I am looking to create a root domain on Windows Server that will resolve internal IPs for only selected services hosted within our firewall, and forward all unresolved hostname requests to an external name server.
For example, if someone tries to access an ERP system at
https://erp.contoso.com the internal DNS will be provide LAN users with a local IP, while external users will be provided with a public IP address from an external DNS provider.
However, regardless of whether the users is on the LAN or not, all requests to
https://firewall.contoso.com for example, will be resolved by the external DNS.
How does one accomplish this? My apologies if this explanation is difficult to follow, I hope this makes sense.