Understanding Networking Protocols
the address http://220.127.116.11. To solve this problem, a system called the Domain
Name System (DNS) was developed.
DNS enables people to register domain names with ICANN and then use them to
Domain names are given out on a first-come, first-served basis. However, ICANN gives
preference to a holder of a valid registered trademark if a conflict develops. ICANN, upon being
presented with valid trademark information and notice of the domain name that infringes on that
trademark, goes through a process to assess the truth of the claim and, if necessary, takes a
domain name away from its present holder and transfers the name to its rightful owner.
Domains are organized in a tree arrangement, like a directory tree on a disk drive.
The top level defines different domain types, called top-level domain names (TLDs).
The most common is the .com domain type, usually used with for-profit commercial
entities. The following are other common domain types:
.edu for educational institutions
.gov for governmental entities
.mil for military entities
.net for Internet-related entities
.org for nonprofit entities
xx for different countries, such as .it for Italy and .de for Germany (Deutschland)
In recent years, a number of other TLDs have been added to the system, such as .biz,
Within a domain name, entities are free to add other names before the beginning of
the domain name, and these usually refer to a particular host or server, or sometimes
to a particular type of service for that domain. For example, if you had the domain
bedrock.gov, you would be free to create additional names, such as quarry.bedrock.gov
As a matter of standards, the first portion of a domain name preceding the actual
domain name indicates what type of service is being connected. For instance, www
.bedrock.gov would be used for a World Wide Web server for the domain bedrock.gov
and ftp.bedrock.gov would be used for an FTP server. The standards for service types
within the domain name are usually followed, but not always. The owners of domain
names are free to invent their own service types that meet their particular needs. For
example, some domain name holders refer to their e-mail servers as smtp.domain.org;
others might prefer to use mail.domain.org.