A lot of coverage of IPv6 over the past few years gives the impression that you need to switch to IPv6 soon. That's not necessarily the case, though, especially for a consumer or a small business.
Since the late 1970s, Internet Protocol version 4 has been the standard address system for identifying and locating computers, routers and other hardware on the Internet. But as of February, all 4 billion addresses that IPv4 provides have been given out. To fix the problem, a second protocol, IPv6, debuted a few years back, though adoption is not yet widespread.
IPv4 is the original network protocol, initially designed to connect university and government mainframes. Since the number of connected systems has skyrocketed from merely dozens back in the 1970s to billions today, the original protocol had to be reworked to handle more systems than the 4 billion it provided for. IPv6 can support 2128 addresses, or about 3.4x1038 (3,400,000,000,000,000,000,000,000,000,000,000,000,000) devices.
Now that IPv4 addresses are all assigned, the pressure on many organisations to move to IPv6 is growing steadily. Small companies might worry about what the switch will require, but fortunately for most people, it is a good ways off, and it won't be a big deal even when it happens.
NAT can handle the transition
For most homes or small businesses, making the shift to IPv6 doesn't need to have a major impact. Basically the same NAT (network address translation) technology that lets many networks use a single IPv4 address for each office, no matter how many systems they have, will also allow a network to have an "outside" IPv6 address and continue to use the existing IPv4 addresses inside the firewall. The only required change in this case happens at the firewall or router that connects the network to the Internet.
This means that initially you don't need to switch all of the internal devices on your network over to IPv6. Even the US Office of Management and Budget will be using the NAT strategy for most of the federal system at first, converting outward-facing systems to IPv6 in 2012, and then the rest in 2014.
A lot of small businesses will find that their Internet service providers not only lack a deadline for moving to IPv6, but also don't offer IPv6 addresses or services yet.
And a great many small-business-oriented products don't yet support IPv6. For some products, adding such support may require only a software upgrade; many older products may never receive that, however, so new hardware might be necessary to make the switch.
Because IPv6 can add security, increase performance, and offer other advantages such as ease of use and network traffic flow control, it's worth planning for. Generally, though, it's no rush for most small businesses.
A possible exception is if you use Voice-over IP, which may require IPv6 addresses sooner rather than later, depending on the carrier and PBX system. If this is the case, your VoIP service provider should give you substantial advance notice.
Why not switch now?
The reason not to convert all systems at the same time is simple: Many older PCs, network switches, routers, print servers and other network devices may not support IPv6. While a server could run both IPv4 and IPv6, and permit both types of connected devices to talk to one another, this arrangement introduces additional complexity and can contribute to the load on the server. In addition, network administrators will need to switch the setup over, a process that can take at least a few minutes for each device on the network.
Many organisations may not even need to switch at all until their ISP does. The Internet will run both IPv4 and IPv6 for many years to come, and your ISP will translate automatically for you if your network is still using IPv4. If you want to use an IPv6 address for your network, or if your ISP notifies you that it is converting and that you'll need to have an IPv6 address, the conversion process happens in two steps: First, you'll need to get a new address, and second you'll need a router (or firewall/router) that supports IPv6.
The external IP address your network will have is assigned by your ISP and is used by any outside system sending data to your network. You'll need to coordinate with your ISP to obtain this address. The address then needs to be associated with the names of your email, web and other servers, using the domain name service (DNS). Registering an IPv6 address for a domain name can still be complex, and some providers may not have a system in place for that yet.
If your servers are hosted by a third party provider such as GoDaddy or Google, you shouldn't need to worry about IPv6 and DNS. Your service provider should take care of the conversion for you.
Have a new IPv6 address?
Once you have a new IPv6 address, you'll also need a router or firewall that supports IPv6. Such products are still hard to find, especially in less expensive, small business-oriented versions. Cisco and other top tier vendors have IPv6 support, although even there, often the only way to know which products support it is to read the manuals.
Getting IPv6 to work can be tricky, and support is typically difficult to come by. You need to verify that your ISP can support your switchover and your specific router before you even try to upgrade. Ask your provider which router is recommended (D-Link, for one, has a reputation for IPv6 compatibility.) You should also plan on having both an IPv4 address and an IPv6 address for a while, and you should make sure that your ISP supports running both protocols simultaneously.
If you have an IPv6 address, and your router or firewall has IPv6 support, you may not need anything more. The router should be able to translate between your internal IPv4 network and the Internet, and unless or until you need to connect more systems than just an email or web server directly to the Internet, you might not have to make any more changes.
Eventually, when all your PCs are running Windows 7 or later and your servers are running Windows Server 2008 R2 or later, and when all the rest of your network hardware is less than two years old, you may want to consider moving to a completely IPv6 network.
At that point, with each device having its own IPv6 network, you'll gain some substantial advantages, such as the ability to easily and securely access any device on your network from any outside system without special remote access software. However, it may be at least three to five years before the average small business needs to work on this.