Network security: ensuring maximum protection through firewall

Thesis Overview

<p> </p><ol><li><strong>&nbsp;Introduction</strong></li></ol><p>Computer<br>network is the engineering discipline concerned with communication between<br>computer system and devices. The purposes of networking are exchange of data<br>and resources sharing. With network, large volume of data can be exchanged<br>through both short and long-range connections. Likewise computer resources such<br>as hardware (printers, scanner etc.) and software can be remotely shared among<br>network hosts.</p><p>&nbsp; &nbsp; With increase reliance on computer<br>network, calls for serious monitoring of the traffic in and out of the system<br>network. Attackeron the internet<br>could break into the network and do harm in a number of ways; they can steal or<br>damage important data, damage individuals computer or their entire network, and<br>use the internal network computer resources. Due to some of these security<br>threats, there was the need to build a defensive mechanism that ensures that<br>attackers and their likes are not allowed into the network. Firewalls are<br>designed to stop unwanted or suspected traffics from flowing into the internal<br>network. Sets of rules are applied to control the type of networking traffic<br>flowing in and out of the system. This would ensure that attackers have no<br>access to the internal network.</p><p>&nbsp; &nbsp; &nbsp; This thesis is<br>organized in four chapters. Chapter 2 provides theoretical background<br>information about firewalls, roles, controls and their impact in network<br>security; a comprehensive<br>literature review on how network traffic can be monitored in order to prevent<br>an unauthorized access to internal network. Chapter 3, we proposed and<br>developed an improved software based solution that allows all the inbound and<br>outbound traffic to pass through the firewall which, in turn determines which<br>traffic should be allowed in or out of the network using object-oriented<br>methodology. Chapter 4, Firewall security system was implementation using<br>software-based solution. The use of Java programming language and the concept<br>of xml and html programming were considered in order to achieve our objectives.</p><p><strong>1.1</strong>&nbsp;<strong>Statement of Problem</strong></p><p>The problem to be solved is the<br>problem of organizations network. What can firms do to protect their network<br>over potential threats against the “resources” they share on the network?</p><p><strong>1.2 Objectives</strong></p><ol><li>To developed a firewall system to<br>block unauthorized access to the network and prevent malicious attack which<br>could lead to data loss</li><li>To build a secured network, based on software<br>firewall to protect network resources and ensured the integrity and confidentiality<br>of information on the network are not compromised</li></ol><p><strong>1.3 Significance of the Study</strong></p><p>The significance of this study is to<br>show how a firewall could prevent attack and protect network resources which<br>will make harder for an attacker to penetrate into the system. The system will<br>be able to offer online services. The probability of exploring vulnerability<br>will be reduced to low risk and the system will be more stable</p><p><strong>Chapter 2: Literature<br>Review</strong></p><p><strong>2.0 Introduction</strong></p><p>This<br>chapter describes what firewalls can do for network security, types of network<br>attack. What firewall needs to control and protect and the impact of firewall<br>in organisation network and users. A review on how network traffic can be monitored in order to<br>prevent an unauthorized access to internal network.</p><p><strong>2.1 Theoretical Background</strong></p><p>Firewalls are usually the first component of<br>network security. They separate networks in different security levels, by<br>utilizing network access control policies. The major function of the firewall<br>is to protect the private network from non-legitimate traffic.</p><p>Firewalls are located between the Internet and<br>private network. They can monitor the outgoing and incoming traffic; also they<br>can prevent the harmful traffic and attacks from Internet. They also can stop<br>the non-legitimate outgoing traffic. If a computer from the local network is<br>attacked by an intruder and generates non-legitimate traffic, the firewall can<br>prevent and detect the computer. Firewall can detect such succeeded attack, so<br>it can be recovered.</p><p>A firewall is the most effective way to connect a<br>network to the Internet and still protect that network [1]. Firewalls create a<br>separation between public networks (Internet) and private networks by examining<br>the traffic according to the predefined policy, and allowing only legitimate<br>traffic to pass between the public and private network. They help implementing<br>a larger security policy that defines the services and access to be permitted.<br>It is an implementation of that policy in terms of a network configuration, one<br>or more host systems and routers, and other security measures such as advanced<br>authentication in place of static passwords.</p><p>A firewall system can be a router, a personal<br>computer, a host, or a collection of hosts and/or routers, set up specifically<br>to shield a site or subnet from protocols and services that can be abused from<br>hosts outside the subnet [2]. Firewalls<br>must be installed at the choke points to control network traffic and implement<br>network security policy of the organization. Firewalls achieve this by<br>examining the all incoming and outgoing network traffic according to the<br>predefined firewall policy. All network traffic must pass through the firewall,<br>which ensures that only permitted traffic are allowed through [3]. Firewalls<br>have some advantage and disadvantages they are summarized below.</p><p>Advantages:</p><p>• Firewalls can stop non-legitimate traffic<br>at first point,</p><p>• Firewalls can filter protocols and services<br>that are either not necessary or that cannot be adequately secured from<br>exploitation [4],</p><p>• A firewall can “hide” names of internal<br>systems and internal network schema, thereby revealing less information to<br>outside hosts [4],</p><p>• Firewalls can concentrate extended logging<br>of network traffic on one system.</p><p>Disadvantages:</p><p>• Firewalls utilize manually configured set<br>of rules to differentiate legitimate traffic from non-legitimate traffic,</p><p>• Once a static policy is defined, the<br>firewall can’t react to a network attack – nor can it initiate effective<br>counter-measures [4],</p><p>• Firewalls only examine network packets that<br>pass through them, do not examine network traffic between any two inside hosts,</p><p>• Most firewalls do not analyse the contents<br>of the data packets that make up network traffic,</p><p>• Firewall policies can vary in effectiveness, depending on the expertise of the security manager and the complexity of the network environment.</p> <br><p></p>