Domain Name System. Heng Sovannarith

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Domain Name System. Heng Sovannarith heng_sovannarith@yahoo.com"

Transcription

1 Domain Name System Heng Sovannarith

2 Introduc:on to DNS Domain Name System is a distributed database system that can be serve as the founda:on for name resolu:on in a TCP/IP Network. DNS used in the most of Internet sodware such as web browser and electronic mail program etc to locate servers and to resolve or map the user friendly name of the computer to an IP address. Example: - >

3 Introduc:on to DNS (cont.) We have : DNS Server DNS Database DNS Client Benefit of DNS: Convenience Name are easier than to remember numeric IP Addresses Consistency IP Addresses can be changed but server name can remain constant. Simplicity user can only learn only one naming conven:on to find resources either one Internet or intranet.

4 The Host File Long :me ago, the en:re Internet was small enough that network administrators could keep track all of it in a text file call Hosts file (that listed name and IP address of every host on the network). Each computer has it s own copy of the Host file. As the Internet grow, so did the Host file. We cannot keep record of name and IP address of the millions of hosts on the Internet in a single text file. Therefore, the DNS was invent On Windows, the host file is simply located in c:\windows \system32\drivers\etc\hosts

5 Domain and Domain Name Domain Name Space Domain Name Space provides the structure of DNS distributed databases and it has hiera:cal structure. Example: Each domain has its each unique name. DNS name ARE NOT case sensi:ve.

6 Domain and Domain Name (cont.) The name of each DNS node can be up to 63 characters long (not including the dot) and can be include le_ers, numbers, and hyphens. (No other special character are allowed) DNS is a hierarchical naming system that s similar to the hierarchical folder system used by Windows The DNS tree can be up to 127 levels deep.

7 Domain and Domain Name (cont.) Fully Qualified Domain Name (FQDN) If a domain name ends with a trailing dot, that trailing dot represented the root domain and the domain name is said to be a Fully Qualified Domain Name. Example:

8 Domain and Domain Name (cont.)

9 Root Server There are 13 Root Servers in the world.

10 Top- Level Domain There are the original generic top- level domain. Domain com edu gov int mil net org DescripKon Commercial organiza:ons Educa:onal ins:tu:ons Government ins:tu:ons Interna:onal treaty organiza:ons Military ins:tu:ons Network provider Noncommercial organiza:ons

11 Top- Level Domain (cont.) Because the com domain ballooned to an almost unmanageable size. The Internet authori:es approved seven new top- level domain. Most of domain in list become available in 2002 Domain aero biz coop info museum name pro DescripKon Aerospace authority Business Coopera:ves Informa:on sites Museums Individual users Professional organiza:ons

12 Name Resolu:on Process In Name Resolu:on Process, the query was sent to DNS Server for a request for name resolu:on. Type of Queries Itera&ve : An itera&ve name query is one in which a DNS client allows the DNS server to return the best answer it can give based on its cache or zone data. If the queried DNS server does not have an exact match for the queried name, the best possible informa:on it can return is a referral (that is, a pointer to a DNS server authorita:ve for a lower level of the domain namespace). The DNS client can then query the DNS server for which it obtained a referral. It con:nues this process un:l it locates a DNS server that is authorita:ve for the queried name, or un:l an error or :me- out condi:on is met.

13 Name Resolu:on Process (cont.) Recursive: Recursive name queries are generally made by a DNS client to a DNS server, or by a DNS server that is configured to pass unresolved name queries to another DNS server, in the case of a DNS server configured to use a forwarder.

14 Name Resolu:on Process

15 Caching DNS Caching provides faster query response and reduce network traffic. DNS Servers and Client have a Cache. Caching- Only Server: Although all DNS servers cache queries that they have resolved, caching- only servers are DNS servers that only perform queries, cache the answers, and return the results. They are not authorita:ve for any domains and the informa:on that they contain is limited to what has been cached while resolving queries.

16 Authorita:ve and Nonauthorita:ve DNS Server can be either Authorita&ve or Nonauthorita&ve. An authoritakve name server is a name server that gives answers that have been configured by an original source, for example, the domain administrator or by dynamic DNS methods, in contrast to answers that were obtained via a regular DNS query to another name server. Non authoritakve name servers do not contain copies of any domains. Instead they have a cache file that is constructed from all the DNS lookups it has performed in the past for which it has go_en an authorita:ve response. Non authorita:ve name servers can be either cache or forwarders.

17 Zone Zone is basically a Text File or Database that define what machines it know about in the namespace. There are two type of zones: The primary zones is the master copy of a zone. The database for primary zone is stored in local database of the DNS Server that host the primary zone. When the zone is stored in a file, by default the primary zone file is named zone_name.dns and it is located in the %windir% \System32\Dns folder on the server. The secondary zones is a read- only copy of a zone. When server host a secondary zone, the server doesn t store a local copy of the zone data. Instead, it obtain its copy of the zone from the zones primary server by using a process called zone transfer.

18 Zone (cont.)

19 Zone Files and Resource Record Zone files organize the zone records for domain names and subdomains in a DNS server. Every domain name and subdomain has a zone file, and each zone file contains zone records. These files, editable in any plain text editor, hold the DNS informa:on linking domain names and subdomains to IP addresses. Zone files usually contain several different zone records.

