Troubleshooting Direct Connect Packet Drops: BGP Status and Physical Metrics
A network engineer is troubleshooting intermittent connectivity issues between an on-premises data center and a VPC over a Direct Connect connection. The engineer reviews the CloudWatch metrics for the virtual interface and sees an increase in 'ConnectionReset' and 'PacketDropRate'. Which TWO actions should the engineer take to resolve the issue? (Choose TWO.)
Quick Answer
The answer is to check BGP metrics and physical layer metrics such as light levels and signal strength. These two actions directly address the root causes of intermittent Direct Connect packet drops: BGP route flapping, which triggers ConnectionReset events as sessions bounce, and degraded physical optics, which increases the PacketDropRate due to signal loss or errors. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your ability to isolate issues between Layer 1 physical health and Layer 3 BGP stability, a common trap being to jump to MTU or VPN fixes that don’t affect Direct Connect. Remember that Direct Connect packet drops and BGP status are tightly linked—if the light is low, the BGP session will flap. A useful memory tip is “Light first, BGP next”—always verify physical metrics before touching routing protocols.
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
✓
Check the BGP session status and metrics on the virtual interface
Options C and E are correct. Checking the BGP session status and metrics on the virtual interface helps identify if there are BGP-related issues such as route flapping or session drops that could cause connectivity problems. Checking physical layer metrics like light levels and signal strength can reveal underlying physical issues with the Direct Connect connection. Option A is incorrect because adding BGP peers does not address the symptoms of ConnectionReset and PacketDropRate. Option B is incorrect because increasing MTU could actually increase drop rates if the underlying physical layer has issues. Option D is incorrect because the VPN connection is not directly related to Direct Connect and increasing its bandwidth would not resolve issues with the Direct Connect connection.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Add additional BGP peers to the Direct Connect connection
Why it's wrong here
Does not address drops.
- ✗
Increase the MTU on the virtual interface to 1500
Why it's wrong here
MTU increase may cause fragmentation issues.
- ✓
Check the BGP session status and metrics on the virtual interface
Why this is correct
BGP issues can cause connection resets.
- ✗
Increase the bandwidth of the VPN connection as a backup
Why it's wrong here
Not relevant.
- ✓
Check the physical layer metrics such as light levels and signal strength
Why this is correct
Physical layer issues cause drops.
Visual reference
Go deeper
Related to this question
About these practice questions
Courseiva writes every ANS-C01 question from scratch — 1,621 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on ANS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network engineer is troubleshooting intermittent connectivity issues between an on-premises data center and AWS over a Direct Connect connection. The engineer notices that BGP sessions are flapping. What should the engineer check first?
easy- A.Configure route propagation in the VPC route tables.
- ✓ B.Verify BGP timers and ensure they match on both sides.
- C.Check the virtual interface (VIF) status in the AWS console.
- D.Increase the MTU on the Direct Connect link.
Why B: Mismatched BGP timers (e.g., hold timer, keepalive interval) are a common cause of BGP session flapping on AWS Direct Connect. Option A is incorrect because route propagation in VPC route tables affects route advertisement, not BGP session stability. Option C is incorrect because while VIF status indicates the link is up or down, flapping is often due to configuration mismatches like timers rather than VIF status alone. Option D is incorrect because increasing MTU can address packet fragmentation but does not directly prevent BGP flapping.
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.