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Weaving a Secure Web Around Education: A Guide to Technology Standards and Security
  Table of Contents and Introductory Material
Chapter 1
  The Role of the World Wide Web in Schools and Education Agencies
Chapter 2
    Web Publishing Guidelines
Chapter 3
    Web-Related Legal Issues and Policies
Chapter 4
    Internal and External Resources for Web Development
Chapter 5
    Procuring Resources
Chapter 6
    Maintaining a Secure Environment
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Ghedam Bairu

(202) 502-7304

Appendix D: Internet Addresses and Domains

Everyone who has watched television, listened to the radio, or surfed the web in the last half-dozen years is familiar with Internet addresses or, more precisely, Uniform Resource Locators (URLs). In fact, these addresses have become so commonplace that many companies now include them, often in place of telephone numbers, as the primary contact information in their advertisements.

An Internet address is actually the verbal translation, or domain name, of a numeric Internet Protocol (IP) address, which represents a unique computer location on the Internet. For example, when the domain name is keyed into a web browser, the browser asks a server for the actual IP address (in this case,, which tells the browser how to get to the site. Users generally are not even aware that these numbers exist and, for almost all operations, use the shorthand Internet address rather than the numeric IP address.

An Internet address is broken into several different segments separated by periods. The address segments are read in backwards order to determine the location of the server. The first component of an Internet address is the top-level domain (TLD), which identifies the nature of the address owner's business. The TLD most people are familiar with is .com ("dot com"), short for commercial. In addition to .com, there are several other generic TLDs, including .org, .edu, and .net, as well as country-specific TLDs such as .us and .uk. The rules for using a particular TLD vary; for example, virtually anyone can get a .com address, but, for the most part, .edu addresses are available only to institutions of higher education.

The following table identifies a few of the TLDs that are currently available. New domains are being added constantly.

Top-Level Domains

.com None - Anyone can register. Originally restricted to for-profit companies.
.net None - Anyone can register. Originally for network infrastructure Companies only.
.org None - Anyone can register. Originally for nonprofits only.
.edu Limited to institutions of higher education (except for grand-fathered institutions).
.gov United States federal and state governments only.
.jp Japan's country code. Limited to organizations, institutions, and individuals in Japan.
.name None - Available to anyone who wants to register a name domain (e.g., john_smith).
.mil United States military only.
.kids For noncommercial children's content. Not yet available.
.biz None - Anyone can register.
.info None - Anyone can register.
.us None - Anyone can register. The .us domain is the United States country code. Originally limited to a geographic system of naming ( ), but being reformed.
.tv Tuvalu's country code (an island nation in the South Pacific). No restrictions. Widely used for television-related industry.

The second-level domain (SLD) is the portion of the URL that identifies the owner of the IP address. The rules for SLDs are even less regulated than those for TLDs. Some TLDs, such as .com, have no restrictions at the second level, so virtually anything can be registered. Others have significant SLD restrictions, such as .us, which requires state identifiers at the second level.

Starting from the TLD and working backwards, the Internet address provides information about the address owner. Using the example, it can be determined that the address owner (TLD) is

  1. .gov, meaning it is affiliated with the U.S. government;
  2., meaning it is part of the U.S. Department of Education (SLD); and
  3., the National Center for Education Statistics at the U.S. Department of Education.

Similar rules apply as more and more domains are added to an address. The drawback to increasing the levels of information within an Internet address is that the address can become unwieldy. The more levels in the address, the more difficult it is to remember. School districts have been traditionally sequestered in the .us domain, and they consequently often have web addresses that can be hard to recall from memory.

When choosing a domain name, one should exercise judgment in determining whether a short and simple or longer and more descriptive name is appropriate, and then check to see if it is available for use. Companies that sell domain names for profit quickly snatch up simple domain names. To check the availability of a domain name or to register a name, one should go to any online domain registrar, such as or The cost of registering and maintaining a domain name is approximately $35 per year.

Multiple addresses/domain names can be registered for a single web site for a variety of reasons. For example, General Electric, for access to the same site, registered both and An education agency or district can likewise register multiple addresses for its web site; however, only a single address should be advertised to minimize confusion among staff, parents, and the public. A district may choose to register different addresses in order to convert a long domain name to a shorter one or to guarantee that an alternate address will remain available for use by the district at a future date. More importantly, the registration of potentially competing or confusing addresses prevents them from being used by someone else.