20 Zone Files and Resource Record Type Name DescripKon SOA Start Of Authority Iden:fies a zone NS Name Server Iden:fies a name server that is authoriza:on for zone A Address Map a fully qualifies domain name to a IP Address CNAME Canonical Name Creates an alias for a fully qualified domain name MX Mail Exchange Iden:fies the mail server for a domain PTR Pointer Maps an IP Address to a fully qualified domain name for reverse lookups

21 Zone Files and Resource Record (cont.) SOA records: Required for every zone file, the SOA record contains caching informa:on, the zone administrator s address, and the master name server for the zone. The SOA also contains a number incremented with each update. As this number updates, it triggers the DNS to reload the zone data. NS records: Name Server (NS) records iden:fy the name server that are authorita:ve for the zone. Every zone must have at least on NS record. Using two or more NS record is be_er so that if the first name server is unavailable, the zone will s:ll be accessible.

22 Zone Files and Resource Record (cont.) A records: Address (A) record are the meat of the zone file. They provide the IP address for each of the hosts that you want to make accessible via DNS. CNAME records: A Canonical Name (CNAME) records create an alias for a fully qualified domain name. When user a_empt to access a domain name that is actually an alias, the DNS system subs:tutes the read domain name for the alias.

23 Zone Files and Resource Record (cont.) PRT Record: A Pointer (PTR) record is a the opposite of an address record: it provides the full qualified domain name for a given address. MX records: Mail Exchange (MX) records iden:fy the mail server for a domain. It provides the mail server informa:on for that zone to deliver to the correct loca:on.

24 Reverse Lookup Zone Normally DNS queries ask a name server to provide that corresponds to a full qualified domain name. It is called a forward look up. A reverse lookup is the opposite of a forward lookup: it return FQDN of a host based on its IP Address. Reverse lookup are possible because a special domain call in- addr.arpa. To enable a reverse look up for a par:cular IP Address, all you have to do is create a PTR record in a reverse lookup zone.

25 Installing DNS Go to Server Manager - > Add role - > Choose DNS Server - > Next - > Next - > Finish

26 Configuring DNS right- click the DNS server and choose ProperKes to show the dialog box shown in image below. This dialog box enables you to configure a comprehensive range of server- specific proper:es.

27 Configuring DNS (cont.) Forwarder The act of forwarding refers to the relaying of a DNS request from one server to another one when the first server is unable to process the request. It is a DNS Server to which other DNS Server forward queries. Type of Forwarders Standard Condi:onal

28 Configuring DNS (cont.)

29 Configuring DNS (cont.)

30 Configuring DNS (cont.) Select network interface which you want to provide DNS Service

31 Configuring DNS (cont.) Check the 13 Root DNS but do not do any change on them

32 Configuring DNS (cont.) If the DNS cannot find do resolve for a par:cular domain name and you want to forward it to other DNS Servers such ISP s DNS server or Google public DNS ( ), you list them in Forwarders

33 Configuring DNS (cont.)

34 Configuring DNS (cont.) To create a new Zone

35 Configuring DNS (cont.) Select the Primary Zone

36 Configuring DNS (cont.)

37 Configuring DNS (cont.) Put the domain name

38 Configuring DNS (cont.) Allow both nonsecure and secure dynamic update

39 Finish Configuring DNS (cont.)

40 Configuring DNS (cont.) You can check the SOA record

41 Configuring DNS (cont.) In SOA record Serial Number : The serial number of a zone. Secondary zones user this value to determine whether they need to ini:ate a zone transfer to update their copy of zone. Responsible Person: An e- mail address of the person responsible for this zone. Refresh Interval: a :me interval that specifies how oden a secondary server should check whether the zone need to be refreshed. A typical value is 1 hours Expire ATer: A :me interval that specifies how long a should a secondary server should keep the zone data bfor discarding it. A typical value is one day. Minimum (default) TTL: A :me interval that specifies the TTL value use for a zone resource records that omit the TTL field. Default value is one hour.

42 Configuring DNS (cont.) You can add the A record, CNAME record by right click on Zone and choose them.

43 Configuring DNS (cont.) To add Name Server, right click on Zone and choose Property and then select the Name Servers tab.

44 Configuring DNS (cont.) To add PTR record, click on Reverse Lookup Zone and choose new Zone

45 Configuring DNS (cont.)

46 Configuring DNS (cont.)

47 Configuring DNS (cont.)

48 Configuring DNS (cont.) Put the 3 octet of IP Address in your Zone

49 Configuring DNS (cont.)

50 Finish :P Configuring DNS (cont.)

51 Configuring DNS (cont.) In the Server To clear DNS Cache: C:\ipconfig /clearcache In the client machine: To resolve a Domain name: C:\nslookup rith.local To clear DNS Cache: C:\ipconfig /flushdns To display DNS Cache: C:\ipconfig /displaydns To Turn off DNS Cache: C:\net stop dnscache

Copyright 2012 http://itfreetraining.com

Copyright 2012 http://itfreetraining.com In order to find resources on the network, computers need a system to look up the location of resources. This video looks at the DNS records that contain information about resources and services on the

More information

Lecture 2 CS 3311. An example of a middleware service: DNS Domain Name System

Lecture 2 CS 3311. An example of a middleware service: DNS Domain Name System Lecture 2 CS 3311 An example of a middleware service: DNS Domain Name System The problem Networked computers have names and IP addresses. Applications use names; IP uses for routing purposes IP addresses.

