At this writing, Internet experts predict that we have less than two years before the exhaustion of IPv4 addresses that fuel the growth of the Internet. Of the 4,294,967,296 addresses available in IPv4's 32-bit address space, we've consumed 90 percent, leaving less than 425 million addresses remaining. That's not a lot, and the rate of consumption is increasing, making it difficult to pin down the actual date the last address will be used.
Alas, trouble will start long before that day arrives, owing to the economics of scarcity and demand. As a resource becomes less plentiful, its price increases, something that has already occurred with IP addresses in North America. Unless an alternative resource—IPv6 addresses in this case—becomes available, the cost of getting a new public IPv4 address could skyrocket.
Fortunately, the IPv6 Internet is alive and well, and waiting for your arrival. We all had a golden opportunity to push an IPv6 migration more than a year ago, before the current economic crash, but few availed themselves of that opportunity. Now, with funds tight and jobs precarious, we're faced with making the IPv6 move on shoestring budgets. Consider this article your shoestring to IPv6. By spending very little money and a modicum of your own time, you can set up an IPv6 lab that will help position you for an IPv6 transition when it becomes unavoidable.
With an IPv6 laboratory at your disposal, you'll gain experience with IPv6 addressing, network troubleshooting, and deployment methods. You'll also have a test bed for validating IPv6 compatibility for current and future applications, hardware, and services. Most importantly, you'll be augmenting your marketable skill set in a way that will make you much more valuable to your employer, current or future.
The Big Picture
In "The Inevitability of IPv6 Part 1" (and Part 2), John Howie explained IPv6 addressing, features, and operation under various versions of Windows. If you're not conversant in IPv6 addressing concepts and terminology, you should review
those articles as a prerequisite to starting this project.
In addition to that technical background, an essential thing to know is that the IPv6 Internet is open for business, populated by the likes of Google, Apple, and Microsoft, and growing at a steady pace. You can get connected to that Internet by a variety of methods: a direct connection from your ISP, a desktop-only connection using VPN tunneling, or a LAN connection via an IPv6 ISP offering tunnel-brokering services. The most useful approach for a lab is the last method, because you get a large IPv6 address space that you can use for actual deployment when you're ready and that you can readily break into subnets for experimental purposes.
The image below illustrates how your lab connects to an IPv6 tunnel broker. The tunnel broker operates one or more IPv6 tunnel servers located around the world. You choose a broker with a server reasonably close to you and sign up for service, which typically costs nothing—the tunnel broker hopes to win your business when you move your entire organization to IPv6. You then set up an IPv6 tunneling router behind your enterprise firewall, which establishes an IP protocol 47, or Generic Routing Encapsulation (GRE), IPv6-over-IPv4 tunnel connection to the tunnel broker and delivers IPv6 connectivity to your IPv6 laboratory network. Protocol 47 is often used for VPN tunnels, but in this case, the tunnel isn't encrypted. It's just used to transport IPv6 packets to your lab network.
A point you should have picked up in your IPv6 prerequisite reading, but worth reiterating here, is that all IPv6 networks are actually a combination of both IPv4 and IPv6 protocols, a configuration termed dual stack. A dual-stack network is necessary because the opportunity to make a clean cutover to IPv6 passed us by years ago. The only transition path left available is for every device to be on both IPv4 and IPv6 networks for the several years it will take to move totally to IPv6. Although more complex than the clean-cut approach, dual stack operation has the advantage of letting you gradually introduce IPv6 into production networks.
It's important to recognize that you'll be routing public IPv6 addresses behind your corporate firewall, so your IPv6 lab network should remain completely isolated for security purposes. The example router configuration provided in this article includes a sample security policy that blocks all inbound traffic except HTTP (TCP port 80). You can modify that policy to suit your experimental requirements.
To make your IPv6 lab operational, you'll have to complete three tasks:
- Sign up with an IPv6 tunnel broker and get an IPv6 IP address allocation.
- Acquire and configure an IPv6 router to use the tunnel.
- Activate and test your IPv6 connection.