N10-009 Question 180
Single answerA network administrator is upgrading a three-floor office building. The ISP demarcation point, edge router, and core firewall are located in a secured telecom room on the first floor. Each floor has its own closet for access switches that connect user workstations. The new switches are deeper than the old ones, and the model selected uses port-side intake airflow. In one floor closet, the rack is mounted with its front facing a wall, leaving only a few inches of clearance where the switch ports would be located. Which action is the BEST to ensure a proper installation and avoid operational issues?
- A
Install the access switch in the floor's IDF, but use a rack with sufficient depth and orient the switch so the port-side intake has adequate clearance for airflow and cable management
- B
Install the access switch in the building MDF instead, because all switching equipment should be centralized near the demarcation point
- C
Keep the shallow rack and mount the switch anyway, because port-side airflow only affects noise levels and not switch reliability
- D
Move the edge router from the MDF to the floor closet and place the access switch in the MDF so the rack depth is no longer a concern
Show answer and explanation
Correct answer: A
Explanation
The best answer is to keep the access switch in the IDF that serves the floor and correct the physical installation problem by using the proper rack size and preserving clearance for the switch's port-side intake. In structured cabling and enterprise network design, the MDF commonly serves as the central distribution point and houses the demarcation, backbone interconnections, and often core network/security devices. IDFs are used to distribute connectivity to local users on each floor or area. Physical installation details matter: rack dimensions must accommodate device depth, and airflow direction such as port-side exhaust or intake must align with room and rack layout so vents are not obstructed. These practices are consistent with common vendor installation guidance for switches and with structured cabling best practices such as those reflected in TIA-568/TIA-569 concepts for telecommunications spaces and pathways.
- A. Correct.
Correct. Access switches that serve end-user devices on a given floor are typically installed in that floor's IDF, while the MDF commonly houses core connectivity such as the demarc, edge router, firewall, and backbone interconnects. Because the replacement switch is deeper and uses port-side intake airflow, the installer must account for both rack depth and clearance at the port side so the switch can draw air properly and so patch cables are not crushed or bent excessively. Choosing an appropriately sized rack and proper orientation addresses the real installation constraints.
- B. Incorrect.
Incorrect. The MDF is not the best location for every switch simply because it is near the demarcation point. Centralizing all access switching there would defeat the purpose of floor-level IDFs and could require longer horizontal cabling runs, potentially exceeding structured cabling design goals. The scenario describes per-floor closets specifically intended for access-layer equipment.
- C. Incorrect.
Incorrect. Port-side intake is a critical installation consideration, not just a cosmetic or acoustic one. If the intake side is blocked by a wall or packed cabling, airflow is restricted, which can cause overheating, reduced hardware lifespan, thermal alarms, or shutdowns. This option reflects the common misconception that airflow direction is unimportant as long as the device powers on.
- D. Incorrect.
Incorrect. Moving the edge router to a floor closet is poor design in this scenario. The edge router belongs in the MDF near the ISP demarcation and core security infrastructure. Relocating it does not solve the underlying issue of improper rack sizing and inadequate clearance in the IDF, and it introduces unnecessary complexity and security concerns.