|
DNS Name Servers and Name Resolution
The preceding two sections describe
the Domain Name System's hierarchical name space, and the authorities
that manage it and are responsible for name registration. These two
elements, the name space and name registration, are the more “intangible”
parts of the name system, which define how it is created and managed.
The “tangible” aspect of the name system is the set of software
and hardware that enables its primary “active function”: name
resolution. This is the specific task that allows a name system
to replace cumbersome numeric addresses with easy-to-use text names.
Name resolution is the part of DNS
that generally gets the most attention, because it is the portion of
the system that most people work with on a daily basis. DNS uses a very
capable client/server name resolution method that makes use of a distributed
database of name information. The most commonly used implementation
of the DNS name resolution process is, of course, the one used for the
Internet itself, which resolves many billions of name requests every
day.
In this section I explain in detail
the concepts and operation of the DNS name resolution function. The
section is broken into three subsections. The first two cover each of
the two key software elements that work together to implement the DNS
client/server name resolution function. The first describes DNS name
servers, and how they represent, manage and provide data when resolution
is invoked. The second describes DNS clients, called resolvers,
how they initiate resolution, and the steps involved in the resolution
process. After these I have a third subsection that ties together the
information about name servers and resolvers by providing a look at
message exchange between these units, and describing the formats of
messages, resource records and DNS master files.
 Related Information: A set of related TCP/IP utilities called nslookup, host and dig can be used by an administrator to query DNS name servers for information. They are useful for a variety of purposes, including manually determining the IP address of a host, checking for specific resource records maintained for a DNS name, and verifying the name resolution function. See the topic discussing these programs in the section on TCP/IP administration utilities.
|
|
Quick navigation to subsections and regular topics in this section
|
| If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support! |
|
|
Home -
Table Of Contents - Contact Us
The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005
© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.
|
Background Information: The material in this section assumes that you are already familiar with the topics in the preceding two sections, and references those sections where appropriate. If you have not already read the sections on the DNS