The firewall is developed in recent years to protect a computer network security technology, is currently the most widely used of a network security technology. The firewall is one or a group of access control strategy for the implementation of the system, which can be software, hardware or a combination of hardware and software, its purpose is to provide security protection for the network. Firewalls often in the internal network and external networks, can monitor, control and changes in internal and external networks of the mobile communication network; control external access to internal computer protected environment, and to determine the time to visit, competence, the types of service And quality, check the spread of internal information, avoid the outflow of confidential information, to resist external invasion and prevent the leakage of internal information purposes. This paper presents a firewall configuration in the importance of network security, explain the firewall rule set is a firewall product safety is an important measure. Key words: network security firewall configuration