UNDERSTAND NETWORK SERVICE
1) MUHAMMAD HISYAMUDDIN BIN DERAMAN
2) MUHAMAD AIMAN BIN SHAMSUDIN
3) SITI RAUDHAH BT RAMYA @ ABD RAHIM
4) NOOR AZIZAH BINTI ABDUL AZIZ
5) MOHD KHAIRUL AIMAN BIN OTHMAN
(12QEP12F1001)
(12DEP11F1019)
(12DEP11F1017)
(12DEP11F1013)
(12DEP11F1038)
Network Service
Definion & function :
• Basic network computing environment. It is generally
provided in one or more servers to provide shared
resources to client computers.
• To ensure security and user friendly operation. It
helps LAN (Local Area Network) run smoothly and
efficiently
Figure 1 :Network Services
Common Network Services
•
•
•
•
•
•
•
Domain Name System (DNS)
Dynamic Host Configuration Protocol (DHCP)
Authentication Server
Directory Services
E-mail
Printing
File Sharing
Domain Name System (DNS)
• A system that stores information about host names and
domain names on a network such as the Internet.
• Most importantly, it provides an IP address for each
host name and a list of mail exchange servers that
receives mail for each domain.
• DNS plays an important role because the hardware
requires Internet IP addresses to perform routing and
men use the host name and domain name for example
the Uniform Resource Locator (URL) and e-mail
address.
How DNS works
The domain name consists of two or more parts
(labels) separated by dots (●). Labels on the right is
the top-level domain (for example top-level domain
to www.wikipedia.org is org). Each label to the left to
determine subdivision or subdomain (for example,
wikipedia.org is a subdomain of the org and
subdomains to wikipedia.org is www.wikipedia.org).
www.wikipedia.org
subdomain (wikipedia.org) top-level domain (org)
• DNS consists of a hierarchical set of DNS servers. Each domain has one or
more authentic DNS server (DNS authoritative serves) that publish
information about that domain. Authentic hierarchy of DNS servers have a
match with the domain hierarchy.
• An commonly used analogy to explain DNS is that it works as a phone
book for the Internet by translating friendly computer hostnames into IP
addresses man. For example, the domain name www.example.com
translates to the addresses 192.0.43.10 (IPv4) and 2620:0:2 d0: 200 :: 10
(IPv6).
• DNS will distribute the responsibility for providing domain names and
mapping of names to IP addresses by setting the authoritative name
servers for each domain name. Therefore the authoritative server
responsible for a particular domain, which may set other authoritative
name servers for their sub-domains.
• DNS also specifies the technical functionality of this database service. It is
defined as DNS protocol. Detailed specification of data structures and
communication exchanges used in DNS is part of the Internet Protocol
Suite.
Figure 2 : DNS Network Services
•http://www.youtube.com/watch?v=JtOlK4Kbx2w
Ping Command
• Ping is a computer network administration utility used to test
whether a particular host is reachable across an Internet Protocol
(IP) network and to measure the round-trip time for packets sent
from the local host to a destination computer, including the local
host's own interfaces.
• Ping operates by sending Internet Control Message Protocol (ICMP)
echo request packets to the target host and waits for an ICMP
response.
Browser
• network browser is a tool used to browse a computer network.
• An example of this is My Network Places (or Network
Neighborhood in earlier versions of Microsoft Windows).
• An actual program called Network Browser is offered in Mac OS 9.
Nslookup
• nslookup is a computer program used in Windows
and Unix to query Domain Name System (DNS)
servers to find DNS details, including IP addressed
of a particular computer, MX records for a domain
and the NS server of a domain.
• The name nslookup means "name server lookup".
• The most common version of the program is
included as part of the BIND package.
IMPLIMENT DNS IN A LAN
• Corporate LANs use network services such as
DNS to give names to IP and MAC addresses
and DHCP to ensure that everyone on the
network has a valid IP address.
• For example, names like “nm.lan” is better
than numbers like “210.121.67.18”,
2.5.4 RELATIONSHIP BETWEEN WEB
CLIENTS AND SERVERS
Web client??
is actually your browser. It is the browser on you PC/Mac that
makes the requests to the remote server. A PC/Mac that uses
a web (Client) browser is referred to as a Client Machine.
Web Server??
is basically a PC that is designed to accept requests from
remote computers and send on the information requested.
• A web server is a computer program that delivers (serves)
content, such as web pages, using the Hypertext Transfer
Protocol (HTTP), over the World Wide Web.
• Refer to the computer or virtual machine running the
program.
• The primary function of a web server is to deliver web pages
to clients.
