Which OSPF design consideration, with regards to simplicity and address preservation, must be considered when connecting two Layer 3 switches directly using 10 GBASE-T cabling and formatting an OSPF…

Question

Options

• AMesh groups must be included in the design
• BThe OSPF Hello and Dead timers must be tuned to detect failures as quickly as possible
• CThe OSPF network type must be set to point-to-multipoint
• DAn OSPF neighbor adjacency formed over loopback interfaces must be placed in Area 0
• EThe OSPF network type must be set to point-to-point

• A
  6% (3)
• B
  4% (2)
• C
  2% (1)
• D
  12% (6)
• E
  77% (40)

Explanation

Setting the OSPF network type to point-to-point (E) is correct because a direct cable between two Layer 3 switches is, by definition, a two-device link. Point-to-point eliminates the unnecessary DR/BDR election process (simplicity) and allows the use of /31 subnets or unnumbered interfaces instead of /30s (address preservation) - both goals the question explicitly targets.

Why the distractors fail:

• A (Mesh groups): Mesh groups control OSPF flooding in NBMA environments like legacy Frame Relay - irrelevant to a direct Ethernet link.
• B (Hello/Dead timer tuning): Addresses fast failure detection, not simplicity or IP address conservation.
• C (Point-to-multipoint): Designed for hub-and-spoke or partial-mesh topologies; on a direct link it generates unnecessary /32 host routes, wasting resources and adding complexity.
• D (Loopback in Area 0): A valid OSPF practice for certain designs, but unrelated to the link type or address preservation concern described here.

Memory tip: When you see a direct cable between exactly two devices, think "two devices = point-to-point." P2P = no DR/BDR (simpler) + /31 or unnumbered (fewer IPs). If there are more than two potential neighbors on the segment, then you'd consider broadcast or non-broadcast types.

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