The correct answer is to apply BGP community tags from Direct Connect to set a higher local preference, which ensures traffic uses the Direct Connect link when available and fails over to the VPN backup. This works because AWS Direct Connect assigns specific BGP community tags that, when received by the Transit Gateway, allow you to manipulate the local preference attribute on the Direct Connect routes, making them more preferred than the VPN routes. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of BGP path selection and how AWS uses community tags to influence routing without modifying on-premises configurations. A common trap is confusing local preference with AS_PATH prepending or MED, which control inbound traffic, not outbound preference from the AWS side. Remember the memory tip: "Local loves outbound, AS_PATH and MED are for inbound," so when you need AWS to prefer one path over another, think local preference via community tags.
ANS-C01 Network Management and Operations Practice Question
This ANS-C01 practice question tests your understanding of network management and operations. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company uses AWS Direct Connect and VPN as backup. They have a Transit Gateway with multiple VPC attachments. The network engineer wants to ensure that traffic uses Direct Connect when available and fails over to VPN. Which configuration should be applied?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Apply BGP community tags from Direct Connect to set a higher local preference.
Option D is correct because BGP communities from AWS allow setting local preference to prefer Direct Connect routes over VPN. Option A is wrong because AS_PATH prepending is for inbound route selection. Option B is wrong because MED is for inbound selection. Option C is wrong because BFD detects failure but does not control preference.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Set a higher MED value on the VPN BGP advertisements.
Why it's wrong here
MED is used for inbound route selection.
✗
Prepend AS_PATH on the VPN BGP advertisements to make them less preferred.
Why it's wrong here
AS_PATH prepending affects inbound routes, not outbound.
✓
Apply BGP community tags from Direct Connect to set a higher local preference.
Why this is correct
AWS uses BGP community tags to influence local preference.
Related concept
Static NAT maps one inside address to one outside address.
✗
Configure BFD on both Direct Connect and VPN interfaces.
Why it's wrong here
BFD detects failures but does not control route preference.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related ANS-C01 NAT questions on configuration and troubleshooting.
Network Management and Operations — This question tests Network Management and Operations — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Apply BGP community tags from Direct Connect to set a higher local preference. — Option D is correct because BGP communities from AWS allow setting local preference to prefer Direct Connect routes over VPN. Option A is wrong because AS_PATH prepending is for inbound route selection. Option B is wrong because MED is for inbound selection. Option C is wrong because BFD detects failure but does not control preference.
What should I do if I get this ANS-C01 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related ANS-C01 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.