GIAC Exam GISF Topic 2 Question 4 Discussion

A firewall is a combination of hardware and software, used to provide security to a network. It isused to protect an internal network or intranet against unauthorized access from the Internet orother outside networks. It restricts inbound and outbound access and can analyze all trafficbetween an internal network and the Internet. Users can configure a firewall to pass or blockpackets from specific IP addresses and ports. Which of the following tools works as a firewall forthe Linux 2.4 kernel?