More information

Motivation. Domain Name System (DNS) Flat Namespace. Hierarchical Namespace

Motivation. Domain Name System (DNS) Flat Namespace. Hierarchical Namespace Motivation Domain Name System (DNS) IP addresses hard to remember Meaningful names easier to use Assign names to IP addresses Name resolution map names to IP addresses when needed Namespace set of all

More information

How to Configure the Windows DNS Server

How to Configure the Windows DNS Server Windows 2003 How to Configure the Windows DNS Server How to Configure the Windows DNS Server Objective This document demonstrates how to configure domains and record on the Windows 2003 DNS Server. Windows

More information

How to Add Domains and DNS Records

How to Add Domains and DNS Records How to Add Domains and DNS Records Configure the Barracuda NextGen X-Series Firewall to be the authoritative DNS server for your domains or subdomains to take advantage of Split DNS or dead link detection.

More information

Install and configure a DNS server in Windows Server 2008?

Install and configure a DNS server in Windows Server 2008? Install and configure a DNS server in Windows Server 2008? Version 1.0 April 15, 2008 By Steven S. Warren As many of you are probably aware, the Domain Name System (DNS) is now the name resolution system

More information

Windows 2008 Server. Domain Name System Administración SSII

Windows 2008 Server. Domain Name System Administración SSII Windows 2008 Server Domain Name System Administración SSII Contenidos Introducción Configuración DNS Transferencia de zona Herramientas DNS Introducción Domain Name System is a hierarchical distributed

More information

DNS Domain Name System

DNS Domain Name System Domain Name System DNS Domain Name System The domain name system is usually used to translate a host name into an IP address Domain names comprise a hierarchy so that names are unique, yet easy to remember.

More information

DNS and E-mail Interface User Guide

DNS and E-mail Interface User Guide DNS and E-mail Interface User Guide Document Revision 04 // 2012 www.twcbc.com back back to TOC to TOC Header Text and Info Table of Contents 1. Introduction 3 2. Accessing the Application 4 3. Working

More information

Installing and Setting up Microsoft DNS Server

Installing and Setting up Microsoft DNS Server Training Installing and Setting up Microsoft DNS Server Introduction Versions Used Windows Server 2003 Setup Used i. Server Name = martini ii. Credentials: User = Administrator, Password = password iii.

More information

Understand Names Resolution

Understand Names Resolution Understand Names Resolution Lesson Overview In this lesson, you will learn about: Domain name resolution Name resolution process steps DNS WINS Anticipatory Set 1. List the host name of 4 of your favorite

More information

DNS. Computer networks - Administration 1DV202. fredag 30 mars 12

DNS. Computer networks - Administration 1DV202. fredag 30 mars 12 DNS Computer networks - Administration 1DV202 DNS History Who needs DNS? The DNS namespace How DNS works The DNS database The BIND software Server and client configuration The history of DNS RFC 882 and

More information

The Domain Name System (DNS)

The Domain Name System (DNS) The Domain Name System (DNS) Columbus, OH 43210 Jain@CIS.Ohio-State.Edu http://www.cis.ohio-state.edu/~jain/ 24-1 Overview Naming hierarchy hierarchy Name resolution Other information in name servers 24-2

More information

MCTS Guide to Configuring Microsoft Windows Server 2008 Active Directory. Chapter 9: Configuring DNS for Active Directory

MCTS Guide to Configuring Microsoft Windows Server 2008 Active Directory. Chapter 9: Configuring DNS for Active Directory MCTS Guide to Configuring Microsoft Windows Server 2008 Active Directory Chapter 9: Configuring DNS for Active Directory Objectives Describe the structure of Domain Name System Install and use the DNS

More information

Application Protocols in the TCP/IP Reference Model

Application Protocols in the TCP/IP Reference Model Application Protocols in the TCP/IP Reference Model File Transfer E-Mail Network Management WWW Virtual Terminal Name Service File Transfer HTTP FTP Telnet SMTP DNS SNMP TFTP Internet protocols TCP UDP

More information

Application Protocols in the TCP/IP Reference Model. Application Protocols in the TCP/IP Reference Model. DNS - Concept. DNS - Domain Name System

Application Protocols in the TCP/IP Reference Model. Application Protocols in the TCP/IP Reference Model. DNS - Concept. DNS - Domain Name System Application Protocols in the TCP/IP Reference Model Application Protocols in the TCP/IP Reference Model File Transfer E-Mail Network Management Protocols of the application layer are common communication

More information

- Domain Name System -

- Domain Name System - 1 Name Resolution - Domain Name System - Name resolution systems provide the translation between alphanumeric names and numerical addresses, alleviating the need for users and administrators to memorize

More information

A DNS Tutorial. Copyright

A DNS Tutorial.  Copyright http://ntrg.cs.tcd.ie/undergrad/4ba2/multicast/ Copyright Table of Contents What is a DNS?... 3 Why do we need a DNS?... 3 Why do computers prefer addresses based on numbers?... 3 What is a Domain Name,

More information

Vorlesung Kommunikationsnetze Domain Name System

Vorlesung Kommunikationsnetze Domain Name System Picture 15 13 Vorlesung Kommunikationsnetze Domain Name System Prof. Dr. H. P. Großmann mit B. Wiegel sowie A. Schmeiser und M. Rabel Sommersemester 2009 Institut für Organisation und Management von Informationssystemen

More information

Talk-101 User Guide. DNSGate

Talk-101 User Guide. DNSGate Talk-101 User Guide DNSGate What is DNSGate? DNSGate is a management interface to allow you to make DNS changes to your domain. The interface supports A, CNAME, MX and TXT records. What is DNS? DNS stands

