World IPv6 Day

Posted on June 7, 2011

June 8 (Wednesday) is World IPv6 Day. On this day, Google, Facebook, Yahoo, and others will enable IPv6 on their websites.

What is IPv6?

IPv6 is the newest version of the Internet Protocol. Although much software and hardware has IPv6 support, less than 1% of internet users actually can establish a native connection to any given host. Most connections use IPv4, the previous version.

I’m still a novice myself, so I’ll point you to other, better-written articles:

It’s worth understanding IPv6 because it will eventually replace IPv4. All 4 billion addresses in IPv4 have been allocated, so it’s only a matter of time before new computers/devices are forced to have an IPv6 address only.

Hurricane Electric has a “certification” page where you can learn about and test your knowledge of IPv6.

Differences in IPv6

In addition to the larger address size, there are many other differences from IPv4, including:

  • IPv6 does the same thing as IPv4 (route network traffic), but they are basically incompatible and independent from each other. Except in cases of IPv4<->IPv6 translation, the only thing they share is their name.
  • IPv6 uses a different notation. Instead of, for example, an IPv6 address includes hexadecimal numbers, is separated by colons, and is naturally longer — for example, 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
  • IPv6 is a “global unicast” protocol — you can theoretically communicate with any other device on the internet using its IPv6 address.
  • Network address translation (NAT) is no longer needed. However, the inherent firewall in NAT is then gone, so your computer or network needs an IPv6-enabled firewall. The IETF is considering an IPv6 NAT specification so there can be a built-in capability for firewalling and private addressing / services, but don’t hold your breath.
  • DHCP is no longer needed for address allocation — IPv6 has autoconfiguration. However, you might still need a DHCPv6 server (also completely different from DHCP) to advertise the DNS servers. DHCPv6 is not supported on OS X or Windows XP.
  • DNS has a record type called AAAA (quad-A) for IPv6 lookups. For reverse lookups, you still use PTR records (but in a different format).

World IPv6 Day

World IPv6 Day is a chance to see a large-scale deployment of IPv6 and raise awareness, since the tech community has been slow to adopt it. It’s also a chance to see what kind of problems arise, since IPv6 is incompatible with IPv4.

The 24-hour switch starts at midnight UTC, or 7pm on Tuesday for those of us in the Central US timezone.

More about the day:

IPv6 will be running simultaneously as IPv4 on these sites (dual stack), so the vast majority of users won’t see any difference. Most computers prefer IPv6, but will fall back to IPv4 if necessary.

However, there have been implementation bugs in the past, so a small group of internet users (less than 1%, which could still mean millions of people) may have trouble connecting to these sites. This would appear as either no connectivity at all, or a long delay as the computer waits for the connection to time out before switching to IPv4.

Here is more information about preparing:

Transitioning to IPv6

Obviously it makes sense to help customers make their networks and systems be IPv6-ready. A small office network would be a good place for experimenting and testing.

More about transitioning:

Note that because IPv6 is so different from IPv4, there are different versions and tools for working with it — for example, ping6.

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