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DNS

Domain Name System / Services

Introduction of DNS:--User Friendly Name :-

1> Host Name (Computer Name)

> F!DN Name(Full Computer name includedomain name)

User identify only user friendly name and all computer andtec"nolo#y identify I$ address and %&C address'

e can use t"e DNS to sole t"is pro*lem *ecause DNS is

conert "ost name+ F!DN to I$ address and I$ addressto "ost name+ F!DN'

e can also called Name ,esolution t"is process

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Why Need of Name Resolution

./p:-- User can not remem*er lot of num*er of I$address li0e '21'33'4 *ut user easily remem*er

user friendly name li0e ya"oo+ "otmail+ #mail and

anot"er name'

5ut computer identify only I$ address

So easy to ma0e t"is tec"nolo#y *efore reac"in# user

DNS is conert I$ address to Host Name'

Note :- Net6or0 is completely 6or0 6it"out DNS *utdifficult to use'

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DNS SystemDNS is a serices t"at maps domain Name to t"eir I$ address'

DNS is a complete system and lot of computer 6or0 in t"is system $art of DNS system:-

Host Name+Domain Name+Namespace DNS Serer'

Host Name:-Host name is a computer name' "ost name is also called

Net5I7S name (Net6or0 5asic Input87utput System) 6e can identifyof t"e computer *ut 6e can not identify of t"e location of t"e

computer' If 6e use t"e I$ address t"an 6e identify net6or0 6it" t"e

"elp of Net Id'

Note:- 6e can identify of computer 6it" "ost name on small net6or0 *ut

6e can9t identify computer 6it" "ost name on lar#e net6or0 or

internet 6or0' "is is a disadanta#e of t"e internet'

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Rule of IP Address

I$ &ddress "as diided in t6o parts

Host ID:- Identify of t"e computer'

Net ID :- Identify on t"e net6or0 (Complete ;ocation)I$ address is use on internet *ecause I$ address "as t6o

part "ost id and net id' %&C address is use only for identifyof t"e "ost name (computer name) So 6e can not use%&C address on internet 6or0'

Domain Name:-Domain name is t"e identify t"e internet

site'

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Domain NamespaceDomain namespace ena*le user to easily locate t"e net6or0 serice

and resources' "e domain namespace include t"e root domain+ t"e

top leel domain and second leel domain of t"e or#aniation andor#anie t"ese domain in "ierarc"ical ree Structure'

(IC&NN) Internet Corporations &ssi#ned Name and Num*er'(Root Domain)

.net .com .org .edu .in

yahoo rediff gmail

account naukrichat

(Top evel Domain)

(Second evel Domain)

(Su! domain)

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DNS Server&ny computer proidin# domain name serice is a DNS serer' DNS

serer is conert "ost name F!DN into I$ address and I$ address

into "ost name F!DN'

Components of t"e DNS Serer :---

DNS !uery:

DNS Serer Cac"e: DNS ?one:

DNS ,esource ,ecord:

DNS !uery:- DNS is a re@uest for name resolution t"at issend to DNS serer *y t"e client in a net6or0' & client can

send @uery to a DNS serer or DNS serer can also send a

DNS @uery to anot"er DNS serer'

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DNS Query Are Two Types

1) ,ecursie DNS !uery:In t"is @uery DNS serer did not ta0e

responsi*le to find *est ans6er for client' DNS serer can for6ard

t"is @uery to ne/t anot"er DNS serer'

) Iteratie DNS !uery:Is a @uery in 6"ic" t"e client accept t"e *est

aaila*le ans6er from t"e DNS serer' In case if t"e serer doesnot 0no6 t"e ans6er + it may direct for6ard t"is @uery anot"er

DNS serer' &ll 5urdon on local DNS serer'

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DNS Server Cace:Is t"e temporary stora#e area in t"e DNSserer t"at store t"e most fre@uently or recently access records'

"is cac"e is clear 6"en DNS serice is stopped'DNS !one: one is a part of DNS data*ase t"at contain record of

domain or multiple domain' ?one also contain a list of "ost nameto I$ address mappin# for t"at domain'

ype of ?one:-

1) For6ard loo0up ?one:- It conert F!DN into I$ address'

) ,eerse ;oo0up ?one:- It conert I$ address into F!DN'

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Types of !one

Primary Zone:&ll DNS record are created in it' "is is first one in

t"e net6or0' e can addition+ t"e DNS record are created andmodified in t"e primary one'

Secondary Zone:Is t"e DNS one t"at contain a read only copy oft"e DNS record t"at are store in t"e primary one' "e record store int"e secondary one cannot *e modified' It also called *ac0up of

primary one'Stub Zone:"is is copy of t"e primary one *ut it contain only t"ose

resource records t"ose are necessary to identify t"e sereraut"oritatie for t"e master one' Stu* ?one is a one 6"ic" containst"ree important records+ t"at is+ start of aut"ority (S7&) record+ name

serer(NS) record and t"e #lue "ost (&)record of anot"er DNS serer'Active Directory Integrated Zone:"is one is created

automatically 6"en 6e install and confi#ure &ctie Directory'

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DNS Resource Record

Start of Autority "S#A$ Record:-"e first record in

any data*ase is represents t"e S7& record'Name Server "NS$ Records:-Name serer (NS)

record contain t"e domain name serer'

%ost "AorAAAA$ Resource Records:-"eserecord map t"e DNS domain name of t"e

computer (or "ost) 6it" t"eir I$ address' ./p'' If

t"e "ost name serer1'a*c'com"as t"e I$

address is 1A'13B''1'

serer1 & 1A'13B''1

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Alias "CNA&'$ Records:-"is is t"e s"ort name of t"e

F!DN li0e t"is pc1'ro61'la*1B'floor'oserices'comt"ese I$ address is '''1 t"is CN&%. is

666'oserices'com t"ese I$ '''1

&ail '(can)e "&*$ Record:-Used *y e-mail

applications to locate mail serers 6it" in one'

Pointer "PTR$ Records:- Used only to support reerseloo0up one' It conert I$ address into "ost name'

Note:- INS (indo6s Internet Namin# Serer) it conertNet5I7S into I$ address' INS is old ersion of t"e DNS

serer

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Install DNS Server Role

Step of DNS Serer installation and un installation

StartSerer %ana#er

Select ,oles

&dd ,oleC"ec0 *o/ of DNS (Domain Name System)

Serer

Some time ne/tand Finis"For un installation Eust unc"ec0 t"e DNS *o/ and o0

and finis"

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Some DNS CommandsC:>tracert 666'ya"oo'com:--Command is use to c"ec0 t"e

pat" a data pac0et follo6 from one router to anot"er router'

C:>Nsloo0up :-- Command is display t"e Domain name 6it"I$'

C:>Ipconfi# 8all :-Display t"e I$ address 6it" F!DN+ I$

address %&C address'C:>ipconfi# 8flus"dns:- Flus" and reset t"e DNS resoler

cac"e

C:>ipconfi# 8displaydns :-Display t"e contents of DNS

resoler cac"e'

C:>ipconfi# 8re#isterdns :-,e#ister any DNS names'

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