Due to the impact of the rapid popularization of Internet and e-commerce, most organizations and enterprises take great effort to protect their information systems against malicious attacks and invasions. The firewall is the most familiar method among relevant technologies for Internet security. However, the firewall systems in use today are either application software or utilities running on the personal computers or network nodes. It is very inconvenient to implement and manage the conventional firewalls. In order to make the management and construction of them easier without disrupting the existing network topology, we implement an embedded and distributed firewall system to safeguard the Internet. In this way, we combine the functions of the firewall and a central security policy server into an embedded system, which can be realized as a network interface card.