With the allocations of IPv4 prefixes 39/8 and 106/8 to the Asia Pacific Regional Internet Registry (Apnic), the internet has run out of address space. By earlier agreement, the five /8 blocks IANA has left will now be handed out one per regional internet registry (RIR). This article on ZD Net explores how things will be in the new age of IPv6, especially for those ISPs and content providers have declined to rush to deploy IPv6.
“While IPv6 is not directly interoperable with IPv4, being IP it runs under TCP/UDP and over the same link layers as IPv4. Through updates to APIs, network stacks and routing protocols, IPv6 can be run alongside IPv4 on the same infrastructure — a technique known as ‘dual-stack’. This is the most common way IPv6 is being introduced today. It means devices on your network can communicate natively to external IPv4 or IPv6 systems without any form of translation required. You can also roll out dual-stack incrementally.”