As useful as they are, NIS and WINS still suffer from flaws that make them unsuitable for “entire-Internet” uses.
Even though these schemes allow for multiple servers, each server must have a complete copy of the entire network topology. This topology must be duplicated to every other server, a time-consuming process if the universe becomes sufficiently large. WINS also suffers because of its dynamic registration model. A sufficient number of WINS clients could melt down any set of Internet-wide WINS servers with registration requests.
We’ve been talking about strictly technical issues up until now, but that’s not the only side of administration. NIS, in particular, requires a single point of administration. Whomever controls the master server controls the entire NIS domain lead by that machine. Any changes to the network namespace must pass through that administrative gatekeeper. This doesn’t work for a namespace the size of the Internet.
A new model called Domain Name Service (DNS) was invented to deal with the flaws inherent in maintaining host files or NIS/NIS+/WINS-like systems. Under DNS, the network namespace is partitioned into a set of somewhat arbitrary “top-level domains.” Each top-level domain can then be subdivided into smaller domains, each of those partitioned, and so on. At each dividing point it is possible to designate a different party to retain authoritative control over that portion of the namespace. This ...