The answer is to configure a static route in the VPC route table pointing to the virtual private gateway with a more specific prefix for the on-premises network. This works because AWS route tables use longest prefix match, so a static route with a more specific CIDR (e.g., /24) will override any less specific routes learned via BGP from other customer gateways, forcing traffic through the designated CGW. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of how to manipulate routing within a VPN CloudHub architecture, where multiple CGWs connect to a single VGW. A common trap is assuming BGP metrics alone can deterministically force traffic, but BGP attributes like AS path prepending are only advisory and can be overridden by static routes. Remember the memory tip: "Specificity beats BGP"—a more specific static route always wins over dynamic BGP routes in AWS.
ANS-C01 Network Implementation Practice Question
This ANS-C01 practice question tests your understanding of network implementation. 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 is troubleshooting connectivity issues between an on-premises network and a VPC connected via AWS VPN CloudHub. The on-premises network uses multiple customer gateways (CGWs) connected to a single virtual private gateway (VGW). The company wants to ensure that all traffic from the VPC to on-premises is routed through a specific CGW. Which configuration should be used?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure a static route in the VPC route table pointing to the VGW with a more specific prefix for the on-premises network
Option A is correct because using a more specific prefix in the static route forces traffic through that CGW. Option B is wrong because BGP metrics influence path selection but are not deterministic. Option C is wrong because VPN tunnel options affect encryption, not routing. Option D is wrong because multiple CGWs per VGW is possible with CloudHub.
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.
✗
Adjust the BGP local preference on the preferred CGW to a higher value
Why it's wrong here
Local preference is an AS-path attribute, not directly set on CGW.
✗
Remove the other CGWs from the VGW
Why it's wrong here
This would remove redundancy.
✗
Modify the VPN tunnel option to prefer the specific tunnel
Why it's wrong here
Tunnel options do not control routing.
✓
Configure a static route in the VPC route table pointing to the VGW with a more specific prefix for the on-premises network
Static NAT maps one inside address to one outside address.
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 Implementation — This question tests Network Implementation — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Configure a static route in the VPC route table pointing to the VGW with a more specific prefix for the on-premises network — Option A is correct because using a more specific prefix in the static route forces traffic through that CGW. Option B is wrong because BGP metrics influence path selection but are not deterministic. Option C is wrong because VPN tunnel options affect encryption, not routing. Option D is wrong because multiple CGWs per VGW is possible with CloudHub.
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.