Network Security

senegaleseloudNetworking and Communications

Nov 21, 2013 (4 years and 1 month ago)

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Seyhan Aydin 200098


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Network Security


1.

Introduction


As the internet boom continues, we see the exponential expansion of networks and the
need for people to transmit more and more data electronically.

However, due to the
relative ease that the internet presents the user with
to transmit such data, the possibilities
for other parties to intercept, modify or prevent the sending of such data is a real threat.
Therefore the aspect of network security in an IP
1

based word needs to be carefully
examined and assessed. This report loo
ks at the most common exploitations,
vulnerabilities and preventative methods that are employed (and should be employed) by
individual and corporate networks alike.


2.

Network Fundamentals


The concept of connecting more than one PC together has been wi
th u
s for at least forty
years, but in recent times, the method of IP or
peer to peer

networks has shown to be the
most effective for our everyday method of communication, though of course this is still a
vastly improving
area.


But what makes a good network?

According to
BC Soh
and

S Young
2

the fundamentals of
a good reliable network are
integrity

and
secrecy.



Maintaining the integrity of a network means that data transmitted across a network will
be free of modifications by either an unauthorised user, or
incorrect functioning of
hardware or software. For example, a file being sent across a network will lose its
integrity if there is some kind of interruption in transmission causing the file to be
modified in someway. The security of a network refers to the

confidentiality of data
being maintained as it is being sent across a network, thus preventing unauthorised
users
for reading or modifying someone else’s data.


2.1

Why attack?


Why
is

the security of a network so important? By not securing data and/or enfor
cing
policies upon network use by individual means that computers on a network are open to
abuse to unauthorised persons. The ‘attack’ may be non intentional


i.e. a user scans a
range of IP addresses for a response if a response is received then that use
r may
investigate further, possibly downloading, modifying distributing otherwise confidential
data. Some methods of attack, namely
Denial of Service
(DoS) require the use of many
computers in order to prevent the normal day to day service of perhaps, a se
rver by
bombarding it with many millions of requests for data, thus preventing it from providing
a service to legitimate users.





1

Internet Protocol

2

BC Soh and S Young:
“Network System and World Wide Web Security”
Computer Communications
20(1998) 1431
-
1436

Seyhan Aydin 200098


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Other attacks may be to gain information off other users
, in order to gain knowledge or
even for nuisance purposes such as spa
mming. Other attacks are simply for some people
to show their expertise off to other users.


3.

Methods of attack



The methods of attack upon networks most commonl
y encountered are as follows:




Denial of Service



Viruses, Trojans, Worms



Software Flaws



Buffe
r Overflows



3.1

Denial of Service