DESIGN AND IMPLEMENTATION OF AN ENHANCED FIREWALL SYSTEM

1.1 Introduction

A Firewall is a device that block unauthorized access to organization’s local area network (LAN) a firewall can reside on the administrative computer (the server) that acts as the LAN’s gateway to the internet or it can be a dedicated computer placed between the LAN and the internet, so that the network is never in direct contact with the internet. It is also a perimeter security device that filters packets that traversing across the boundaries of a secured network. The filtering decision is based on a policy defined by the network administrator. A firewall policy is an ordered list of rules. A firewall rule defines an action, typically accept or reject, for the set of packets matching its criteria. Most of firewalls filter traffic according to first-match semantics. When a packet p arrives, it is compared against the rules in a top-down fashion until a matching rule is found and the process is repeated for the following packet. All policies admit a hidden match-all default rule at the end. Therefore, when a packet does not match a rule in the policy, then the default action is followed.

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.

1.2 Background of Study

The term “firewall” originally meant a wall to confine a fire or potential fire within a building. Later uses refer to similar structures, such as the metal sheet separating the engine compartment of a vehicle or aircraft from the passenger compartment. Talal Alkharobi (2002) stated that firewall technology emerged in the late 1980s when the internet was a fairly new technology in terms of its global use and connectivity. The predecessors to firewalls for network security were the routers used in the late 1980s to separate networks from one another. The view of the internet as a relatively small community of compatible users who valued openness for sharing and collaboration was ended by a number of major internet security breaches which occurred in the late 1980s.

Before the term "firewall" was applied to network technology a "firewall" was used in building design and mechanical engineering to designate a wall or partition composed of flame-resistant materials put in place to protect more flammable structural components from catching fire or spreading flames, either accidentally in the case of an unexpected fire, or where flame is usually present and needs to be isolated. Many building codes require fire-rated materials in human-inhabited areas. Firewalls protect vulnerable assets (such as spaces that might contain people) and prevent destructive events from spreading too quickly.

According to Zhang et al., (2007) it is possible to use any field of IP, UDP, or TCP headers. In most firewalls, the default rule is deny-all, however a permit-all default rule is also possible. A rule is given with a set of fields, where each field can have an atomic value or a range of values. A firewall is a part of a computer system or network that is designed to block unauthorized access while permitting authorized communications. It is a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all (in and out) computer traffic between different security domains based upon a set rules and other criteria. Firewalls can be implemented in either hardware or software, or a combination of both. Firewalls are frequently used to prevent unauthorized internet users from accessing private networks connected to the internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

A firewall is a dedicated appliance, or software running on a computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules. It is a software or hardware that is normally placed between a protected network and an unprotected network and acts like a gate to protect assets to ensure that nothing private goes out and nothing malicious comes in.

Kenneth Ingham and Stephanie forest (2004) stated that a firewall’s basic task is to regulate some of the flow of traffic between computer networks of different trust levels. Typical examples are the internet which is a zone with no trust and an internal network which is a zone of higher trust. A zone with an intermediate trust level, situated between the internet and a trusted internal network, is often referred to as a “perimeter network” or demilitarized zone (DMZ).

A firewall’s function within a network is similar to physical firewalls with fire doors in building construction. In the former case, it is used to prevent network intrusion to the private network. In the latter case, it is intended to contain and delay structural fire from spreading to adjacent structures. Without proper configuration, a firewall can often become worthless. Standard security practices dictate a default deny firewall rule set, in which the only network connection which are allowed are the ones that have been explicitly allowed unfortunately, such a configuration requires detailed understanding of the network applications and endpoint required for the organization’s day to day operation. Many businesses lack such understanding, and therefore implement a “default allow” rule set, in which all traffic is allowed unless it has been specifically blocked. This configuration makes inadvertent network connections and system compromise much more likely.

1.3 Statement of Problem

Investigation revealed that our world has become increasingly digitalized and there seems to be a computer revolution which has inflicted almost every aspect of human endeavor. As a result, there are risks and threat associated with the computer system especially computers on network hence the need for developing a robust firewall frame work for computer system.

The design and development of such a system will help in making the networked computer system less vulnerable to criminal activities of hackers, crackers and other malicious software developers. Protecting online computer users from these nefarious activities in the form of theft of money and other negotiable financial instruments, theft of trade secrets, internet frauds, data leakage and eavesdropping illegally into other people’s information is of high importance. As a result of these highlighted problems, it becomes imperative to develop a firewall system that protects computer system from cyber attack, bearing in mind the need for an effective information management system.

1.4 Aim and Objectives of the Study

The aim of the study is to design and implement an Enhanced Firewall System. In achieving this aim, the following specific objectives were laid out as follows to develop an application software that will:

1. Assess the risks, threat and vulnerability analysis of information management in information security;
2. Protect computer system against the attack of viruses and other malicious software;
3. Facilitate an uninterrupted flow in the exchange of data, image and sound amongst network users;
4. Protect computer users from the activities of hackers and crackers;
5. Enhance durability of the computer system; and
6. Promote a critical awareness of the nature, role and limitation of the various techniques and tools associated with firewall system.

1.5 Significance of Study

This research the design and implementation of an Enhanced Network Firewall System is quite significant in the sense that it helps in providing a protective sheath for network computer system against cyber attack from different categories of cyber criminals.

It is also significant in the sense that it helps in promoting a digitally secured society thereby enhancing free flow of data interchange between millions of online computer user. It should be noted however that no system (including a properly configured firewall system) is absolutely secure. Firewall systems are often very large and complex software and hardware configurations and it is unwise to rely completely on this system as they are usually built from untrusted components.

This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.

1.6 Scope of Study

The scope of the research is focused on the Design and Implementation of an Enhanced Firewall System.

1.7 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Establishment Policies: Establishment policies posed a serious limitation as most staffs are not ready to release information needed for this project work. There were lots of information needed from the staffs of this institution to enhance the study which took them time to release or they did not release at all for security purposes, hence the scope was reduced.
3. Research material: availability of research material is a major setback to the scope of the study.
4. Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
5. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).

1.8 Definition of Terms

Firewall: In computer security it is a device that block unauthorized access to organization’s local area network (LAN) a firewall can reside on the administrative computer (the server) that acts as the LAN’s gateway to the internet or it can be a dedicated computer placed between the LAN and the internet, so that the network is never in direct contact with the internet.

Virtual Private Network: a network set up for use by a limited number of individuals, such as employees of a company, operating over a large area. The network typically uses encryption to keep information secure.