How to stuff 4,300,000,000 networks into your datacenter

It's unlikely you've missed the coverage of the upcoming exhaustion of the current IP address space. With IPv4's 32-bit address space support for a measly 4.3 billion devices, the proliferation of IP addressable everything has made that once large seeming number feel like a collar that's a bit too tight. The rollout of IPv6, with its 128-bit address space, takes care of that restriction for the foreseeable future, but it means that there will need to be a transition between the two addressing models.

Fujitsu has announced that they have developed a technology to smooth the transition from IPv4 to IPv6 for datacenter operators; the SA46T/SA46T-AS Datacenter Solutions.  Designed to remove limitations on the number of IPv4 networks that can be virtualized over IPv6 connections the two parts of the technology do this by allowing the accommodation of approximately 4.3 billion IPv4 addresses on an IPv6 network using SA46T (Stateless Automatic IPv4 over IPv6 Tunneling) a mapping and addressing protocol for IP4 to IPv6 and SA46T-AS, which allows for the sharing of one IPv4 address among up to 64K devices.

These technologies are designed to replace the traditional VLAN model in use in most datacenters, which are limited by IPv4 as to the number of networks that can be supported. Fujitsu states that the average number of VLANs supportable by current technologies is roughly 4000.

The technology is being pitched as a migration strategy for moving from IPv4 to IPv6, and allows the datacenter operator to continue adding servers and devices to their networks with both types of IP address and is being demonstrated, starting today, at the Interop trade show in Tokyo.  Fujitsu is also proposing these technologies to the IETF as a candidate for adoption as a standardized technology.