More information

CS3250 Distributed Systems

CS3250 Distributed Systems CS3250 Distributed Systems Lecture 4 More on Network Addresses Domain Name System DNS Human beings (apart from network administrators and hackers) rarely use IP addresses even in their human-readable dotted

More information

Understanding DNS (the Domain Name System)

Understanding DNS (the Domain Name System) Understanding DNS (the Domain Name System) A white paper by Incognito Software January, 2007 2007 Incognito Software Inc. All rights reserved. Understanding DNS (the Domain Name System) Introduction...2

More information

Domain Name System (DNS)

Domain Name System (DNS) Lab Objectives Domain Name System (DNS) Acquiring skills related to the Domain Name System (DNS) functions Practical studying of DNS protocol in the process of its functioning Background Information DNS

More information

ECE 4321 Computer Networks. Network Programming

ECE 4321 Computer Networks. Network Programming ECE 4321 Computer Networks Network Programming Name Space System.Net Domain Name System (DNS) To resolve computer naming Host database is split up and distributed among multiple systems on the Internet

More information

Introduction to DNS CHAPTER 5. In This Chapter

Introduction to DNS CHAPTER 5. In This Chapter 297 CHAPTER 5 Introduction to DNS Domain Name System (DNS) enables you to use hierarchical, friendly names to easily locate computers and other resources on an IP network. The following sections describe

More information

HTG XROADS NETWORKS. Network Appliance How To Guide: EdgeDNS. How To Guide

HTG XROADS NETWORKS. Network Appliance How To Guide: EdgeDNS. How To Guide HTG X XROADS NETWORKS Network Appliance How To Guide: EdgeDNS How To Guide V 3. 2 E D G E N E T W O R K A P P L I A N C E How To Guide EdgeDNS XRoads Networks 17165 Von Karman Suite 112 888-9-XROADS V

More information

DNS. Computer Networks. Seminar 12

DNS. Computer Networks. Seminar 12 DNS Computer Networks Seminar 12 DNS Introduction (Domain Name System) Naming system used in Internet Translate domain names to IP addresses and back Communication works on UDP (port 53), large requests/responses

More information

Introduction to the Domain Name System

Introduction to the Domain Name System CHAPTER 14 The Domain Name System (DNS) handles the growing number of Internet users. DNS translates names, such as www.cisco.com, into IP addresses, such as 192.168.40.0 (or the more extended IPv6 addresses),

More information

DNS : Domain Name System

DNS : Domain Name System 1/30 DNS : Domain Name System Surasak Sanguanpong nguan@.ac.th http://www...ac.th/~nguan Last updated: May 24, 1999 Outline 2/30 DNS basic name space name resolution process protocol configurations Why

More information

How to set up the Integrated DNS Server for Inbound Load Balancing

How to set up the Integrated DNS Server for Inbound Load Balancing How to set up the Integrated DNS Server for Introduction Getting Started Peplink Balance has a built-in DNS server for inbound link load balancing. You can delegate a domain s NS/SOA records, e.g. www.mycompany.com,

More information

Domain Name System. 188lecture12.ppt. Pirkko Kuusela, Markus Peuhkuri, Jouni Karvo

Domain Name System. 188lecture12.ppt. Pirkko Kuusela, Markus Peuhkuri, Jouni Karvo Domain Name System 88lecture2.ppt Pirkko Kuusela, Markus Peuhkuri, Jouni Karvo S-38.88 - Computer Networks - Spring 2003 Outline What and why? Structure of DNS Management of Domain Names Name Service in

More information

How To Guide Edge Network Appliance How To Guide:

How To Guide Edge Network Appliance How To Guide: How To Guide Edge Network Appliance How To Guide: ActiveDNS v 4.01 Edge Network Appliance How To Guide: ActiveDNS 2007 XRoads Networks 17165 Von Karman, Suite 112 888-9-XROADS v 4.01 updated 09/11/07 Table

More information

Domain Name System. CS 571 Fall 2006. 2006, Kenneth L. Calvert University of Kentucky, USA All rights reserved

Domain Name System. CS 571 Fall 2006. 2006, Kenneth L. Calvert University of Kentucky, USA All rights reserved Domain Name System CS 571 Fall 2006 2006, Kenneth L. Calvert University of Kentucky, USA All rights reserved DNS Specifications Domain Names Concepts and Facilities RFC 1034, November 1987 Introduction

More information

The Domain Name System

The Domain Name System DNS " This is the means by which we can convert names like news.bbc.co.uk into IP addresses like 212.59.226.30 " Purely for the benefit of human users: we can remember numbers (e.g., telephone numbers),

More information

Application Protocols in the TCP/IP Reference Model. Application Protocols in the TCP/IP Reference Model. DNS - Domain Name System

Application Protocols in the TCP/IP Reference Model. Application Protocols in the TCP/IP Reference Model. DNS - Domain Name System Application Protocols in the TCP/IP Reference Model Application Protocols in the TCP/IP Reference Model File Transfer E-Mail Network Management Protocols of the application layer are common communication

More information

Domain Name System (DNS) Fundamentals

Domain Name System (DNS) Fundamentals Domain Name System (DNS) Fundamentals Mike Jager Network Startup Resource Center mike.jager@synack.co.nz These materials are licensed under the Creative Commons Attribution-NonCommercial 4.0 International

More information

The Domain Name System (DNS)

The Domain Name System (DNS) The Domain Name System (DNS) Each Internet host is assigned a host name and an IP address Host names are structured character strings, e.g., www.cs.iastate.edu IP addresses are 32 bit integers, e.g., 129.186.3.6

More information

KB259302 - Windows 2000 DNS Event Messages 1 Through 1614

KB259302 - Windows 2000 DNS Event Messages 1 Through 1614 Page 1 of 6 Knowledge Base Windows 2000 DNS Event Messages 1 Through 1614 PSS ID Number: 259302 Article Last Modified on 10/29/2003 The information in this article applies to: Microsoft Windows 2000 Server

More information

DNS Domain Name System

DNS Domain Name System DNS Domain Name System Domain names and IP addresses People prefer to use easy-to-remember names instead of IP addresses Domain names are alphanumeric names for IP addresses e.g., neon.cs.virginia.edu,

More information

Electronic Mail. The protocols used for Internet can be divided into three broad categories. transfer program. application.

