DNS

1. PRSENTATION ON DOMAIN NAME
SYSTEM(DNS)
 PRESENTERS:
 SAROJ ARYAL
 Queries: www.fb/sarojsaroza

2. ACKNOWLEDEMENT
DURING THE DESIGN OF THIS PRESENTATION OUR GROUP
ARE VERY ENCOURAGING SOULS WHO ARE SUPPORTING
EACH OTHER IN THE GROUP. WE CANNOT STAY WITHOUT
GIVING SINCERE THANKS TO THEM.
WE ARE GREATFUL TO OUR SUBJECT TEACHER
MR.NABENDRA SHRESTHA,FOR PLAYING THE ROLE OF
GUIDENCE AND GIVING US SUCH A PRESENTATION WHICH
IS IMPOSSIBLE WITHOUT HIM.
-PRESENTERS

3. CONTENTS
DOMAIN NAME SYSTEM(DNS)
 BACKGROUND
 DNS NAME SPACE
 TYPES OF DOMAIN NAME
 RESOURCE RECORD
 DOMAIN NAME RESOLUTION
WORLD WIDE WEB(WWW)
 BACKGROUND
 ARCHITECTURAL OVERVIEW
 HOW WWW WORKS?

4. CONTENTS
E-MAIL:
 HOW TO SEND E-MAIL?
 ADDRESS
 ARCHITECTURAL OVERVIEW
UNIFORM RESOURCE LOCATER(URL):
 INTRODUCTION
 EXTENSION USED
 CONCLUSION

5. DOMAIN NAME SYSTEM
BACKGROUND:
- COMPUTER CAN WORK EASILY WITH LONG INTEGER OF IP
ADDRESS BUT HUMAN THAT HAVE PRETTY DIFFICULT TO
REMEMBER SO, MOST OF THE COMPUTERS HAVE AN ADDRESS
CALLED DOMAIN NAME WHICH MAKE READABILITY HIGH.
INTRODUCTION:
-DNS IS AN INTERNET SERVICE THAT TRNSLATES DOMAIN
NAME INTO IP ADDRESS. EG: DOMAIN
NAME:WWW.EXAMPLE.COM (198.105.232.4).
-IT IS DONE FOR COMMUNICATION PURPOSE .
-RESOLVER(LIBERARY PROCEDURE) PASS THE NAME AS
PARAMETER TO LOCAL DNS SERVER,THAN IT RETURNS THE IP
ADDRESSES TO THE RESOLVER.

6. DNS NAME SPACE
 A HIERARCHICAL NAME SPACE IN WHICH THE NAMES
ARE DEFINED IN INVERTED TREE STRUCURE WITH THE
ROOT AT THE TOP.
 IN WHICH TREE CAN HAVE INLY 128 LEVELS.
 ADRESS SPACE IS DIVIDED INTO DIFFERENT LEVEL OF
DOMAIN (TOP LEVEL DOMAIN AND SUB DOMAIN).
 INTERNET IS DIVIDED INTO OVER 200 TOP LEVEL
DOMAINS WHERE EACH DOMAIN COVERS MANY HOSTS
AND EACH DOMAIN IS PARTITIONED INTO SUB DOMAINS .
 TOP LEVEL DOMAIN COMES INTO TWO TYPES:
 GENERIC: IT REPRESENTS THE TYPE OF THE ORGANIZATION
SUCH AS COM,EDU,ORG ETC.
 COUNTRY :IT INCLUDES ONE ENTRY FOR EVERY COUNTRY SUCH
AS NP,IN,SP,UK,PK ETC.

8. TYPES OF DOMAIN NAME
 FULLY QUALIFIED DOMAIN NAME(FQDN):
 IF LABEL IS TERMINATED BY THE NULL STRING OR ROOT .
 CONTAIN FULL NAME OF HOST. EG: MAIL.YAHOO.COM
 PARTIALLY QUALIFIED DOMAIN NAME(PQDM):
 IF THE LEBEL IS NOT TERMINATED BY NULL STRING.
 DOESNOT CONTAIN FULL NAME OF HOST. EG: CS.TU

9. RESOURCE RECORDS
 RESOLVER GIVES A DOMAIN NAME TO DNS THEN WHAT IT
GETS BACK ARE THE RESOURCE RECORD.
 ASSOCIATED WITH THAT NAME.
 MOST COMMAN IS IP ADDRESS.

10. DOMAIN NAME RESOLUTION
 THE QUERY IS SENT BY THE RESOLVER TO THE LOCAL DNS
SERVER,IF THE LOCAL SERVER CANNOT RESOLVE THE QUERY
IT ASK OTHER.

