Network security is an important task that must be seriously considered when designing a network. Network security is defined as the policies and procedures followed by a network administrator to protect the network devices from threats and simultaneously, the unauthorized users must be prevented from accessing the network. Network firewalls are devices or systems that control the flow of traffic between networks employing different security postures. The network traffic flow is controlled according to a firewall policy. The filtering decision is based on a firewall policy defined by network administrator. For each type of network traffic, there are one or more different rules.