Domain Name System (DNS) Configuration, Management and Troubleshooting


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Table of Contents

Domain Name System (DNS) Configuration, Management and Troubleshooting

DNS Roadmap

DNS Reference book

DNS Introduction and Overview

The situation...

In the beginning...

Domain Name System

DNS is a distributed database

Advantages of DNS

What DNS Doesnít Do

Fully-Qualified Domain Names (FQDN)

DNS Structure


Tasks of DNS Client (Resolver)

Tasks of the DNS server...

If partial answer is known...

Check our cache for answer

ěReverseî lookups

Types of DNS Nameservers

Types of Nameservers

Root Nameservers



Sample Zone file

Really ugly sample in zone file

Delegation lists all authoritative servers for a domain

Authoritative Answer

Primary Nameserver

Primary Nameserver

Secondary Nameserver

Zone Transfer

Secondary Asks for SOA

Secondary Performs Zone Transfer

Secondary Nameserver Configuration file

Secondary Nameserver SOA Magic Numbers

Caching-only Nameserver

Caching-only Nameserver



Configuration file CACHE line

Configuration file PRIMARY 127/8 line

DNS Resource Records

Resource Records

Multiple Resource Records

A Record

PTR Record

MX Record

CNAME Record

NS Record lists nameservers for the zone

Common Mistake #1: Parent and Child donít agree

Common Mistake #1: Part 2 of 2

Common Mistake #2: NS Records != Servers

Common Mistake #2 (part 2 of 2)

SOA Record

Example SOA Record

SOA Record Fields

More SOA Record Fields

Records you donít care about very much

DNS Hints

Location of Nameservers

DNS Technology: A litmus test for your ISP


Short Cuts

Record Short Cuts

Short Cuts

Pseudo-root Nameserver

Registering Domains and Nameservers

DNS Troubleshooting

DNS Troubleshooting Using NSLOOKUP


Query types



Common Problems

Problem Symptoms

DNS Configuration, Management and Troubleshooting

Author: jms


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