What is the primary function of a firewall?

What is the primary function of a firewall?

• A. To route packets between networks.
• B. To monitor performance metrics of servers.
• C. To provide wireless access to users.
• D. To control traffic between networks using rules and stateful inspection to enforce security.

Answer: (D)

The primary function of a firewall is to control traffic between networks by enforcing a security policy with rules and stateful inspection. It sits at the network boundary and examines each packet, deciding to allow or block based on criteria like source and destination IP addresses, ports, and protocols. Stateful inspection adds another layer by tracking the state of active connections, so only packets that are part of legitimate, established communications (or their required responses) are permitted. This combination helps prevent unauthorized access and a range of threats while still letting legitimate traffic flow. The other options describe different network roles: routing packets is done by a router, monitoring performance metrics is a server-management task, and providing wireless access is the job of an access point.

The primary function of a firewall is to control traffic between networks by enforcing a security policy with rules and stateful inspection. It sits at the network boundary and examines each packet, deciding to allow or block based on criteria like source and destination IP addresses, ports, and protocols. Stateful inspection adds another layer by tracking the state of active connections, so only packets that are part of legitimate, established communications (or their required responses) are permitted. This combination helps prevent unauthorized access and a range of threats while still letting legitimate traffic flow. The other options describe different network roles: routing packets is done by a router, monitoring performance metrics is a server-management task, and providing wireless access is the job of an access point.