Transcript B101 coursework assignment 2x

THE DOMAIN NAME SYSTEM
AS AN ADDRESS DIRECTORY
FOR THE WORLDWIDE WEB.
1
THE INTRODUCTION
•
Domain name system is a database system that translates a computer’s
full domain name into an IP address . On a network , it is much faster
and easier to locate and connect to computers on a network by their
host names rather than their IP addresses. (Knowledge, 2005 – 2010)
2
THE SIZE OF DOMAIN NAME SYSTEM
•
The domain name system practically doesn’t have a specific size. The
size is normally specifies by the subdomain and the domain of a
website which is enquired from a resolver. For example,
www.example.com belongs to the top –level domain (.com). For
example: the label example specifies a subdomain of the domain (.com),
and www is a subdomain of example(.com). Possibly in most cases, the
size of the domain name may not exceed 253 characters in its external
dotted-label specification. (Domain Name System,2011).
•
The DNS resolver is a software which request an IP address for a host
in the DNS hierarchy and completes the request from the host over the
internet.(Domain Name System, n.d.).
3
DOMAIN NAME SYSTEM COMPONENTS
•
The DNS consists of three main components which are the
•
Namespace,
•
Name server
•
Resolver
• The namespace establishes the syntactical rules for creating and
structuring legal DNS names.
• The “Name server” implements the “Globally Distributed Database”.
• The Resolver is the software which understands how to formulate a DNS
query and is built into practically every internet-capable application.
4
DOMAIN NAME SYSTEM COMPONENTS
•
The second key component of the DNS is a globally connected network
of “name servers”. Each zone has a primary or master name server,
which is the authoritative source for the zone’s resource records. The
primary name server is the only server that can be updated by means
of local administrative activity . Secondary or slave name servers hold
replicated copies of the primary server’s data in order to provide
redundancy and reduce the primary server’s load.
•
The namespace is similar to the inverted hierarchy with a null named “
“ at the top. The nodes of the root nodes are the Top Level
Domains(TLDs) like .com,.net,.org,.gov,.mil and the country code TLDs
including UP,.UK,.ca Node names are known as labels, can be as many
as 63 characters long, with upper-and lower case alphabetical letters,
and lower-case letters are treated equivalently.
5
DOMAIN NAME SYSTEM COMPONENTS
•
The namespace has the top level domains and the labels which are 63 characters
long with upper and lower cases. (Domain Namespace, 2012)
•
The second key component is the globally connected networks of name servers.
The name servers is the first place of search for resources for every zone.(
Nameservers,2010 – 2020)
•
The DNS resolver is responsible for initializing and sequencing queries that are
ultimately lead to a full resolution of resource sought for. ( DNS Resolver, 2011 )
6
DOMAIN NAME SYSTEM COMPONENTS
•
The third component of the DNS is the “resolver”. The resolver is a
piece of software that is implemented in the IP stack of every
destination point. When a host is configured, manually or through
DHCP, it’s assigned at least one default name server along with its IP
address and subnet mask. This name server is the first place that the
host looks in order to resolve a domain name into an IP address.(DNS
COMPONENTS,2006).
• The client-side of the DNS is called DNS resolver. It is responsible for
initializing and sequencing the queries that ultimately lead to a full
resolution of the resource sought. For example, translation of a domain
name into an iP address. (Domain Name System, 2011)
7
8
DIAGRAM OF THE DOMAIN NAME SYSTEM
•
The diagram above consists of the Root level domain which are the .net,
.edu, .org, .gov, .com.
•
The Top Level domain consists like “.com “ consists of the second
level domain which is ntchosting .
•
The second level domain (ntchosting) consists of the subdomain of
ntchosting which are the consulting , www, blog, forum.
•
Consulting is part of the subdomain of ntchosting which also consists
of the WWW and the ftp . . (ENCYCLOPEDIA:DNS,2002– 2010)
9
10
DESCRIPTION OF DIAGRAM ABOVE
•
The image above show the structure of the public protected network
and the private network which includes the internet, public routing ,
managed VPS servers, private routing system and the services.
•
The protected public network consists of the internet and the public
routing. The public routing consists of the firewall and the public
switch.
•
The Managed VPS servers consists of the customers. The private
routing consists of the private switch.
11
DESCRIPTION OF DIAGRAM ABOVE
•
The services also consists of the software updates server, the DNS
server, the monitoring /metrics server and the Backup server.
