But some company don't support that.(icloud sync)

Apple came under fire for back-pedaling on its support for IPv6, the next-generation Internet Protocol, at a gathering of experts held in Denver this week.

Comcast, for example, is urging its subscribers that are interested in using IPv6 not to upgrade to AirPort Utility Version 6.0 if they use the OS X Lion operating system, because of incompatibilities with IPv6.

Indeed, Comcast is giving only a conditional recommendation for Apple’s AirPort Utility to be used along with its new home networking service for IPv6. In contrast, Comcast offers a blanket recommendation for various IPv6-enabled home gateway models from D-Link, Cisco, and Netgear.

Comcast is the first U.S. ISP to offer an IPv6 service for home gateway users, which will be officially announced later this month. Currently, Comcast is offering this service in two U.S. cities. The service allows Comcast residential subscribers with IPv6-enabled home gateways to have native IPv6 support on any device connected to the Internet.(best dvd ripper)

IPv6 is needed because IPv4 is running out of addresses to connect new users and new devices to the Internet. IPv6 solves this problem with a vastly expanded address space, but it is not backwards-compatible with IPv4. So ISPs like Comcast have to upgrade their routing, edge, security, network management and customer premises equipment to support IPv6. The alternative is for carriers to translate between IPv4 and IPv6 addresses, which adds latency and cost to network operations.

I don't have a apple stuff, seems lucky.If someday ipv4 change to ipv6, you can't surf the web.