Our OS X Server serves our company DNS, web and mail with an external IP address to the Internet.
It currently does not have a local address on the LAN and thus cannot be used e.g. for software update caches for OS X and IOS devices on the network.
If I were to also attach the server to the LAN by one of its other ports would I be compromising its security or the security of the LAN?
I am more concerned about opening up a security hole from the WAN into the LAN than vice versa as I can control which users have access to which services on the Server.
OS X Server has its adaptive firewall enabled and the router via which it connects to the WAN has only those ports open that we need for the services it serves.