CCNP Practice Question: Examine the following configuration snippet:…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  The OSPF hello interval is changed to 20 seconds, and the dead interval is changed to 80 seconds, maintaining the default 4:1 ratio.

  Why this is correct

  The OSPF configuration in the scenario explicitly sets the hello interval to 20 seconds and the dead interval to 80 seconds, which preserves OSPF's default dead-to-hello ratio of 4:1 (80/20 = 4). Because both neighbors are configured with these same values, the OSPF dead interval timer remains consistent, and adjacency formation occurs normally. This matches the requirement that neighbors must agree on timer values, not that a strict 4:1 ratio is mandated.

• ✗

  The OSPF hello interval is changed to 20 seconds, but the dead interval remains at the default of 40 seconds.

  Why it's wrong here

  This option incorrectly claims the dead interval stays at the default 40 seconds after the hello interval is changed to 20 seconds. In the given configuration, the dead interval is explicitly overridden to 80 seconds, so the final value is not 40. Even if the dead interval were 20 seconds (a 1:1 ratio) or 40 seconds (2:1), OSPF would still permit adjacency provided both sides advertise identical timers, but that is not what the configuration does.

• ✗

  The OSPF hello interval is changed to 20 seconds, and the dead interval is automatically set to 60 seconds.

  Why it's wrong here

  This option asserts that the dead interval is automatically recalculated to 60 seconds when the hello interval is set to 20 seconds. OSPF does not dynamically derive the dead interval from the hello interval; the dead interval is an independent timer that must be manually configured. In the scenario, the dead interval is explicitly set to 80 seconds, not auto-computed to 60, so this choice misstates both the configuration and OSPF behavior.

• ✗

  This configuration will cause OSPF adjacency failure because the dead interval must be exactly 4 times the hello interval.

  Why it's wrong here

  This option incorrectly predicts an adjacency failure because it assumes OSPF mandates a dead interval of exactly four times the hello interval. In reality, OSPF only requires routers on the same link to have matching hello and dead intervals; the 4:1 ratio is merely the default, not a protocol constraint. Since the configuration sets both timers to 20 and 80 seconds, the timers agree across the link, so adjacency forms successfully.