Report on the use of Firewalls in Network Security

Introduction:
A firewall is defined as a piece of software or hardware used to enforce network security policies by monitoring both internal and external network traffic ensuring that unwanted access or data is prohibited. Most of the modern firewalls that are used today are software based solutions however some exist as hardware solution with embedded software logic. Many authors on firewall technologies are of the opinion that the firewall acts as a bridge between a private internal network and external networks such as the internet. The primary functions of a firewall are as follows: * It limits the entry points to a network * Prevents malicious software or individuals from entering the private network * It limits the exit points from the network
Since all traffic leaving and entering the internal network the firewall is considered to be the single most important tool to be used to protect a network. It allows the network administrators to know exactly the state of the network security.
Currently, there are different types of firewall implementation. These ranges from dedicated routers and switches with embedded software to a single dedicated host computer with appropriate software. A firewall does not exist as a single piece of hardware solution. In fact, it is the software that is hosted by the hardware that is capable of carrying out the appropriate analyses of the network traffic to ensure that the correct policies are enforced. To achieve this, a firewall normally utilizes one or more of the following technologies: 1. Packet – Filtering 2. Proxy

Types of firewalls

Generally, a firewall is categorized by the type of technology that it uses. The two main types of firewalls are: Packet – Filtering Firewalls and Proxy Firewalls.

Packet-Filtering Firewalls: Packet