• DNS requests are guaranteed to be lighting fast and place zero load
on your virtual Private Server..( HARDWARE, 2000 – 2011)
• The DNS server makes it possible for client computers to use names
rather than numeric IP addresses. ( DNS server, 2012 )
• Virtual Private Server(VPS) is a term used by Internet Hosting Server
and is referred to as a Virtual Machine. The term is used to described a
virtual machine as a real computer or physical computer which is
dedicated to computer service and also runs as a server machine. (
Virtual Private Server, 2011 )
12
FUNCTIONS OF THE DOMAIN NAME SYSTEM
•
One of the functions of the Domain Name System is the DNS
caching. With DNS caching, a caching server obtains information from
another (a zone master) in response to a host query and then saves it.
DNS caching is the function that makes the modern internet usable.
DNS caching is nothing more than a local machine hold onto the DNS
information from external zones for a given amount of time. (Negus,
2004).
13
HOW LEGISLATION AFFECTS THE OPERATION OF
THE DOMAIN NAME SYSTEM
• “London could get its own internet domain names” is the issue . This
issue talks about London and Partners applying for what is described
as a generic top-level domain (gTLD). It also talks about ICANN
creating several hundred new gTLD’s in the new process of assigning
London with new domain names. London & Partners is currently
consulting with organizations including the boroughs, commercial
organizations and community groups to determine the benefits of
having a London internet domain name. (NEWS LONDON, 2011)
14
LIMITATIONS TO THE OPERATION OF THE
DOMAIN NAME SYSTEM
•
An instance of the limitation to the operation of the Domain Name
System is from an article from the IBM website about the multilingual
domain name race. It cites that it is high time that it became necessary
to support multilingual domain names. In this article, the President of
BizWonk Inc. who is Suzanne Topping delves into the details of this
thorny issues, including several of the noteworthy proposals for solving
this Dilemma, as well as the realities of implementing a solution. .(The
multilingual domain name race,2000)
15
REFERENCES
1. Knowledge Base(2005 – 2010). Retrieved from university information Technology
Services: http://kb.iu.edu/data/adns.html
2. Domain Name System, 2011. Retrieved from
http://en.wikipedia.org/wiki/Domain_Name_System
3. DNS-Domain Name System(n.d). Retrieved from About.Com
Wireless/Networking:
http://compnetworking.about.com/cs/domainnamesystem/g/bldef_dns.htm
4 . DNS COMPONENTS.(2006). Retrieved from ACCUWEBHOSTING.COM :
http://www.accuwebhosting.com/Articles/DNS_COMPONENTS.html
5. Encyclopedia:DNS(2002 – 2010). Retrieved from ntchosting:
http://www.ntchosting.com/dns terminology.html( Posted By Alvin on Saturday,
April 29, 2006)
16
REFERENCES
6. Hardware(2000 – 2011). Retrieved from HOSTCUBE:
http://hostcube.com/what-you-get/hardware/
7. Negus(2004).Linux Troubleshoot Bible,Indianapolis: Wiley Publishing. Inc. (
page number 314 ).
8. News London(2011).Retrieved from BBC mobile:http://www.bbc.co.uk/news/ukengland-london-15034876
9. Suzanne Topping(2000).The multilingual domain name race. Retrieved from
http://www.ibm.com/developerworks/library/u-domains.html
10. Virtual Private Server (2011).Retrieved from Wikipedia
:http://en.wikipedia.org/wiki/Virtual_private_server .(This page was last modified
on 24 December 2011 at 02:07.)
11. Domain Resolvers (2011 ). Retrieved from Wikipedia
:http://en.wikipedia.org/wiki/DNS_resolver#DNS_resolvers
17
REFERENCES
12. DNS Server Role (2012) . Retrieved from Windows Server TechCenter :
http://technet.microsoft.com/en-us/library/cc753635%28WS.10%29.aspx
13. DNS Resolver ( 2011). Retrieved from Wikipedia :
http://en.wikipedia.org/wiki/DNS_resolver#DNS_resolvers
14. Domain Namespace ( 2012). Retrieved from wikipedia
http://en.wikipedia.org/wiki/Domain_Name_System
15. Nameservers( 2010 – 2020). Retrieved from ACCUWEBHOSTING.COM:
http://www.accuwebhosting.com/Articles/DNS_COMPONENTS.html
18
END OF PRESENTATION
THE END
19