A proxy firewall filter works at –

2022

A proxy firewall filter works at –

  1. A.

    Physical layer

  2. B.

    Data link layer

  3. C.

    Network layer

  4. D.

    Application layer

Attempted by 78 students.

Show answer & explanation

Correct answer: D

Unlike traditional packet filters that only look at IP addresses or ports, a proxy firewall operates at the Application Layer (Layer 7).

  • How it works: It acts as an intermediary (proxy) between an internal user and the external server. It establishes a connection with the source and a separate connection with the destination.

  • Deep Packet Inspection (DPI): Because it operates at the application level, it can understand specific protocols (like HTTP, FTP, or SMTP). It doesn't just see "a packet"; it sees "a request to download a file" or "an email containing a virus," allowing it to filter content based on specific application rules.

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