First, let's get the basics out of the way. What are the differences between IPv6 and IPv4? IPv4, with its 32-bit addressing, has all of the 4.3 billion unique addresses. That sounds like a lot until you start considering that you might have an iPad in your brief-case, a computer in front of you, and a PC in front of you, all of which may have a unique Internet Protocol (IP) address. With IPv6's 128 bits worth of possible addresses, that's 2 to the 128th power, until our dogs and cats are also carrying around a baker's dozen of Internet connected devices, we should be safe from running out of IPv6 addresses.
IPv6 addresses are made up of eight groups of four hexadecimal numbers. So, for example, 2010:1003:0000:0000:0000:0000:0433:56cf would be a legal, albeit eye-watering address. Luckily for network administrators, they'll seldom, if ever, need to manually assign IPv6 addresses.
One of IPv6's design goals was to cut down on the time technicians had to spend configuring and managing network devices. IPv6 networks can use stateless auto-configuration to assign addresses without manual intervention. In stateless IPv6 addressing, your network equipment automatically assigns unique IP addresses. In short, you'll no longer need to worry about setting up IP addresses. Your hardware will do it for you.
Of course, you can use Dynamic Host Configuration Protocol (DHCP) to do that on IPv4-based business LANs today. But, with DHCP you can only assign unique addresses within your own network. DHCP and NAT (Network Address Translation) gets in the way when you try to use Internet applications like videoconferencing, Voice over Internet Protocol (VoIP), Peer-to-Peer (P2P) applications, and the like. As a user you usually don't see these problems, unless your application fails. But trust me, anyone who programs for the Internet loathes having to jump through hoops to get their applications to work through NAT. With IPv6, though, every device on every network has a unique, universal Internet IP address, and both developers and network administrators will no longer have to waste time getting network applications to work around NAT.
Another advantage of IPv6 addressing is that when you're moving from place to place with your mobile device, you'll no longer need to worry with getting a new Internet address at every stop. With Mobile IPv6, whether your smartphone or table is connected to the Internet with Wi-Fi or WiMAX, your device should retain the same address. If the wireless infrastructure around you is up to snuff, mobile IPv6 will let you seamlessly move from one form of wireless connectivity to another without losing your connection or needing to pick up a new IP address.
Another IPv6 plus is that Internet Protocol security (IPSec) is baked-in. IPSec is a popular 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 also 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 Secure Sockets Layer (SSL) and Hypertext Transfer Protocol Secure (HTTPS).
IPv6 should also speed up networks. The header of an IPv6 packet has a fixed length; little-used IPv4 fields -- Header Length (IHL), Identification, Flags, Fragment Offset, Header Checksum, and Padding -- have been tossed out; 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 higher speeds than their IPv4 brothers. 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 wire speed.
That speed increase is boosted by another specific kind of performance boost for real-time video and communications. IPv6 comes with built-in support for multicast--the transmission of a single datagram to multiple receivers. Or, as Internet architect Dave Clark described multicast: "You put packets in at one end, and the network conspires to deliver them to anyone who asks for them."
Yes, IPv4 has some multicast capabilities, but these are optional and not universally supported. With IPv6, multicast is part of the package. This will make transmitting video over the Internet, which is becoming ever more popular, a lot easier for video content providers.
So, is this going to be enough to make CIO, CTOs, and networking administrators eager to switch to IPv6? Nah! It will still cost a lot of money and take a lot of time. On the other hand, there really are some advantages to switching to IPv6 besides just being able to deal with a world that no longer has freely available IPv4 addresses. In particular, as we keep moving to an ever more mobile work world with video playing a larger role, I expect we'll learn to appreciate IPv6's faster speeds and built-in support for users on the go.