To communicate with a Wi-Fi network, a device must identify itself to the network using a unique network address called a media access control (MAC) address. If the device always uses the same Wi-Fi MAC address, network operators and other network observers can more easily relate that address to the device’s network activity and location over time. This allows a kind of user tracking or profiling, and it applies to all devices on all Wi-Fi networks.
To reduce this privacy risk, iOS 14, iPadOS 14, and watchOS 7 include a feature that periodically changes the MAC address your device uses with each Wi-Fi network. This randomized MAC address is your device’s private Wi-Fi address for that network—until the next time it joins with a different address.
It is not super common to find a support document about upcoming software releases, let alone documents that include a link to the public beta website, but the contents of this article are really interesting beyond that.
Device privacy is obviously huge to Apple, but there are a lot of network registration systems that use a device’s MAC address to grant access or to tie a device to an account holder. While not necessarily the best practice, it remains a common enough practice that network and managed device admins will have to deal with this coming this fall.