Electronic Mail. The protocols used for Internet  can be divided into three broad categories. transfer program. application. Electronic Mail The protocols used for Internet email can be divided into three broad categories transfer program interface application interface application 33 The Simple Mail Transfer Protocol (SMTP)

More information

Lesson 13: DNS Security. Javier Osuna josuna@gmv.com GMV Head of Security and Process Consulting Division

Lesson 13: DNS Security. Javier Osuna josuna@gmv.com GMV Head of Security and Process Consulting Division Lesson 13: DNS Security Javier Osuna josuna@gmv.com GMV Head of Security and Process Consulting Division Introduction to DNS The DNS enables people to use and surf the Internet, allowing the translation

More information

2 HDE Controller X DNS Server Manual

2 HDE Controller X DNS Server Manual DNS Server Manual 2 HDE Controller X DNS Server Manual Please note that this user manual may be subjected to change due to product upgrades without any prior notice. HDE and HDE Controller is a registered

More information

INTERNET DOMAIN NAME SYSTEM

INTERNET DOMAIN NAME SYSTEM INTERNET DOMAIN NAME SYSTEM http://www.tutorialspoint.com/internet_technologies/internet_domain_name_system.htm Copyright tutorialspoint.com Overview When DNS was not into existence, one had to download

More information

DNS. The Root Name Servers. DNS Hierarchy. Computer System Security and Management SMD139. Root name server. .se name server. .

DNS. The Root Name Servers. DNS Hierarchy. Computer System Security and Management SMD139. Root name server. .se name server. . Computer System Security and Management SMD139 Lecture 5: Domain Name System Peter A. Jonsson DNS Translation of Hostnames to IP addresses Hierarchical distributed database DNS Hierarchy The Root Name

More information

Domain Name System Security

Domain Name System Security Domain Name System Security Guevara Noubir Network Security Northeastern University 1 Domain Name System DNS is a fundamental applica=on layer protocol Not visible but invoked every =me a remote site is

More information

Managing Name Resolution

Managing Name Resolution 3 CHAPTER THREE Managing Name Resolution Terms you ll need to understand: Windows Internet Naming Service (WINS) WINS Proxy Agent LMHOSTS Tombstoning Persistent Connections Push/pull partner Hostnames

More information

Domain Name System 2015-04-28 17:49:44 UTC. 2015 Citrix Systems, Inc. All rights reserved. Terms of Use Trademarks Privacy Statement

Domain Name System 2015-04-28 17:49:44 UTC. 2015 Citrix Systems, Inc. All rights reserved. Terms of Use Trademarks Privacy Statement Domain Name System 2015-04-28 17:49:44 UTC 2015 Citrix Systems, Inc. All rights reserved. Terms of Use Trademarks Privacy Statement Contents Domain Name System... 4 Domain Name System... 5 How DNS Works

More information

Domain Name Server. Training Division National Informatics Centre New Delhi

Domain Name Server. Training Division National Informatics Centre New Delhi Domain Name Server Training Division National Informatics Centre New Delhi Domain Name Service (DNS) I. History of DNS II. DNS structure and its components III. Functioning of DNS IV. Possible Configurations

More information

Copyright International Business Machines Corporation 2001. All rights reserved. US Government Users Restricted Rights Use, duplication or disclosure

Copyright International Business Machines Corporation 2001. All rights reserved. US Government Users Restricted Rights Use, duplication or disclosure iseries DNS iseries DNS Copyright International Business Machines Corporation 2001. All rights reserved. US Government Users Restricted Rights Use, duplication or disclosure restricted by GSA ADP Schedule

More information

Introduction to Network Operating Systems

Introduction to Network Operating Systems As mentioned earlier, different layers of the protocol stack use different kinds of addresses. We can now see that the Transport Layer (TCP) uses port addresses to route data to the correct process, the

More information

Fig 1A portion of the Internet domain name space.

Fig 1A portion of the Internet domain name space. 1 Asst. Lecturar ahmed S. Kareem DNS The Domain Name System Although programs theoretically could refer to hosts, mailboxes, and other resources by their network (e.g., IP) addresses, these addresses are

More information

Chapter 23 The Domain Name System (DNS)

Chapter 23 The Domain Name System (DNS) CSC521 Communication Protocols 網 路 通 訊 協 定 Chapter 23 The Domain Name System (DNS) 吳 俊 興 國 立 高 雄 大 學 資 訊 工 程 學 系 Outline 1. Introduction 2. Names For Machines 3. Flat Namespace 4. Hierarchical Names 5.

