:c0a8:10a::
netmask 64
gateway 2002:c0a8:0101::


Notice the “pre-up” command. That is where we ensure that IPv6 is added to the kernel, otherwise you run the risk of attempting to use an IPv6 address in a system that is looking for an IPv4 address.

Now you will want to restart networking with the command:

/etc/init.d/networking restart

You should now have an IPv6 address enabled.

Testing

Before you assume everything is working, let’s make sure first. You can check your IP routing with the command:

ip -6 route show

The above command should return something like:

2002:c0a8:0100/64 dev eth0 proto kernel  scope  link src 2002:c0a8:10a

You can also check by pinging with the ping6 tool. A good IPv6 address to try is the Google address. Issue this command:

ping6 ipv6.google.com

If IPv6 isn’t working you will get error:

Network is unreachable

If IPv6 is working you will see the standard ping results in your terminal window.

Final thoughts

It’s only a matter of time before IPv6 is the defacto standard for network addressing. When that happens you do not want to be behind the curve or you’ll lose out fast. Make sure you know how to configure your Linux servers for IPv6 static addressing. You’ll be glad you do when the time comes.

Some services offer free SSH accounts, to edit and access files anywhere, host websites, use them as proxies (or IPv6 gateways) and some even let you run processes like IRC bots and compilers.

Generally, such free Shell accounts impose a monthly bandwidth quota of a few megabytes, so you don’t use too much of their resources. Some providers are more generous than others, though, and some charge for additional space and bandwidth.

Most SSH providers offer Unix-based hosting. Mitja Sladovic offers a very large list of such free providers.

The most popular service is the SDF Public Access UNIX System, established in 1987. Free users are offered email hosting (POP or IMAP), games, access to the text-based ‘Lynx’ web browser, web hosting, various network utilities and 80MB space. For access to gcc, php etc., one must pay a one-off fee of $36. In order to validate your account, and receive access to network utilities, one must send them $1 or €5 (in order to deter spammers).

Blinkenshell is another interesting option. Free accounts get 50MiB of space, access to several compilers, an IPv6 tunnel, hosting, email, IRC access and even the ability to have MySQL databases. One can’t use Blinkenshell for IRC bots, though. A few services do provide access to eggdrop, a popular IRC bot, such as Polarhome and aeshells.

Naturally, novices may struggle with such services as no graphical interface is provided. These services do, however, provide a rapid way to compile applications on different platforms (like Linux and BSD) and allow boring processes, like IRC bots, to run for you.

Update: Freeshell is still the number one destination for free remote SSH accounts.