Learning Goals

• Define the purpose of a firewall and explain its role in network and application security.
• Differentiate packet-filtering, stateful inspection, and proxy-based firewall approaches.
• Analyze firewall rule sets to determine whether specific application traffic should be allowed or denied.
• Explain how firewalls interact with services such as HTTP, FTP, TELNET, and email in practical deployments.
• Evaluate the strengths and limitations of firewalls in defending against unauthorized access, malware, and protocol misuse.