Does the Aspen controller have a built in DNS server, and is it a primary or secondary?
No. DNS is a vital element of enterprise or SMB server infrastructure, and most people are using (1) an outsourced DNS service, or (2) managing their own best-of-breed DNS servers, or (3) a combination of both of these approaches, e.g. have a primary DNS server managed by an outside provider and a secondary DNS server on premises. Aspen’s smart DNS caching algorithms are designed to passively learn by observing real DNS traffic, and communicating when necessary with external DNS services the customer is using.