• A client, commonly a web browser or web crawler, initiates
communication by making a request for a specific resource
using HTTP and the server responds with the content of that
resource, or an error message if unable to do so
2.5.5 RELATIONSHIP BETWEEN FTP CLIENTS
AND SERVERS
What is FTP Client?
personal computer or a mobile device that is running
application software that is able to communicate with and
retrieve files from a FTP server.
What is FTP Server?
high powered device that holds the files and other
information that is required to satisfy the requests coming
from clients over the internet/intranet. FTP server
continuously runs and listens for incoming FTP requests.
• File Transfer Protocol (FTP) is a standard network protocol
used to copy a file from one host to another over a TCP/IPbased network, such as the Internet.
• FTP is used with user-based password authentication or with
anonymous user access.
• Example :A client makes a connection to the server on TCP
port 21. This connection, called the control connection,
remains open for the duration of the session, with a second
connection, called the data connection, on port 20 opened as
required to transfer file data.
• The control connection is used to send administrative data
(i.e., commands, identification, passwords).
• The server responds on the control connection with three
digit status codes in ASCII with an optional text message, for
example "200" (or "200 OK.") means that the last command
was successful.
• The numbers represent the code number and the optional
text represent
Types E-mail protocols
E-mail protocols in clients and servers
have 3 types :
• SMTP
• POP3
• IMAP4
SMTP
• Simple mail transfer protocol (SMTP) is an
internet standard for electronic mail (e-mail)
transmission across internet protocol (IP)
networks.
• SMTP was first defined in RFC821 and last
updated by RFC5321 which includes the
extended SMTP (ESMTP) additions .
• SMTP is specified for outgoing mail transport
and uses transmission control protocol (TCP)
port 25.
• Electronic mail servers and other mail transfer
agents used SMTP to send and receive mail
message.
• User–level client mail use SMTP for sending
messages to mail server for relaying.
• For receiving message, client applications
usually use :
i. Post office protocol (POP)
ii. Internet message access protocol (IMAP)
iii. Proprietary system ( such as Microsoft
Exchange or Locus Notes/Domino)
POP3
• Post office protocol (POP) is an application –
layer internet standard protocol used by local
e-mail clients to retrieve e-mail from a remote
server over a TCP/IP connection.
• POP and IMAP are two most prevalent
Internet standard protocols for e-mail
retrieval.
• POP3 is a being current standard
• POP3 is used for most mail clients such as :
i. Gmail
ii. Yahoo
IMAP4
• The internet message access protocols (IMAP) is one of the
two most prevalent internet standard protocols for email
retrieval, the other being the post office protocols (POP).
• IMAP4 permits manipulation of remote message folders
called "mailboxes", in a way that is functionally equivalent to
local mailboxes.
• IMAP4 also provides the capability for an offline client to
resynchronize with the server (see also [IMAP-DISC]).
• IMAP4 includes operations for creating, deleting, and
renaming mailboxes, checking for new messages,
permanently removing messages, setting and clearing flags.
Organizational
Networks are typically managed by the organizations that own them.
Private enterprise networks may use a combination of intranets and
extranets. They may also provide network access to the Internet, which
has no single owner and permits virtually unlimited global connectivity.
Intranets and extranet
• Intranets and extranets are parts or extensions of a computer
network, usually a LAN.
• An intranet is a set of networks that are under the control of a
single administrative entity. The intranet uses the IP protocol and
IP-based tools such as web browsers and file transfer applications.
The administrative entity limits use of the intranet to its authorized
users. Most commonly, an intranet is the internal network of an
organization. A large intranet will typically have at least one web
server to provide users with organizational information.
An extranet is a network that is also under the administrative
control of a single organization, but supports a limited connection
to a specific external network. For example, an organization may
provide access to some aspects of its intranet to share data with its
business partners or customers. These other entities are not
necessarily trusted from a security standpoint. Network connection
to an extranet is often, but not always, implemented via WAN
technology.
Internetwork
An internetwork is the connection of multiple computer
networks via a common routing technology using routers.
Internet
• The Internet is the largest example of an internetwork. It is a global
system of interconnected governmental, academic, corporate,
public, and private computer networks. It is based on the
networking technologies of the Internet Protocol Suite. It is the
successor of the Advanced Research Projects Agency
Network (ARPANET) developed by DARPA of the United States
Department of Defense. The Internet is also the communications
backbone underlying the World Wide Web (WWW).
• Participants in the Internet use a diverse array of methods of
several hundred documented, and often standardized, protocols
compatible with the Internet Protocol Suite and an addressing
system (IP addresses) administered by the Internet Assigned
Numbers Authority and address registries. Service providers and
large enterprises exchange information about the reachability of
their address spaces through the Border Gateway Protocol (BGP),
forming a redundant worldwide mesh of transmission paths.
THANK YOU
ANY QUESTION???