Câu 9: GSNA: GIAC Systems and Network Auditor

You work as a Network Administrator for XYZ CORP. The company has a Linux-based network. The company needs to provide secure network access. You have configured a firewall to prevent certain ports and applications from forwarding the packets to the company's intranet. What does a firewall check to prevent these ports and applications from forwarding the packets to the intranet?

1. A. The network layer headers and the session layer port numbers
2. B. The application layer port numbers and the transport layer headers
3. C. The transport layer port numbers and the application layer headers — đáp án hiện tại
4. D. The presentation layer headers and the session layer port numbers