Refer to the exhibit: A senior network architect has created the configuration above. You are implementing the setup in Building A and C. The actual fiber distance between the building locations is…

Question

Exhibit

Options

• AReplace the 25GR optics with 10SR
• BReplace the 25GR optics with 25LR
• CReplace the 25GR optics with 10LR
• DReplace the 25GR optics with 25SR

• A
  5% (2)
• B
  10% (4)
• C
  19% (8)
• D
  67% (28)

Explanation

Option D is correct because OM4 is a multimode fiber (MMF), and multimode fiber requires Short Range (SR) optics-not Long Range (LR) optics, which are designed for single-mode fiber (SMF). The CX 6300 VSF stack links operate at 25G, so the speed tier must remain 25G to support the 8 planned stack connections. Replacing the 25GR optics with 25SR gives you the correct fiber-type compatibility (multimode) at the correct speed (25G), and 25SR transceivers on OM4 are rated to handle the 200m span.

Why the distractors fail:

• A (10SR): SR is correct for OM4, but dropping to 10G unnecessarily halves throughput and mismatches the CX 6300 25G VSF stack port design.
• B (25LR): Speed is right (25G), but LR is engineered for single-mode fiber-using it on OM4 multimode will cause signal issues or link failure.
• C (10LR): Doubly wrong-wrong speed (10G) and wrong fiber category (LR for SMF, not OM4 MMF).

Memory tip: Link the letters to fiber type-SR = Short Range = "Same Room/building, multimode", LR = Long Range = "Laser-grade single-mode." When you see OM1–OM5 (the "O" = Optical multimode), always pair it with SR. When you see OS1/OS2 (single-mode), pair with LR.

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