Cobalt Digital Inc RaQ 4 User Manual page 210

Appendix D: Domain Name System
To determine which primary name server contains your domain name:
1. The local name server (the DNS resolver/browser machine) contacts the
root-level name server maintained by several Internet root server authorities.
2. The root-level name server returns the IP address of the primary name server
responsible for the requested domain name.
3. The local name server contacts the primary name server.
4. The primary name server holds the IP address information for the domain
name in a database and satisfies the request from the local name server.
5. If the primary name server is unavailable, the local name server contacts the
secondary name server that satisfies the request from the local name server.
The local name server returns to the Web browser with the IP address for the
requested domain name.
6. Using the IP address, the Web browser contacts the company Web server.
7. The company Web server sends the Web page to the local name server.
Figure 67. Basic method of DNS
Local
name server
6
7
Target
machine
(www.xyz.com)
196
1
3
Cobalt RaQ 4 User Manual
4
Primary
name server
2
Root-level
InterNIC
name server
5
Secondary
name server