Q: VPP DEP internet mandatory

We have a bunch of DEP enabled iPad's in a Facility of a customer of ours where the iPad's aren't allowed to use HTTP or HTTPS externally.

I have setup these iPad's to use VPP Device Licensing so that we won't have to create separate Apple ID's for each iPad.

We use Filewave to distribute the Apps we have bought through the VPP program, the thing is when we distribute an VPP app it only appears on the iPad after we enable HTTP/HTTPS (to internet) on our Firewall. I guess this is because of some checking within the VPP program which is logical.

The thing is we can't have the users of these iPad's browsing the internet so the question really is:

Is there any information about which DNS / IP adressess are being used for the VPP/DEP checks so that we can set some rules to allow traffic for these addresses in our firewall?