Basic Method Of Dns - Cobalt Digital Inc COBALT Qube 3 User Manual

Appendix E: 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
domain name server maintained by the several Internet root server
authorities.
2. The root domain 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 118. Basic method of DNS
Local
name server
6
7
Target
machine
(www.xyz.com)
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1
3
Cobalt Qube 3 User Manual
4
Primary
name server
2
Root-level
InterNIC
name server
5
Secondary
name server