Why Is IPv6 Needed?

Implementing a replacement for Internet Protocol version 4 (IPv4) is a huge, expensive project. Everyone involved (other than vendors of the new products needed) would rather make do with the existing technology unless the benefits of IPv6 are so compelling that they offset the natural reluctance to undergo the risks and costs of replacement.

Migrating to IPv6 will offer three major classes of benefits: much larger address space, enabling each network-connected device to have its own IP address and eliminating the hassles of network address translation; better support for distinguishing packets (such as Voice-over-IP data, or VoIP) that require preferential treatment, leading to improved quality of service; and the ability to uniquely identify a device as it moves among networks, improving support for mobile devices.

Vast Address Space

The number of available globally unique IPv4 addresses is inadequate for even the current number of network devices, making impossible the original design goal of having unique global addresses for each device that connects to the public Internet.