Bob2002
ULTIMATE Member
The global pool of IPv4 addresses is scheduled to run dry in 2011. Don't count on being able to get new addresses after that, and be ready for peer-to-peer applications to be hit by hard times.
We've known we would run out of IPv4 addresses since 1981, when the Internet Protocol was standardized. The numbers dictate that there will never be more than 4,294,967,296 different IPv4 addresses. (4 billion and change being the number of combinations that can be made with IPv4's 32 address bits). Before 1993, addresses were given out in very large blocks because of technical limitations in routing protocols. This limitation was lifted, but around the same time, the Internet started to become more mainstream, requiring more and more addresses.
...
Either by choice or otherwise, the big ISPs will soon have to stop giving each customer an IPv4 address of his or her own. Giving those customers just IPv6 is not an option, as the majority of the services are still IPv4-only and many IP-capable devices that don't run a full operating system (smartphones, VoIP phones, webcams) don't support IPv6. So that means stretching the existing IPv4 addresses in some way through "carrier grade NAT" (CGN).
But won't existing IPv4 users be sitting pretty? Maybe, maybe not. Some ISPs may take away addresses from existing users to provide their CGNs with enough addresses. Client-server applications such as the Web and e-mail will work just fine through CGNs and IPv6-to-IPv4 translators, but peer-to-peer applications such as VoIP and BitTorrent, not so much. Maybe the ISPs will care about that, maybe not. Even those of us who still have unencumbered IPv4 addresses at that point will start feeling the pain, as more and more of the peers we want to talk to are sitting behind largely impenetrable CGNs.
So enjoy your peer-to-peer applications while you can; their expiration date will be coming up not long after 2010.
http://arstechnica.com/web/news/2009/09/2010-could-be-the-last-year-for-ipv4-as-we-know-it.ars
It's worth clicking on the link for the longer full article (with diagrams). I actually have an IPv4 exhaustion counter widget on my Mac desktop (they have them for other platforms too). :hrmph:























