300-410 Practice Question: The default BFD multiplier (detection time…

Answer analysis

Option-by-option breakdown

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

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  1

  Why it's wrong here

  Cisco IOS-XE defaults the BFD multiplier to 3, not 1. A multiplier of 1 would make detection time equal to the control packet interval, which is far too aggressive for production links. It is tempting as the theoretical minimum, but the actual default is 3.

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  2

  Why it's wrong here

  Cisco IOS-XE defaults to a BFD multiplier of 3, so 2 would shorten detection and risk false positives unless explicitly configured. The multiplier is tempting because 2 appears in some vendor defaults, and it would be correct where faster failure detection is deliberately traded against stability.

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  3

  Why this is correct

  Cisco IOS-XE uses a default BFD detection multiplier of 3, meaning three consecutive missed control packets trigger a session-down event. Combined with the default 50 ms transmit interval, this yields a 150 ms detection time, satisfying the question's request for the default multiplier value.

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  4

  Why it's wrong here

  Cisco IOS-XE defaults the BFD multiplier to 3, not 4. The multiplier is applied to the negotiated transmit interval to derive detection time. It is tempting because 4 appears in some vendor documentation, but IOS-XE uses 3.