What is the key benefit of Palo Alto Networks single-pass architecture (SPA) design?

Question

Options

• AIt requires only one processor to complete all the functions within the box.
• BIt allows the addition of new functions to existing hardware without affecting performance.
• CIt allows the addition of new devices to existing hardware without affecting performance.
• DIt decodes each network flow multiple times, therefore reducing throughput.

• A
  72% (13)
• B
  6% (1)
• C
  17% (3)
• D
  6% (1)

Explanation

Palo Alto Networks' Single-Pass Architecture (SPA) processes each packet once through all security functions - App-ID, User-ID, Content-ID, threat prevention, etc. - in a single scan, rather than handing the packet off to multiple inspection engines sequentially. This is why A is correct: all functions are completed in one unified pass by a single processing pipeline, dramatically reducing latency and CPU overhead compared to traditional multi-pass designs.

Why the distractors are wrong:

• B is a tempting distractor - SPA does support adding new security functions without rearchitecting the system, but the key benefit described is the single-pass processing model, not hardware extensibility.
• C confuses "functions" with "devices" - SPA is about how traffic is processed internally, not about adding external hardware to a cluster.
• D is the opposite of reality - SPA decodes each flow once, which increases throughput, not reduces it. Multi-pass architectures are what decode traffic multiple times.

Memory tip: Think of SPA like a single airport security line where one agent checks your ID, scans your bags, and clears you all at once - versus the old way where you'd wait in separate lines for each check. "One pass, one processor, one decision" captures the core idea.

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