ANS-C01 Network Implementation Practice Question
A network engineer is troubleshooting high latency on a Direct Connect connection. The engineer notices that the BGP session is flapping intermittently. The connection is a 1 Gbps dedicated connection with a single private VIF. The router configuration uses default BGP timers. What is the most likely cause of the flapping?
⚠ Common exam trap
Watch out — candidates often confuse BGP session flapping with configuration errors (like authentication or MED) rather than recognizing that transient packet loss is the most common cause of hold timer expiration on a single physical link.
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
✓
The link experiences occasional packet loss causing BGP hold timer expiration.
B is correct because the BGP hold timer (default 90 seconds) expires when the link experiences intermittent packet loss, causing the BGP session to flap. This is a common issue on Direct Connect when the underlying physical link has transient errors or congestion, leading to missed keepalive messages and session resets.
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 MTU size is set to 9001 (jumbo frames) on the Direct Connect interface.
Why it's wrong here
Jumbo frames do not cause BGP flapping; they affect packet fragmentation.
- ✓
The link experiences occasional packet loss causing BGP hold timer expiration.
Why this is correct
Packet loss can cause keepalive messages to be lost, leading to hold timer expiry and BGP session reset.
- ✗
The BGP authentication key is mismatched between the customer router and AWS.
Why it's wrong here
Incorrect authentication would cause the session to never establish or drop immediately, not flap.
- ✗
The Multi-Exit Discriminator (MED) value is set too high on the customer router.
Why it's wrong here
MED affects route preference, not session stability.
Go deeper
Related to this question
About these practice questions
One of 1,621 original ANS-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This ANS-C01 practice question is part of Courseiva's free Amazon Web Services 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 ANS-C01 exam.