Some of you may remember dire predictions, years ago, that the Internet would soon run out of IP addresses. These predictions turned out to be somewhat early. A variety of factors combined to decrease the rate at which new address blocks were required. Still, it was clear that the limit would be reached, so the Internet Engineering Task Force (IETF) got to work designing a new IP address scheme. The new scheme is called IPv6, and supports a virtually unlimited number of addresses. The current IPv4 address system supports up to 4,294,967,296 unique addresses.
A typical IPv4 address: 126.96.36.199
A typical IPv6 address: 2001:db8:85a3::8a2e:370:7334
Before you start to panic, you should know that reaching this limit only really affects Internet Service Providers (ISPs). These organizations are the ones who buy IP blocks, then provide them to regular users. New ISPs, and ISPs that need to expand, are going to find it increasingly difficult to obtain the addresses they need.
There’s more good news: since we’ve seen this problem coming for a while now, most network hardware and operating systems are fully compatible with IPv6, including Windows XP and newer. When it’s time to make the switch, it will happen gradually, and will involve enabling IPv6 on devices and in operating systems where it’s currently disabled. Of course, there are likely to be glitches during the transition, but given the amount of testing already done, these should be resolved quickly. In most countries, the transition to IPv6 has already begun, with adoption as high as 35% in Belgium.