Prevent iOS auto-pushed update.

Apple's iOS updates can and may be auto-pushed (downloaded to your device without your knowledge) to your iDevice. Some users may want to stay at an older iOS version for many reasons, the main reason being the decreased performance of newer iOS versions on older iOS devices.

The iOS auto-pushed updates may be downloaded to your device when:

a. The device is not running the most current iOS version that it qualifies for

b. The device is connected to a Wi-Fi network with adequate throughput

c. The device has the required storage space available on it to hold the iOS update file

d. The device is powered externally via USB connection to a Mac/PC's USB ports or connected to an external USB charger

Here are some known ways to prevent the auto-pushed update from being auto-pushed to your iOS device:

1. In your Wi-Fi router's settings, set up a block (using Access Restrictions or similar in the router's web interface) to mesu.apple.com. This will prevent your device from "phoning home" to Apple, checking for the update and getting the download auto-pushed to it again (it may repeatedly get auto-pushed again to the device, even if you remove the iOS update file from the device; see #3 below). Note that your router may not have this ability to block access to certain locations. In this case, see #2 below. Also note that connecting to a Wi-Fi router other than your own (with this block in place) will expose the device to the auto-pushed update. The block will only be valid when using your own Wi-Fi network.

In the future to check for updates on the device itself, simply disable the Access Restriction block created above. After you've checked for updates, remember to reenable the Access Restriction block that you disabled.

2. Before connecting your device to your Mac/PC's USB ports or before connecting it to an external USB charger, disable Wi-Fi on the device itself under:

a. Settings/Wi-Fi, then toggle the Wi-Fi switch to the OFF position

b. Drag-Slide up on the touch screen from just above the Home button on the device to expose Control Center, then tap on the Wi-Fi symbol button(between the airplane and Bluetooth buttons) to toggle Wi-Fi off (the button will darken when in the OFF position)

3. If your device already has the auto-pushed iOS update installed on it and you do not wish to install it for whatever reason, find the iOS update app under:

Settings/General/Storage & iCloud Usage/Manage Storage. Scroll through the list of installed apps to find the iOS update app, tap on the app, then tap the red "Delete App" button.