IP - The Next GenerationNot just a Star Trek quip, the next version of the protocol, IPv6, is also known as IPNG (IP Next Generation) or Internet 2. It's the natural successor of IPv4 and stands tall where IPv4 fails.
And it's actually not a new thing.
IPv6 has been adopted by the Internet Engineering Task Force (IETF) since 1994. But what sets IPv6 apart from its predecessor anyway? The key elements are as follows:
Gigantanourmous number of addressesIn fact, it's hard to wrap your ahead around the size of the address space, but here goes: an IPv6 address is 128 bits long compared to IPv4's 32bits. This provides 2^128 possible addresses.
Can't imagine the number? It looks like this: 340,282,366,920,938,463,463,374,607,431,768,211,456. The popular example to visualise this incredibly large sequence of decimal digits goes thusly: if, for whatever reason, you wanted to divide the number of unique addresses among the surface area of planet Earth you could allocate 665,570,793,348,866,943,898,599 addresses for each square meter of the planet.
Alternatively, if you wanted to divide up this number among the world's population as it stands at the moment, each and every person would be entitled to some 56 billion billion billion (yep, three big fat billions) addresses. It doesn't matter if you were a Borg, and your pockets were filled with PDAs and webcams and various inter-dimensional trans-warp inversion-field dilithium crystalised network-capable gadgets, you simply couldn't use these if you tried.Sound like overkill? Remember, Bill thought 640k would be enough for everyone, and before that the biggest booboo of geekdom was when certin smarty pants people who thought the world was flat. So let's be honest: it is a rather big address space, but that just means we have to get out there and colonise space and make Licklider's 'galactic network' a reality.
And keep in mind that, even now, our world is becoming increasingly IP driven -- from PDAs and webcams through to fridges and mobile phones, let alone PCs. So the room to grow in IPv6 will be needed soon as IPv4's address space, even with NAT, becomes exausted.
AutoconfigurationIPv6 is designed to make configuration easier. In fact, if at least one machine on the network is configured as a router, all other IPv6 hosts can configure themselves -- and you don't need DHCP to do it. This is known as stateless autoconfiguration and works like this: when it's brought up an IPv6 interface will broadcast on the network asking to be told where it belongs. An IPv6 router can send back a router advertisment packet that contains details like the IPv6 header for the network and even information like gateway address. The IPv6 host combines the header with an address dervied from the MAC address of the physical interface and configures itself. Since MAC addresses are (or should be) unique, the interface is registered with an IPv6 address without any form of human intervention. This is all part of the protocol and different from DHCP in that there is no central process or machine keeping a record of which addresses belong to which machines.If you do want to keep and manage records, otherwise known as stateful configuration, you can use the new DHCP for IPv6, known of course as DHCPv6.Finally, IPv6 allows interfaces to be aware of nearby IPv6 machines -- called neighbour discovery, all IPv6 interfaces can learn the addresses of other machines, similar to the ARP (Address Resolution Protocol) cache in IPv4, therey speeding up and helping in the routing of packets.
Built in IPSECIPv4 is notoriously insecure. IPv6 builds in IPSEC (IP Security) as part of the protocol -- meaning authentication and privacy are an element of the protocol itself, and not tagged on at the application level. This will ease, among other things, the creation of secure VPNs (Virtual Private Networks) which will, in turn, be a catalyst for even more expansion of the net as a tool for buisness, commerce and personal use. The integration of IPSEC in this way will help prevent IP spoofing and make eavesdropping on someone else's data that much harder (though still not impossible).
PerformanceIPv6, despite using larger headers than IPv4, has less overhead than is more efficient at routing. Additionally, there's no longer a need to checksum at the network layer, and fragmentation happens at the source host rather than at routers along the destination path. What this means for the end user is faster routing, and better use of bandwidth. And remember, this doesn't just apply to the internet, but LANs as well. In fact, IPv6 can support what's known as jumbograms -- extremely large, and in fact possibly unlimited in size, data payloads for packets.
MobilityIPv6 brings inherent advantages for mobile networking -- since advanced routing is built into the design of IPv6, as well as greater support for multicast traffic, not to mention built in IPSEC, it will be easier for you to access your home or work network through mobile devices on the run anywhere in the world securely and with a minimum of fuss.There are a multitude of other differences relating to addressing scopes and routing, but the above are the biggies.
All modern operating systems today, including Windows and Linux, have full IPv6 support right down to the application level.
So why don't we have IPv6 as the standard right now? Largely due to NAT, IPv4 has some legs left in it but more importantly there are billions upon billions of dollars alredy tied up in IPv4 infrastructure. Until the lack of IPv6 actually breaks things, there's no impetus to make the transition. Even when adoption grows, which it will very slowly, we can expect it to take decades as the world moves into mixed IPv4/IPv6 networks before finally taking the trusty IPv4 protocol out the back.
Some, however, are pushing for it sooner. The US government, for example, has mandated that its military networks complete the move to IPv6 by 2008. Hopefully this will raise awareness and kickstart other industries to start making the switch.
Issue: 137 | June, 2012