11. WORLD WIDE WEB(WWW)
 BACKGROUND:
 AN ARCHITECTURAL FRAME WORK FOR ACESSING LINKED
DOCUMENT SPREAD OUT OVER MILLIONS OF MACHINES.
 A REPOSITORY OF INFORMATION.
 INITIATED BY CERN.

12. ARCHITECTURAL OVERVIEW
 USES THE CONCEPT OF HYPER TEXT AND HYPER MEDIA.
 INFORMATION IS STORED IN A SET OF DOCUMENTS IN HYPER
TEXT.
 HYPERTEXT DOCUMENTS CONTAIN TEXT ONLY.
 HYPER MEDIA DOCUMENT CONTAIN PICTURES
,GRAPHICS,SOUNDS,ETC.

13. HOW WWW WORKS?
 THE BASIC MODEL OF HOW THE WWW WORK IS AS BELOW:
 BROWSER DISPLAYS A WEB PAGE ON CLIENT MACHINE .
 USER CLICK ON TEXT LINKED TO A PAGE ON ANY SERVER.
 BROWER SENDS A MESSAGE TO THAT SERVER.
 WHEN PAGE ARRIVES DISPLAYS IT.

14. ELECTRONIC MAIL (E-MAIL)
 BACKGROUND:
 MOST POPULAR NETWORK SERVICE.
 USED FOR SENDING MESSAGE.
 MOST WIDELY USED PROTOCOL IS SMTP(SIMPLE MAIL
TRANSFER PROTOCOL).

15. HOW TO SEND E-MAIL?
 USER CREATE MAIL THAT LOOKS VERY SIMILAR TO POSTAL
MAIL.
 CONTAINS FOUR PARTS:
 THE ENVELOPE:CONTAINS THE SENDER ADDRESS,RECEIVER
SUBJECT MESSAGE NEEDED TO TRANSMI T TO THE
DESTINATION.
 THE HEADER: CONTAINS PART OF THE ACTUAL MESSAGE.
 THE BODY : CONTAINS THE USUAL INFORMATION.
 THE SIGNETURE: CONTAINS INFORMATION ABOUT THE
SENDERS.

16. ADDRESS
 A MAIL MUST USES AN ADDRESSING SYSTEM WITH UNIQUE
ADDRESS.
 ADRESSING SYSTEM USED BY SMTP HAS TWO PARTS:
 A LOCAL PART
 A DOMAIN NAME
 EXAMPLE :nabendra.shrestha@gmail.com

17. ARCHITECTURAL OVERVIEW
 CONSIST OF TWO SUB-SYSTEM:
1. THE USER AGENT:
ALLOWS TO READ AND SEND EMAIL.
 SERVICES OF USER AGENT:
 COMPOSING MESSAGE
 READING MESSAGE
 REPLYING MESSAGE
 FORWARDING MESSAGE
 HANDELING MESSAGE
2. MESSAGE TRANSFER AGENT:
 MOVES MESSAGE FROM SOURCE TO DESTINATION.
 TRANSFER THROUGH(MTA) MAIL TRANSFER AGENT.
 TO SEND MAIL HAVE CLIENT MTA.
 TO RECEIVE MAIL HAVE SERVER MTA.

18. UNIFORM RESOURCE LOCATER(URL)
 BACKGROUND:
 URL stands for Uniform Resource Locator, which means it is a uniform
(same throughout the world) way to locate a resource (file or
document) on the Internet.
 USES :
 It specifies the address of a file uniquely.
 It helps to retrieve a file from the Server on which it resides.
 It uses String Characters that identify the Page.
 URLs consist of several parts:
 A protocol : Hypertext Transfer Protocol (HTTP).
 Some separation characters: ://

19. EXTENSIONS USED
 These are at the end of the domain name which has a
period main extensions :
 .com - Commercial use
 .net - network / Internet Service Provider use
 .org - Organizational use
 .edu - Educational use (Schools and universities)
 .mil - Military use
 .gov - Governmental use.

20. CONCLUSION
 FROM THIS PRESENTATION WE ALL CAME TO KNOW ABOUT
THE DOMAIN NAME SYSTEM(DNS),WORLD WIDE
WEB(WWW),ELECTRONIC MAIL(E-MAIL) AND UNIFORM
RESOURCE LOCATOR(URL) WHICH ALL ARE DESCRIBED
PREVIOUSLY.
 THANK YOU……!!!!!!