I have always blocked iOS updates ever since 11.0 came out and slammed all my Internets.
I follow the guide from here: https://documentation.meraki.com/zGeneral_Administration/Other_Topics/Blocking_or_rate_limiting_iOS_...
However, I have noticed of late that I still see devices performing updates, but it would appear that they are using a new URL to do so.
Anyone else seeing this?
I don't have the ability to test this myself to confirm if we now need to add this 3rd URL to the above 2 mentioned in the article.
That certainly looks like a valid URL since it's going to aaplimg.com. I do suspect that blocking it would break other Apple services however.
I have previously used a L7 firewall rule on guest WiFi. I haven't tested it recently to see it it still blocks the Apple updates, but it certainly used to.
Bear in mind that software updates come via the Mac App store, turning this off would also affect the machine being able to access the App store. It could also affect iTunes as well.