The correct answer involves three actions: prepending the AS path on the Direct Connect BGP advertisement for the 10.0.1.0/24 prefix, setting a higher local preference on the VPN route for that same prefix, and ensuring the more specific 10.0.1.0/24 route is advertised over the VPN. This works because BGP route preference prioritizes the most specific prefix match—so the /24 wins over the /8—and local preference is checked before AS path length, making the VPN route more attractive for the targeted subnet. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of BGP route manipulation for VPN and Direct Connect, where you must control traffic flow without breaking connectivity. A common trap is thinking you can simply disable route propagation on the VPN, but that would remove the desired path entirely. Memory tip: think “specificity first, then local preference, then AS path prepend” to remember the BGP decision order for hybrid connectivity.
ANS-C01 Network Implementation Practice Question
This ANS-C01 practice question tests your understanding of network implementation. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 has a VPC with a CIDR of 10.0.0.0/16 and needs to connect to an on-premises network using AWS Direct Connect and a Site-to-Site VPN. The on-premises network advertises 10.0.0.0/8 over BGP. The company wants to ensure that traffic to the VPC's specific subnet 10.0.1.0/24 is routed via the VPN, while all other traffic to 10.0.0.0/8 uses Direct Connect. Which THREE actions should the network engineer take?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set a higher BGP local preference on the VPN routes compared to Direct Connect routes for the same prefix.
Option A, Option B, and Option C are correct. A more specific prefix (10.0.1.0/24) is preferred over 10.0.0.0/8. Setting a higher local preference on the VPN route for 10.0.1.0/24 also ensures it is preferred. Additionally, using an AS path prepend on Direct Connect for the specific prefix can make it less preferred. Option D is wrong because disabling propagation on VPN would remove the route. Option E is wrong because the VPN should be used for the specific subnet, not disabled.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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 BGP local preference on the VPN routes compared to Direct Connect routes for the same prefix.
Delete the VPN connection and rely solely on Direct Connect.
Why it's wrong here
The requirement is to use VPN for the specific subnet.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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 block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related ANS-C01 subnetting questions on CIDR, address ranges, and subnet selection.
Network Implementation — This question tests Network Implementation — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Set a higher BGP local preference on the VPN routes compared to Direct Connect routes for the same prefix. — Option A, Option B, and Option C are correct. A more specific prefix (10.0.1.0/24) is preferred over 10.0.0.0/8. Setting a higher local preference on the VPN route for 10.0.1.0/24 also ensures it is preferred. Additionally, using an AS path prepend on Direct Connect for the specific prefix can make it less preferred. Option D is wrong because disabling propagation on VPN would remove the route. Option E is wrong because the VPN should be used for the specific subnet, not disabled.
What should I do if I get this ANS-C01 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related ANS-C01 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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.