Uptown DC will be the primary DNS server for and for a 192.168.0.x reverse-lookup zone, and it will be the secondary DNS server for a 10.0.0.x reverse-lookup zone.
Then, as today, each device on the network was a node, and each node needed a unique address to enable data packets to find their destinations.
On Windows On Mac Community Q&A This wiki How teaches you how to clear your computer's DNS cache, which is a collection of recently visited websites' addresses.
Clearing the DNS cache will usually solve "Page Not Found" errors and other DNS-related errors.
Glue records are needed to prevent circular references.
Circular references exist where the name servers for a domain can't be resolved without resolving the domain they're responsible for.