More information

CS3600 SYSTEMS AND NETWORKS

CS3600 SYSTEMS AND NETWORKS CS3600 SYSTEMS AND NETWORKS FALL 2011 Lecture 19: DNS Prof. Alan Mislove (amislove@ccs.neu.edu) Slides used with permissions from Edward W. Knightly, T. S. Eugene Ng, Ion Stoica, Hui Zhang Human Involvement

More information

Part 5 DNS Security. SAST01 An Introduction to Information Security 2015-09-21. Martin Hell Department of Electrical and Information Technology

Part 5 DNS Security. SAST01 An Introduction to Information Security 2015-09-21. Martin Hell Department of Electrical and Information Technology SAST01 An Introduction to Information Security Part 5 DNS Security Martin Hell Department of Electrical and Information Technology How DNS works Amplification attacks Cache poisoning attacks DNSSEC 1 2

More information

Domain Name Servers. Domain Types WWW host names. Internet Names. COMP476 Networked Computer Systems. Domain Name Servers

Domain Name Servers. Domain Types WWW host names. Internet Names. COMP476 Networked Computer Systems. Domain Name Servers Domain Name Servers COMP76 Networked Computer Systems Internet Names Hierarchical starting from the right host.subnet.organization.type Names are case insensitive and can be in either upper or lower case.

More information

Administrasi dan Manajemen Jaringan

Administrasi dan Manajemen Jaringan Administrasi dan Manajemen Jaringan 3. Domain Name System (DNS) M. Udin Harun Al Rasyid, Ph.D http://lecturer.eepis-its.edu/~udinharun udinharun@eepis-its.edu Lab Jaringan Komputer (C-307) Table of Contents

More information

The Application Layer. CS158a Chris Pollett May 9, 2007.

The Application Layer. CS158a Chris Pollett May 9, 2007. The Application Layer CS158a Chris Pollett May 9, 2007. Outline DNS E-mail More on HTTP The Domain Name System (DNS) To refer to a process on the internet we need to give an IP address and a port. These

More information

Networking Domain Name System

Networking Domain Name System System i Networking Domain Name System Version 5 Release 4 System i Networking Domain Name System Version 5 Release 4 Note Before using this information and the product it supports, read the information

More information

Distributed Systems. 22. Naming. 2013 Paul Krzyzanowski. Rutgers University. Fall 2013

Distributed Systems. 22. Naming. 2013 Paul Krzyzanowski. Rutgers University. Fall 2013 Distributed Systems 22. Naming Paul Krzyzanowski Rutgers University Fall 2013 November 21, 2013 2013 Paul Krzyzanowski 1 My 15 MacBook Pro The rightmost computer on my desk Paul s aluminum laptop, but

More information

HTG XROADS NETWORKS. Network Appliance How To Guide: DNS Delegation. How To Guide

HTG XROADS NETWORKS. Network Appliance How To Guide: DNS Delegation. How To Guide HTG X XROADS NETWORKS Network Appliance How To Guide: DNS Delegation How To Guide DNS Delegation (The Simple Redundancy Solution) The key requirement when performing DNS based network redundancy and load

More information

THE DOMAIN NAME SYSTEM DNS

THE DOMAIN NAME SYSTEM DNS Announcements THE DOMAIN NAME SYSTEM DNS Internet Protocols CSC / ECE 573 Fall, 2005 N. C. State University copyright 2005 Douglas S. Reeves 2 Today s Lecture I. Names vs. Addresses II. III. IV. The Namespace

More information

L4 Domain Name System (DNS)

L4 Domain Name System (DNS) L4 Domain Name System (DNS) by T.S.R.K. Prasad EA C451 Internetworking Technologies 19/01/2013 References / Acknowledgements Sec 2.5: DNS, [Kurose] Sec 9.3.1: Name Service (DNS), [Peterson] Sec 12.3: DNS,

More information

Distributed Systems. 09. Naming. Paul Krzyzanowski. Rutgers University. Fall 2015

Distributed Systems. 09. Naming. Paul Krzyzanowski. Rutgers University. Fall 2015 Distributed Systems 09. Naming Paul Krzyzanowski Rutgers University Fall 2015 October 7, 2015 2014-2015 Paul Krzyzanowski 1 Naming things Naming: map names to objects Helps with using, sharing, and communicating

More information

THE MASTER LIST OF DNS TERMINOLOGY. v 2.0

THE MASTER LIST OF DNS TERMINOLOGY. v 2.0 THE MASTER LIST OF DNS TERMINOLOGY v 2.0 DNS can be hard to understand and if you re unfamiliar with the terminology, learning more about DNS can seem as daunting as learning a new language. To help people

More information

Services: DNS domain name system

Services: DNS domain name system Services: DNS domain name system David Morgan Buying numbers and names numbers are IP addresses you buy them from an ISP the ISP makes sure those addresses go to your place the names are domain names you

More information

5 Configuring a DNS Infrastructure

5 Configuring a DNS Infrastructure 5 Configuring a DNS Infrastructure Exam Objectives in this Chapter: Configure a DNS server. Configure DNS zone options. Configure DNS forwarding. Manage DNS zone settings. Manage DNS server options. Why

More information

DNS: How it works. DNS: How it works (more or less ) DNS: How it Works. Technical Seminars Spring 2010 1. Paul Semple psemple@rm.

