BRIEF INTRODUCTION TO DNS(DOMAIN NAME SYSTEM)

Objectives

Basic Introduction to DNS Purpose of Domain Naming DNS Features: Global Distribution Fully Qualified Domain Name DNS Lookup Types

Introduction to DNS (Domain Name System) Provides resolution of names to IP

addresses and resolution of IP addresses to names

Domain Name Service/Domain Name System

74.53.142.83www.islington.edu.np

Purpose of Domain Naming Addresses are used to locate objects

Names are easier to remember than numbers

You would like to get to the address or other objects using a name

DNS provides a mapping from names to resources of several types

DNS Features: Global Distribution

Data is maintained locally, but retrievable globallyNo single computer has all DNS data

DNS lookups can be performed by any device

Remote DNS data is locally cachable to improve performance

Fully Qualified Domain Name (FQDN) Identifies a host’s name within the DNS

namespace hierarchy Host name plus DNS domain name =

FQDNHost nameHost name DNS domain nameDNS domain name

DNS Lookup Types

Lookup Types

Forward Lookup Requests name-to-address resolution

Reverse Lookup Requests address-to-name resolution

IP address for islington.edu.np?

IP address = 74.53.142.83

DNS ServerDNS Server

DNS Zone Types: Forward and Reverse Lookup

Reverse LookupReverse Lookup

DNS ServerDNS Server

Name for 74.53.142.83?

Name = islington.edu.np

Forward LookupForward Lookup

Conclusion

Thank You