User manual

Cobalt RaQ 4 User Manual 179
Appendix D
Domain Name System
Basic DNS
The Internet uses a distributed naming system called the Domain Naming System
(DNS). DNS allows us to refer to computers by host names as well as by Internet
Protocol (IP) addresses.
IP addresses are hard to remember and are inconvenient to use. DNS allows us to
use host names and domain names which can resolved to IP addresses. DNS
servers translate host names and domain names (for example, www.cobalt.com)
to an associated IP address (for example, 192.168.1.10.)
For example, Cobalt Networks has registered the domain name “cobalt.com” for
use by our servers “mail.cobalt.com”, “www.cobalt.com” and others. The host
names “mail” and “www” represent different servers registered in the same
domain.
A domain name is a computer name suffix shared by a group of computers in the
same organization. A domain name should be associated with an IP address
through a Forward Lookup record. Domain names are organized in a hierarchy;
this hierarchy includes your company or server name, and a country code (for
example, .uk or .ca) or a top-level domain (for example, .com or .edu).
A Web site on the server is created with one IP address, one host name and one
domain name that together establish the identity of that Web site on the Internet.
Each domain name requires a primary domain authority on one DNS server. A
secondary DNS server acts as a backup to the primary. DNS information is
configurable only on the primary server, and not on the backup server.