i have set up an os x caching server which is doing his Job poorly. We have many iPads in our environment. I use the configurator 2 to wipe the iPads and for the enrollment process. These steps working fine for me. After i enrolled the iPads on our MDM (Casper), the Profiles get installed and the apps are installed on the iPads... but on every single process, i have 1 or 2 iPads, who are getting the apps over the Internet from the akamai servers. All other iPads installed over the caching server. We have only a 25Mbit connection to the internet. All iPads are on the same WLAN. So what is going wrong? I have no idea, why some random iPads are ignoring the caching server and other use the caching server. I enrolled 10 - 20 iPads on the same time over the configurator 2. DNS DHCP are working. The caching server are located in an extra vlan, but also failes, if we put the server on the same vlan as the iPads.
The devices will be told to use the caching server if they are contacting Apple from the same public IP address as the caching server.
The only thing I can think that would interfere with that is if you have proxies, web filters and/or load balancers in between the devices and Apple.
Ran into something similar with our network guy awhile back. It was worth having a conversation with our Apple engineer rep. who walked through our network environment and recommended adjustments (which I can't recall).
Maybe you can do the same?
I am having a similar scenario.
I was told by Apple that it is a know issue and they are working on it. The problem is related to iOS 10 upgrade and VPP Apps.
My server is not caching, all apps are being installed from the internet as the caching service is ignored.