mediumMultiple Choice
300-410 Statements about BFD echo mode is true? Practice Question
Which of the following statements about BFD echo mode is true?
⚠ Common exam trap
300-410 often tests the misconception that echo mode increases remote router load — the opposite is true; the trap is confusing echo mode with asynchronous control-packet mode.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Echo mode allows the local router to detect failures without requiring the remote router to send BFD control packets.
In BFD echo mode, the local router sends echo packets that the remote router simply loops back (typically by forwarding to the same interface) without processing them as BFD control packets. This lets the local system detect forwarding-path failures on its own, without requiring the remote router to run BFD control-packet logic or maintain BFD state. The remote device only needs to forward the echo packets, which reduces its BFD processing burden.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Echo mode increases the load on the remote router because it must process echo packets.
Why it's wrong here
Echo packets are looped back by the forwarding path of the remote system without involving its control plane, so remote CPU load stays low. Increased remote processing load occurs with control packets, which the remote router must receive and process.
- ✗
Echo mode is disabled by default and must be explicitly enabled.
Why it's wrong here
Echo mode is enabled by default on Cisco platforms; it is disabled per interface with no bfd echo, so explicit enablement is not required. The statement would hold for features that ship inactive, such as BFD itself on some interfaces.
- ✗
Echo mode uses the same timer values as the BFD control packets.
Why it's wrong here
Echo mode uses independently negotiated echo timers, not the control packet timer values; echo packets are transmitted at the echo interval. Sharing control timers applies to asynchronous control packets, which is a separate mechanism from echo function timers.
- ✓
Echo mode allows the local router to detect failures without requiring the remote router to send BFD control packets.
Why this is correct
Echo mode decouples failure detection from the peer's control-plane: the local router sends echo packets that the remote system loops back, so loss of return traffic triggers detection even if the neighbour stops transmitting BFD control packets.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 300-410 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 300-410 exam.