How domain names work on the net
- By Shawn McCarthy
- Nov 13, 1995
In the Internet's Domain Name Service, each named group is
called a domain, and strings of domains are separated by periods. The largest domain
appears at the end: .gov represents the entire government domain, .mil
the entire military.
GCN's address, gcn.com, has a .com extension to indicate a commercial
organization. Some GCN machines have their own names, such as igor.gcn.com.
A machine with such a name also has an assigned Internet Protocol number that is its
true address, though almost no one uses such numbers to make connections. Instead, the
Net's domain name servers ensure that all connected machines know which numbers go with
When the IP address is known, data packets can be addressed and sent by the connected
machines' TCP/IP software.
The National Science Foundation sponsors InterNIC, a network information center that
coordinates the domain name assignments. Network Solutions Inc. of Herndon, Va.,
contracted to run the InterNIC Registration Service. Government addresses are registered
as part of the InterNIC contract; commercial users pay $50 per year for the service.
"As we process applications, we update a 'whois' database every night," said
David Graves, InterNIC business manager at Network Solutions. Three nights each week, the
Internet's 11 root domain name servers are updated.
Mark Kosters, InterNIC's principal investigator, said he's seen DNS traffic occupy as
much as 70 percent of a T1 backbone line. A 100-MHz Pentium server at NS.internic.net
handles 150 to 160 queries per second, he said, and 5 percent to 10 percent of InterNIC's
e-mail "is messages bounced by service providers that incorrectly configured their
What lies in the future for domain lookup? Probably "a classless schema,"
said NASA network engineer Marcel Schlapfer. "That's what everyone's talking about
Shawn McCarthy, a former writer for GCN, is senior analyst and program manager for government IT opportunities at IDC.