In order to accommodate cell phones that need to access e-mail from outside the office (through port forward on the router using mail.mycompany.com) as well as internally, when connected via company WiFi in the office, I have configured an internal forward lookup zone for mycompany.com and added the A record for mail.mycompany.com using the internal IP address of my Exchange server. Our internal AD domain is mycompany.local. Our public domain mycompany.com is hosted offsite by a web hosting provider.
But now I find that I must replicate all other A records from the public side to my internal lookup zone, or LAN clients can no longer find them, since the LAN clients see the internal zone as the sole source of DNS information for mycompany.com. For example, we have subdomains for each gateway at this client's remote locations.
Is there a way to have the internal lookup zone be responsible only for the one record that actually required me to create the internal forward lookup zone and look to the public domain by default for everything else?
I see the option to configure the internal zone as a secondary, but I have not tried that yet, so I cannot tell whether this will allow me to refer to the public-side domain as its primary and (the main point) whether it will allow me to override--for LAN clients--the one specific entry that requires a LAN IP address.