Question

    Which firewall type inspects packets at all layers of the

    OSI model to ensure complete protection?
    A Packet Filtering Firewall Correct Answer Incorrect Answer
    B Stateful Firewall Correct Answer Incorrect Answer
    C Proxy Firewall Correct Answer Incorrect Answer
    D Next-Generation Firewall (NGFW) Correct Answer Incorrect Answer
    E Network Address Translation (NAT) Firewall Correct Answer Incorrect Answer

    Solution

    A Next-Generation Firewall (NGFW) inspects packets at all layers of the OSI model, from the Physical Layer to the Application Layer. Unlike traditional firewalls, NGFWs integrate advanced features like deep packet inspection (DPI), intrusion prevention systems (IPS), and application awareness. They can identify malicious payloads in applications, enforce advanced security policies, and protect against sophisticated cyber threats like zero-day attacks. Why Other Options Are Incorrect:

    •  Packet Filtering Firewall: This operates only at the Network Layer (Layer 3) and filters packets based on source/destination IP and ports but does not inspect payloads.
    •  Stateful Firewall: While stateful firewalls track connections and operate at Layer 4, they lack deep packet inspection capabilities.
    •  Proxy Firewall: Proxy firewalls inspect traffic at the Application Layer (Layer 7) but do not analyze data from all OSI layers.
    • NAT Firewall: NAT modifies IP addresses to enable private network access to external networks. It is not a security-focused firewall.

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