DNS: How it works. DNS: How it works (more or less ) DNS: How it Works. Technical Seminars Spring 2010 1. Paul Semple psemple@rm. DNS: How it works Paul Semple psemple@rm.com DNS: How it works (more or less ) Paul Semple psemple@rm.com 1 Objectives What DNS is and why we need it DNS on Windows Server networks / Community Connect

More information

Domain Name System (DNS) Session-1: Fundamentals. Ayitey Bulley abulley@ghana.com

Domain Name System (DNS) Session-1: Fundamentals. Ayitey Bulley abulley@ghana.com Domain Name System (DNS) Session-1: Fundamentals Ayitey Bulley abulley@ghana.com Computers use IP addresses. Why do we need names? Names are easier for people to remember Computers may be moved between

More information

CS5008: Internet Computing

CS5008: Internet Computing CS5008: Internet Computing Lecture 12: Domains and DNS A. O Riordan, 2009, latest revision 2016 Some slides based on Fitzgerald and Dennis textbook Domains Purpose of Domains: Domains are administrative

More information

How to Configure DNS Zones

How to Configure DNS Zones How to Configure DNS Zones The Barracuda NG Firewall DNS configuration object contains two predefined zones: _template and. To be able to edit and specify DNS zones within the Barracuda NG Firewall DNS

More information

Internet-Praktikum I Lab 3: DNS

Internet-Praktikum I Lab 3: DNS Kommunikationsnetze Internet-Praktikum I Lab 3: DNS Mark Schmidt, Andreas Stockmayer Sommersemester 2015 kn.inf.uni-tuebingen.de Motivation for the DNS Problem IP addresses hard to remember for humans

More information

Names vs. Addresses. Flat vs. Hierarchical Space. Domain Name System (DNS) Computer Networks. Lecture 5: Domain Name System

Names vs. Addresses. Flat vs. Hierarchical Space. Domain Name System (DNS) Computer Networks. Lecture 5: Domain Name System Names vs. Addresses Computer Networks Lecture 5: Domain Name System Names are easier for human to remember www.umich.edu vs. 141.213.4.4 Addresses can be changed without changing names move www.umich.edu

More information

Hostnames. HOSTS.TXT was a bottleneck. Once there was HOSTS.TXT. CSCE515 Computer Network Programming. Hierarchical Organization of DNS

Hostnames. HOSTS.TXT was a bottleneck. Once there was HOSTS.TXT. CSCE515 Computer Network Programming. Hierarchical Organization of DNS Hostnames CSCE 515: Computer Network Programming ------ Address Conversion Function and DNS RFC 1034, RFC 1035 Wenyuan Xu http://www.cse..edu/~wyxu/ce515f07.html Department of Computer Science and Engineering

More information

Intro to djbdns. A DNS server besides BIND. Nathan Straz. nate@techie.com. Intro to djbdns p.1/21

Intro to djbdns. A DNS server besides BIND. Nathan Straz. nate@techie.com. Intro to djbdns p.1/21 Intro to djbdns A DNS server besides BIND Nathan Straz nate@techie.com Intro to djbdns p.1/21 Today s Topics Overview of DNS Overview of djbdns djbdns by example local cache network cache private domain

More information

DNS + DHCP. Michael Tsai 2015/04/27

DNS + DHCP. Michael Tsai 2015/04/27 DNS + DHCP Michael Tsai 2015/04/27 lubuntu.ova http://goo.gl/bax8b8 DNS + DHCP DNS: domain name < > IP address DHCP: gives you a IP + configuration when you joins a new network DHCP = Dynamic Host Configuration

More information

Chapter 7 Implementing Domain Name System (DNS)

Chapter 7 Implementing Domain Name System (DNS) [Previous] [Next] Chapter 7 Implementing Domain Name System (DNS) About This Chapter In this chapter, you will learn how Domain Name System (DNS) is used to resolve host names on your local area network

More information

DNS and BIND. David White

DNS and BIND. David White DNS and BIND David White DNS: Backbone of the Internet Translates Domains into unique IP Addresses i.e. developcents.com = 66.228.59.103 Distributed Database of Host Information Works seamlessly behind

More information

Introduction to DNS and Application Issues related to DNS. Kirk Farquhar

Introduction to DNS and Application Issues related to DNS. Kirk Farquhar Introduction to DNS and Application Issues related to DNS Kirk Farquhar 1 Content What is DNS? How it all works Setting up your domain Creating your nameserver files The Resolver Testing Firewall configuration

More information

19 Domain Name System (DNS)

19 Domain Name System (DNS) CHAPTER 9 Domain Name System (DNS) I n this chapter, we discuss the second application program, Domain Name System (DNS). DNS is a client/server application program used to help other application programs.

More information

NET0183 Networks and Communications

NET0183 Networks and Communications NET0183 Networks and Communications Lecture 25 DNS Domain Name System 8/25/2009 1 NET0183 Networks and Communications by Dr Andy Brooks DNS is a distributed database implemented in a hierarchy of many

More information

Goal of this session

Goal of this session DNS refresher Overview Goal of this session What is DNS? How is DNS built and how does it work? How does a query work? Record types Caching and Authoritative Delegation: domains vs zones Finding the error:

More information

Implementing Domain Name Service (DNS)

Implementing Domain Name Service (DNS) Implementing Domain Name Service (DNS) H C A 1 P T E R ITINERARY Objective 1.01 Objective 1.02 Objective 1.03 Install and Configure DNS for Active Directory Integrate Active Directory DNS Zones with Existing

More information

DNS Name Resolution 1. INTRODUCTION. 2. Steps in the Lab. 3. Configuring the Network

DNS Name Resolution 1. INTRODUCTION. 2. Steps in the Lab. 3. Configuring the Network DNS Name Resolution 1. INTRODUCTION If I type http://74.125.227.114/ on a web browser I will get the Google homepage. This is the IP address of this web site (server that gives me this website). This is

