The not-so-new IPv6 protocol will force change upon the internet as we know it today. Humans tend to intensely dislike change, especially the unavoidable kind. That's probably the main reason why IPv6 has been languishing in the far corners of the internet for years. The new protocol does have a lot going for it, though.

My private home network has been IPv6-enabled for a year and a half now. It provides me with the means to access all of my computers from the outside world. Something that's initially impossible when using IPv4 behind a NAT router, which translates traffic from and to your internal network. The possibilities to circumvent the limitations of NAT are impractical at best, requiring you to juggle port numbers and offering services on non-standard ports because ports can not be shared.

Residential internet connections will, with the advent of IPv6, finally be released from the current choke hold the IPv4 address shortage imposes on it. It's been common practice for well over a decade for residential internet connections to receive just a single IPv4 address. Only at the very start of ADSL availability in the Netherlands did I see subscriptions offer a /29 subnet, which amounts to 6 usable addresses. Within this century I have yet to see a consumer subscription plan to offer more than a single address.

The IPv4 address shortage makes it logical for ISP's to distribute addresses as sparingly as possible. With IPv6 it's a completely different story. A standard IPv6 subnet has 2⁶⁴ addresses, the square of the entire IPv4 address space, all publically addressable and all yours. This opens up a wealth of possibilities.

Things like tech-supporting your less than computer literate friends and relatives becomes a lot simpler. You can simply setup up the firewall on their end to open up to your private subnet (and no other). Such a set-up allows you to use remote desktop tools to directly troubleshoot problems on your mom's laptop instead of guiding her unsure hand blindly by speaking instructions over the phone.

Similarly you can easily set up file sharing between the private subnets of your friends. Confidentiality of such an arrangement of course requires encryption. Something the IPv6 designers provide in the form of mandatory availability of IPSec in every networking device that implements IPv6. Being able to enter all your own home computers into the global DNS database makes this kind of communication a lot easier still.

Stuff like VOIP, BitTorrent and other peer-to-peer communications protocols also benefit greatly from direct addressability of all the nodes in the network. For example it won't require any trickery to simply hook up all your phones and microphone-equipped laptops, netbooks and tables to your internet connection and place calls across the data network no matter where you are. And then there will be applications I can't even dream of yet.

But IPv4 can do all of that!

Sure, most of the functionality described here is feasible using a single IPv4 address plus NAT. It would, however, require inordinate amounts of trickery such as dynamically updating DNS through a third party service, creating compatible number plans in advance between RFC1918 compliant private subnets that you want to connect by VPN. Not to mention much more complex firewall rules and risky dynamic updating arrangements for them that take into account changing IPv4 addresses on each public endpoint of your VPN.