Here's a way to get around DEP that doesn't require blocking network hosts

## these commands MUST be from Terminal in Recovery mode only (as root of course)
## this assumes the boot drive is named "Macintosh HD" and is a newer OS that has a Data volume
## you may need to open Disk Utility to mount the Data volume then open Terminal

#clear the nvram if there is any saved WiFi info there
nvram -c

#remove the known networks plist which auto-joins your WiFi - older version of macOS may not have this
rm /Volumes/Macintosh\ HD\ -\ Data/Library/Preferences/com.apple.wifi.known-networks.plist 

#the WiFi password IS still stored here but it is not necessary to remove this
rm /Library/Keychains/System.keychain

#SUPPRESS FOR SETUP ASSISTANT ONLY
#remove all the dot files .* in Settings the main file is .cloudConfigHasActivationRecord
rm /Volumes/Macintosh\ HD\ -\ Data/private/var/db/ConfigurationProfiles/Settings/.*
#When you reboot with this method you must choose Other for network options then "This Mac does not connect to the Internet" to skip Remote Management
#this method of skipping via Other/No Internet is usually sufficient for macOS 10.14 and under

#SUPPRESS PERMANENTLY
#remove the entire folder and it NEVER asks for DEP again, without this folder it won't work
rm -r /Volumes/Macintosh\ HD\ -\ Data/private/var/db/ConfigurationProfiles/Settings

reboot