InteropNet's IPv6 Plans

One of the more interesting aspects of attending Interop is seeing the demonstrations that the InteropNet team is putting on. At the upcoming show, the InteropNet is running several IPv6-capable networks that are supporting both exhibitors and attendees. This marks the first show since Interop returned its Class A address space to the American Registry of Internet Numbers (ARIN) in 2010. If you are at Interop, check out the various InteropNet locations offering IPv6. I caught up with some of the InteropNet team by phone to talk about IPv6 while they were hot-staging the network prior to the show.

Gunter Van de Velde, senior technical leader, IPv6, with Cisco and chair of IPv6 Council-Belgian Chapter, says, "The good news is that the equipment interoperates extremely well, and the problems with particular operating systems are well-known. We spent a lot more time getting people familiar with IPv6. Once you know it, configuring for IPv6 is no harder than IPv4."

InteropNet is in a somewhat unique position: A new network is built out for every show, meaning there are no legacy equipment restraints nor concerns about growing the network over time. The Interop team sets up and tears down the network in about 45 days. However, InteropNet also has to support a variety of devices from exhibitors and show attendees. You may not have the luxury of being able to create your networks from scratch, but as Van de Velde points out, transitioning to IPv6 provides an opportunity to take what you have learned managing IPv4 and better plan your IPv6 address space along logical lines.

InteropNet's IPv6 addressing is based, in part, on taking the address allocation received from ARIN and mapping existing hexadecimal equivalent IPv4 subnets into the network portion of the IPv6 address. IPv4 subnets and corresponding IPv6 subnets are then run concurrently. IPv6 hosts will either be statically configured (such as critical servers like DNS, syslog, etc.), or hosts will use IPv6 auto-config with EUI-64 to set-up their addressing. EUI-64 conversion expands a 48-bit MAC address to 64 bits by inserting 16 bits "FFFE" between the OUI and NIC portions of the MAC address. EUI64 ensures that the host portion of the IPv6 address is unique during auto-config.

Host addressing will also use stateless auto-config. Auto-config relies on routers sending out router advertisements that provide IPv6 addressing and subnet masks. Auto-config uses the network information sent from the router advertisement and the EUI-64 address based on the hosts' own MAC address to create a full IPv6 address.DHCPv6 is used to tell hosts where critical servers are, such as DNS and network time--something that isn't transmitted in router advertisements. To protect the IPv6 from rogue router advertisements, which are used to create man-in-the-middle situations, RA-Guard, a feature found on many modern IPv6 capable switches, will allow router advertisements only from specific ports and block all the rest.InteropNet is creating three IP networks. The main network will be a dual-stack IPv4/IPv6 network that will be available to exhibitors and show attendees. Scott Leibrand, content delivery network architect with LimeLight Networks, who has worked on several dual-stack IPv4/IPv6 networks, says, "Dual-stack networks just work and are totally transparent to the end user. Anything that is IPv6 goes over the IPv6 network; everything else goes IPv4. Turn it on and no one sees a difference." Since dual-stack is so seamless, InteropNet wanted to set up additional networks that attendees can use to see what happens with network translation and in a pure IPv6 world.

The other two IPv6 demonstration networks will be WLANs in an area designated for hands-on experimentation. One will be an IPv6 network with NAT64 to perform translation between IPv6 hosts and IPv4 networks. This will give you a taste for what it will be like to transition to IPv6. The other network in the same area will be IPv6 without NAT64--so a pure IPv6 network. On this network, you will be able to see some of the problems that hosts will have. For example, Microsoft Windows XP supports IPv6, but can only make queries via IPv4. If you have Windows XP computers in an IPv6-only network, they won't be able to resolve DNS addresses. You're going to have to pry your fingers off your Windows XP systems if you haven't already.

Talking with Liebrand and Van de Velde, it's not surprising when they say getting IPv6 running isn't hard if you understand IPv6 and have a plan to follow. The latter is the critical part--having a plan. I bet in a number of ways, IPv6 networking is going to be easier than you think. Getting up to speed on IPv6 and laying out migration plans is going to be a big focus area for Network Computing in the coming years. You can bet I will be checking out InteropNet's IPv6 features with whatever gear I can get my hands on. Hope you will, too.

In this Network Computing Pro Best Practices: IPv6 Transition [subscription required], we'll discuss strategies and provide an in-depth look at three real-world deployment models.