BN206 System Administration: Comprehensive Analysis of Networking

This report provides a comprehensive overview of computer networking, starting with the basic definitions of computer networks, nodes, and data transfer rates. It explores the client/server model, different types of networks including LAN, WAN, and MAN, and various network topologies such as ring, star, and bus. The report delves into internet connections, discussing internet backbones, ISPs, and technologies like phone modems, DSL, and cable modems. It also covers packet switching, open systems, the OSI Reference Model, and network protocols like TCP/IP, UDP, SMTP, FTP, and HTTP. Furthermore, the report addresses network security with firewalls and explores network addresses, the Domain Name System (DNS), and top-level domains. This resource is valuable for understanding the fundamental concepts of computer networking and system administration, particularly within the context of the BN206 course. Desklib provides access to similar solved assignments and past papers for students.

Networking
Computer network A collection of
computing devices that are connected in
various ways in order to communicate and
share resources
Usually, the connections between computers
in a network are made using physical wires or
cables
However, some connections are wireless,
using radio waves or infrared signals
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Networking
The generic term node or host refers to any
device on a network
Data transfer rate The speed with which
data is moved from one place on a network to
another
Data transfer rate is a key issue in computer
networks
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NetworkingComputer networks have opened up an entire
frontier in the world of computing called the
client/server model
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Figure 15.1 Client/Server interaction

Networking
File server A computer that stores and
manages files for multiple users on a network
Web server A computer dedicated to
responding to requests (from the browser
client) for web pages
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Types of Networks
Local-area network (LAN) A network that
connects a relatively small number of
machines in a relatively close geographical
area
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Types of Networks
Various configurations, called topologies,
have been used to administer LANs
Ring topology A configuration that connects all
nodes in a closed loop on which messages travel in
one direction
Star topology A configuration that centers
around one node to which all others are connected
and through which all messages are sent
Bus topology All nodes are connected to a
single communication line that carries messages
in both directions
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Types of Networks
A bus technology called Ethernet has become
the industry standard for local-area networks
Figure 15.2 Various network topologies
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Types of Networks
Wide-area network (WAN) A network that
connects two or more local-area networks
over a potentially large geographic distance
Often one particular node on a LAN is set up to
serve as a gateway to handle all communication
going between that LAN and other networks
Communication between networks is called
internetworking
The Internet, as we know it today, is essentially
the ultimate wide-area network, spanning the
entire globe
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Types of Networks
Metropolitan-area network (MAN) The
communication infrastructures that have
been developed in and around large cities
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So, who owns the Internet?
Well, nobody does. No single person or
company owns the Internet or even controls it
entirely. As a wide-area network, it is made
up of many smaller networks. These smaller
networks are often owned and managed by a
person or organization. The Internet, then, is
really defined by how connections can be
made between these networks.
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Figure 15.1 Local-area networks connected across a distance to
create a wide-area network

Internet Connections
Internet backbone A set of high-speed
networks that carry Internet traffic
These networks are provided by companies
such as AT&T, GTE, and IBM
Internet service provider (ISP) A
company that provides other companies or
individuals with access to the Internet
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