Abstract: This paper presents a detailed study of firewall technologies which are commonly used for network security. A firewall cannot handle all the destructive threats which are coming from unauthorized networks. Therefore, to develop a secured network different types of firewall technologies are used. Lot of researches have been done considering technologies of firewalls. The main purpose of this paper is to apply firewall capacity along with other firewall technologies such as packet filtering, network address translation, virtual private network and proxy services in order to prevent unauthorized accesses. Due to lack of many researches, related to firewall capacity and firewall technologies together. The research group focuses to build a more protected network by combining both firewall capacity and firewall technologies. The experiment results show the proposed idea good enough to build a secured network.