The Internet is running out of network addresses, which will force the switch from IPv4 to IPv6. But IPv6 has other advantages as well, such as improving network performance and making network administrators more productive (and cheerful).
It isn’t a pretty thought to consider migrating an enterprise to a new Internet addressing scheme. Any change to the network can be time consuming and expensive to deploy. But in addition to the technical forces making the move a necessity there are good technical reasons for making the switch.
What are the differences between IPv6 and IPv4? Well, for starters, there’s a gigantic difference between the 4.3 billion unique addresses you get with IPv4′s 32-bit addressing, and IPv6′s 128 bits worth of address: 340,282,366,920,938,463,463,374,607,431,768,211,456. That’s 2 to the 128th power. IPv6 addresses are composed of eight groups of four hexadecimal numbers. So, for example, 2010:0625:0000:0000:0000:0000:0433:56cf would be a legal, albeit eye-watering address.
With that many addresses, we won’t need to worry about running out of network addresses unless we give cats and dogs Internet-enabled devices.
Fortunately, network administrators seldom need to deal with IPv6 addresses. One of IPv6′s design goals was to cut down on the time technicians had to spend configuring and managing systems. IPv6 networks can use stateless auto-configuration to assign addresses without manual intervention.
Of course, you can use Dynamic Host Configuration Protocol (DHCP) to do that on business LANs today. But, with DHCP you can only assign unique addresses within your own network.
Problems get in the way when you try to use Internet applications like videoconferencing or Voice over Internet Protocol (VoIP) with the Network Address Translation (NAT) wall that usually comes between users and the Internet with DHCP. While these problems can be overcome, they take time to repair.
With IPv6, every device on every network has a unique IP address, and your IT staff should have less trouble deploying Internet-dependent applications.
In stateless IPv6 addressing, your network equipment assigns unique IP address by combining its LAN Media Access Control (MAC) address with a prefix provided by the network router. This means your network administrators don’t need to worry about setting up unique IP addresses. Your hardware will do it for you.
Another IPv6 plus over IPv4 is that Internet Protocol security (IPSec) is built-in. IPsec is a framework of open standards for protecting communications over TCP/IP networks. Typically, it’s used in virtual private networks (VPNs) through the use of cryptographic security services. IPsec supports network-level peer authentication, data origin authentication, data integrity, and encryption. The net result should be to make all Internet traffic safer, since IPv6 can secure and authenticate communications at the network layer, instead of the higher levels of the stack such as today’s commonly used Secure Sockets Layer (SSL) and Hypertext Transfer Protocol Secure (HTTPS).
In addition, while IPv6 doesn’t prevent spam getting through completely, it becomes one more barrier for the spammers. With malware trying to get into your Windows PCs every hour of every day via e-mail, anything that helps blocks spam is a good thing.
IPv6 also speeds up networks. The header of an IPv6 packet has a fixed length, little-used IPv4 fields have been removed, and the network packet itself has been designed not to fragment. The net result is that IPv6 switches and routers throw and catch IPv6 network traffic at far higher speeds. In practice, this means that, for example, your IPv6 10Gigabit Ethernet switch should be able to send and receive traffic at 99% of the device’s top speed. Thanks to IPv4′s overhead, it can’t come as close as IPv6 does to reaching a device’s theoretical wire-speed.
That speed increase is boosted by another specific kind of performance boost that we’re all going to need more of in the coming years: multimedia performance. While you may not want your employees watching the World Cup during business hours (GOALLLL!!!), you probably do want to maximize your videoconferencing capabilities and make your real-time applications as close to real-time as they can be.
For this, IPv6 comes with baked-in support for multicast — the transmission of a single datagram to multiple receivers. Or, as Internet architect Dave Clark described it: “You put packets in at one end, and the network conspires to deliver them to anyone who asks.”
IPv4 has some multicast capabilities, but these are optional and not universally supported. With IPv6, multicast is part of the package.
While IPv6 has advantages, switching may be painful. It would be great if IPv6 were simply backwards compatible with IPv4 so we could easily switch over to the inevitable IPv6-dominated Internet. Alas, it’s not.
“The lack of real backwards compatibility for IPv4 was the single critical failure [of IPv6],” said Leslie Daigle, Chief Internet Technology Officer for the Internet Society, said at a June 2009 meeting of Internet Engineering Task Force (IETF) leaders. “The reality is that nobody wants to go to IPv6 unless they think their friends are doing it, too.”
It’s a different story today. The need to migrate to IPv6 has become more urgent, with the Internet running out of IPv4 addresses, as measured by the IPv4 clock.
The original transition plan was dual-stack. “We would start by adding IPv6 to the hosts and then gradually over time we would disable IPv4 and everything would go smoothly,” said IETF Chair Russ Housley. “It hasn’t worked out that way, although dual IPv4/IPv6 stacks will end up being part of the answer.”
There are some advantages, besides simple necessity, to switching to IPv6. Would they be enough by themselves? No, the record is clear: They haven’t been. Still, as we’re forced by the coming scarcity of Internet addresses to move to IPv6, it’s nice to know there are some advantages to be gained from our future network architectures.
Related Information From Dell.com: Create a Network Roadmap.
