Windows DNS settings for Apple Cache Server

I have recently deployed an Apple Mac Mini as a caching server but it is not downloading any apps. Can anyone tell me what the DNS settings for a Windows DNS server should be?

Which version of Apple server are you running? you should not need to configure DNS (unless you are deploying multiple servers within the same network)

Also a note Apple have made some significant changes with caching server in macOS server 5.4 and macOS High Sierra (10.13)

Caching
In macOS High Sierra and macOS Server 5.4, the Caching service moves out of macOS Server and into System Preferences > Sharing > Content Caching. The new Content Caching service supports tethered clients and a tiered architecture. Option-click the Options button in System Preferences > Sharing > Content Caching to see the advanced configurations.

Have a look at Setup The Caching Service On macOS High Sierra - krypted for setting up caching service on macOS 10./13

and macOS User Guide - Apple Support (NZ) for configuration reference

Thank you! I am currently on macOS 10.12.6 but I am going to upgrade to macOS High Sierra and then I will look at the links provided and hopefully get it working.

I will post my progress.