Been using DEP for a few months now but I cant use it on our network (null) without tricking it. If I was to try and image a Mac using DEP off of our network it works fine. But while on the corporate network I have to join the guest Wifi (non-production) then it will see our DEP instance then I would have to plug it into the network to begin the process.
Is there a ports or firwalls I should ask networking to look for and open so we can use DEP without tricking the machine?
If your firewall is blocking Apple's Push Notification, you can use this from Apple to get the right ports/IP's whitelisted.
If you are using JAMF Cloud then there are others you will need too.
Hope this helps.