FreeBSD6 Unleashed

Hostnames and Domain Names

Now that you have an understanding of the way MAC addresses and IP addresses work, you can apply yet another layer of indirection to the host-finding process: hostnames and the Domain Name System (DNS). Hostnames assign human-readable names to machines that otherwise would only be identifiable by their IP addresses, and DNS is the mechanism by which those names are assigned.

Early in TCP/IP history, different networked machines were identifiable only by their IP addresses. This worked really well, until the number of online people grew so large that keeping track of all the numbers involved was tedious and error-prone—nobody wanted to have to keep huge lists of IP addresses and what they all referred to. Hence the ...