Section 2 - Domain Naming

At the end of Section 1, we examined a simple Internet operation - a hypertext page transfer. Remember these key points?

• A Web browser requested this URL: http://www.FreeSoft.org/Connected/index.html

• The DNS protocol was used to convert www.FreeSoft.org into the 32-bit IP address 205.177.42.129

• The HTTP protocol was used to construct a GET /Connected/index.html message

• A table lookup in /etc/services revealed that HTTP uses TCP port 80

• The TCP protocol was used to open a connection to 205.177.42.129, port 80, and transmit the GET /Connected/index.html message

• The IP protocol was used to transmit the TCP packets to 205.177.42.129

• Some media-dependant protocols were used to actually transmit the IP packets across the physical network

Over the next few sections in this course, we'll be looking at each step of this procedure at a high level of detail.

In this section, we'll examine the DNS protocol, used in the second step to convert the hostname www.FreeSoft.org into 205.177.42.129, the 32-bit numeric address used by the TCP and IP protocols.

Now, click here to continue.