IPv6 Tutorial: Understanding IPv6 Transition In Three Easy Steps

IPv6 implementation of IPv6 is still less than one percent

Like a dangerous intersection that has existed for years, sometimes it takes a death or other tragic warning to spur people to action. Such a warning came earlier this year, when the last of the top-level IPv4 addresses were issued.

Now it's time to begin the migration to IPv6, which is a separate, parallel network that's incompatible with IPv4. The good news is that we'll probably never have to do this again, since the 128-bit standard provides far more addresses than the planet Earth could even house (the actual number is 340 undecillion, or 3.4 x 10 to the 38th power).

And there's even more good news. In some cases, the technologies that have helped to stave off this impending doom can now be helpful for making the switch. Network address translation, or NAT, issues "private" IP addresses to the IP devices within an organization and keeps track of their communications with the internet through a single, public-facing IP address. With NAT, one public IPv4 address can be used to service many hundreds of IP devices.

So some of your customers that are using NAT might be able to cut over to IPv6 right away, after you help them perform a firmware update and a few settings changes. Whether or not they can cut over immediately depends largely on these three things:

• Is their router and/or NAT-enabled device IPv6 compliant?

• Does their internet service provider offer IPv6 services?

• Are their mission-critical servers running IPv6?

1. The IPv6-compliant NAT

On the surface, the solution provided by the IPv6-compliant NAT sounds like a no-brainer; the NAT does all the work and clients get to keep their existing IPv4 addresses. That's how it works in theory, but this introduces a new problem: there are about a dozen methods currently in use for translating IPv4 to IPv6 and back again.

The two major methods are Teredo, developed by Microsoft, and a specification called6to4 that is backed by Apple, Cisco, D-Link, Fortinet, Netgear and others. Both are meant as temporary solutions while companies transition to native IPv6 networks.

Teredo works by creating tunnels between IPv6 hosts and encapsulating IPv6 traffic as IPv4 UDP messages for traversing IPv4 NATs. It also can assign addresses and work from either side of a NAT.

Unlike Teredo, 6to4 works without the use of tunnels, instead employing a series of relay servers (already in place) to encapsulate IPv6 packets as IPv4 packets to be transmitted over IPv4 networks. It does this by assigning a block of IPv6 addresses to networks with a global IPv4 address. This method permits 6to4 networks to interoperate with native IPv6 networks.

2. Internet Service Provider

The availability of IPv6 service depends entirely on the service provider. Many cable companies have already made the switch and will provide customers with access to their IPv6 servers and addresses immediately. This would enable sites with IPv6-compliant routers and NATs to make the change fairly seamlessly, as long as requirement number three is fulfilled.

3. Mission-critical servers

Some Web-based application providers including Google and Microsoft are already running both stacks on their servers, and can therefore service both types of networks right now. It's important to whether your customer's mission-critical service providers are on board with IPv6 or plan to.

Remember, IPv6 NAT is meant to provide a transition step toward full IPv6 implementation. There are serious downsides to remaining with a methodology that employs network address translation, including an increase in management complexity, the resulting network performance overhead, and the persistence of a redundant network channel that's required by NAT.

Once past the migration hurdles of implementing a native IPv6 network, the paybacks will be huge. The protocol permits the permanent assignment of IP addresses, which greatly simplifies the creation and maintenance of networks and networking infrastructure.

When using IPv6, the client and server communicate directly, eliminating the latencies now endured when server requests are processed through numerous routers, NATs, table look-ups and proxies. Performance improvements can be as much as 10-fold. The end-to-end nature of IPv6 also speeds up streaming applications, and enables on-demand IPsec between client and server, increasing application security and further reducing compute overhead.

With the better part of a million Android and iOS devices being activated each day, many seeking access to the World Wide Web, the time is now for the world to widen its Web.