Apple in an announcement Wednesday reminded developers of an upcoming change to App Store policy that requires all iOS apps include support for IPv6-only networking.
Come June 1, all submissions to Apple's App Store must be compatible with IPv6-only standards, the latest internet protocol version for hardware identification and network routing. The company first announced iOS 9 would be transitioning to IPv6-nly network services at last year's Worldwide Developers Conference.
According to an announcement on Apple's developer website, many existing apps are already compatible as the protocol is supported by NSURLSession and CFNetwork APIs. Developers using IPv4 APIs or hard-coded IP addresses will need to modify their app code to comply with Apple's new policy.
For Apple, the switch to IPv6 comes amidst wider industry acceptance of the protocol, especially from cellular carriers running networks on which iPhone and iPad operate. The proliferation of internet-connected devices, accelerated with the introduction of smartphones, is quickly depleting IPv4 address allotments. IPv6 is a successor technology and is expected to replace IPv4 in the near future.
Apple offers a set of tools for testing IPv6 network compliance as part of its developer program. In its post on Wednesday, the company pointed developers to a technical paper detailing methods of building in support for IPv6 DNS64/NAT64 networks, and linked to a WWDC 2015 session