We're having a debate about best practice for configuring a secondary DNS server on a one DNS server network.
On a one server (Windows / DC / DNS / DHCP / File) network, DHCP will be configured to give out the Domain Controller' s address as the Primary DNS server.
What's the best practice for configuring a secondary DNS server?
One school of thought is that for this small network with no other servers, there would be no viable second DNS server to give out so it shouldn't be configured.
Another school of thought is that an external, public DNS server should be listed. This has the advantage that clients would still be able to use the Internet if their DNS server is offline. This disadvantage is that the public DNS server would be worthless at resolving internal resources and could cause problems on a healthy network.
I've been unable to find any best practices to refer to settle this dispute.