Serving Up DNS (The Domain Name System)
In This Chapter
Getting to know the pieces of DNS
Going back to client/server with DNS
Understanding the different DNS servers
Tracing a browser request through the DNS process
Seeing how Dynamic DNS (DYNDNS) works with DHCP
Previewing DNSSEC, a new international security initiative
DNS (the Domain Name System) is a distributed system — it’s stored in pieces across the network; no single computer holds all the information. The core of DNS is the database that stores information about domain names and addresses. Think of the DNS database as a kind of Internet telephone directory. Instead of looking up a name and finding a telephone number, you look up a computer’s name in the DNS database and find its IP address (or look up an IP address and find its name).
The heart of the Internet consists of DNS cooperating with the BGP-4 protocol (see Chapter 8) so that messages travel from source computers to their destinations. DNS lives a triple life, in the form of these three elements:
On the Internet, if DNS knows an IP address, the BGP-4 protocol figures out how to get the message there. Without collaboration between DNS and BGP-4, the Internet wouldn’t work.
Lots of pieces collaborate for DNS: hardware, software (programs and TCP/IP protocols), data files, and people. Working together, these components provide the ability to take a computer’s FQDN (fully qualified domain name) and look up its IP address or ...