More information

Module 2. Configuring and Troubleshooting DNS. Contents:

Module 2. Configuring and Troubleshooting DNS. Contents: Configuring and Troubleshooting DNS 2-1 Module 2 Configuring and Troubleshooting DNS Contents: Lesson 1: Installing the DNS Server Role 2-3 Lesson 2: Configuring the DNS Server Role 2-9 Lesson 3: Configuring

More information

INTRODUCTION TO DNS or, how computers handle our predilection for names over IP addresses TECH SPECS. Instructor: Nathan Isburgh

INTRODUCTION TO DNS or, how computers handle our predilection for names over IP addresses TECH SPECS. Instructor: Nathan Isburgh INTRODUCTION TO DNS or, how computers handle our predilection for names over IP addresses TECH SPECS Instructor: Nathan Isburgh instructor@edgecloud.com 4 hours, lecture/lab format Two 10 minute breaks

More information

Module 4: Resolving Host Names by Using Domain Name System

Module 4: Resolving Host Names by Using Domain Name System Module 4: Resolving Host Names by Using Domain Name System Contents Overview 1 Multimedia: The Role of DNS in the Network Infrastructure 2 Lesson: Installing the DNS Server Service 3 Lesson: Configuring

More information

Understanding DNS By Robert Sterler

Understanding DNS By Robert Sterler Understanding DNS By Robert Sterler DNS is a locator service and stands for Domain Naming System. DNS provides a mechanism for locating computers either by friendly name or IP address. DNS is an integral

More information

The Use of DNS Resource Records

The Use of DNS Resource Records International Journal of Advances in Electrical and Electronics Engineering 230 Available online at www.ijaeee.com & www.sestindia.org/volume-ijaeee/ ISSN: 2319-1112 Simar Preet Singh Systems Engineer,

More information

Inbound Load Balance. User Manual

Inbound Load Balance. User Manual Inbound Load Balance User Manual 1 Inbound Load Balance Qno Firewall/Router not only supports efficient Outbound Load Balance, but Inbound Load Balance. It distributes inbound traffic equally to every

More information

THE MASTER LIST OF DNS TERMINOLOGY. First Edition

THE MASTER LIST OF DNS TERMINOLOGY. First Edition THE MASTER LIST OF DNS TERMINOLOGY First Edition DNS can be hard to understand and if you re unfamiliar with the terminology, learning more about DNS can seem as daunting as learning a new language. To

More information

Networking Domain Name System

Networking Domain Name System System i Networking Domain Name System Version 6 Release 1 System i Networking Domain Name System Version 6 Release 1 Note Before using this information and the product it supports, read the information

More information

CSE 265: System & Network Administration

CSE 265: System & Network Administration CSE 265: System & Network Administration DNS The Domain Name System History of DNS What does DNS do? The DNS namespace BIND software How DNS works DNS database Testing and debugging (tools) DNS History

More information

DOMAIN NAME SYSTEM. Shipra Dey Computer Science & Engineering iamshipradey@gmail.com

DOMAIN NAME SYSTEM. Shipra Dey Computer Science & Engineering iamshipradey@gmail.com DOMAIN NAME SYSTEM Shipra Dey Computer Science & Engineering iamshipradey@gmail.com Siladtya Bhaumik Computer Science & Engineering siladtyabhaumik@gmail.com Abstract: This document briefly describes different

More information

Application Layer: DNS

Application Layer: DNS Application Layer: DNS Prof. Andrzej Duda duda@imag.fr http://duda.imag.fr 1 Overview Learn about protocols by examining popular application-level protocols DNS - name service 2 Applications and application-layer

More information

Section 1 Overview... 4. Section 2 Home... 5

Section 1 Overview... 4. Section 2 Home... 5 ecogent User Guide 2012 Cogent Communications, Inc. All rights reserved. Every effort has been made to ensure that the information in this User Guide is accurate. Information in this document is subject

More information

Computer Networks: Domain Name System

Computer Networks: Domain Name System Computer Networks: Domain Name System Domain Name System The domain name system (DNS) is an application-layer protocol for mapping domain names to IP addresses DNS www.example.com 208.77.188.166 http://www.example.com

More information

IPv6 support in the DNS

IPv6 support in the DNS IPv6 support in the DNS How important is the DNS? Getting the IP address of the remote endpoint is necessary for every communication between TCP/IP applications Humans are unable to memorize millions of

More information

Distributed Name Services

Distributed Name Services Distributed Name Services A distinct service that is used by client processes to obtain attributes such as addresses of resources or objects when given their names Introducing Name Services Naming is fundamental

More information

netkit lab dns Università degli Studi Roma Tre Dipartimento di Informatica e Automazione Computer Networks Research Group Version Author(s)

netkit lab dns Università degli Studi Roma Tre Dipartimento di Informatica e Automazione Computer Networks Research Group Version Author(s) Università degli Studi Roma Tre Dipartimento di Informatica e Automazione Computer Networks Research Group netkit lab dns Version Author(s) E-mail Web Description 2.2 G. Di Battista, M. Patrignani, M.

More information

Domain Name System E-mail WWW. Application Layer. Mahalingam Ramkumar Mississippi State University, MS. September 15, 2014.

Domain Name System E-mail WWW. Application Layer. Mahalingam Ramkumar Mississippi State University, MS. September 15, 2014. Application Layer Mahalingam Mississippi State University, MS September 15, 2014 Outline 1 DNS Records DNS Components 2 Message Transfer Fetching Emails 3 Applications We will focus on 3 applications DNS

More information