Hi,
We are working on an app that communicates over a UDP connection on the local network. In our testing, we have a Python UDP client running on the same network, which responds when we send a message to a broadcast IP (255.255.255.255). This setup works as expected on an iOS 15 device.
However, when we test the same scenario on an iOS 18 device, the UDP communication doesn't seem to reach the Python UDP client. We've verified that the UDP client and the iOS device are on the same network, and the Python client is responding correctly.
Has Apple introduced any restrictions or changes regarding UDP broadcast behavior in iOS 18? Is broadcasting to 255.255.255.255 still supported, or has this functionality been limited in recent iOS versions?
I recommend that you have a read of Extra-ordinary Networking, and specifically the Don’t Try to Get the Device’s IP Address and Broadcasts and Multicasts, Hints and Tips posts that it links to.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
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