ANS-C01 Network Design Practice Question
A company is using AWS Direct Connect to connect its on-premises data center to AWS. The company has a single hosted virtual interface (VIF) with a private VIF to a VPC. The network team notices that traffic from on-premises to AWS is asymmetric—some packets go through the Direct Connect while others use a VPN backup. The team wants all traffic to use Direct Connect when available. What should they do?
⚠ Common exam trap
A common mix-up: candidates assume AS_PATH prepending or removing the VPN is the solution, but the key is understanding that BGP's longest prefix match overrides all other path selection attributes, making prefix specificity the most reliable way to enforce traffic flow.
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
✓
Advertise more specific prefixes (e.g., /24) over Direct Connect and less specific (e.g., /16) over VPN.
BGP route selection prefers more specific prefixes (longest prefix match) over less specific ones. By advertising a more specific prefix (e.g., /24) over Direct Connect and a less specific prefix (e.g., /16) over the VPN, the on-premises router will prefer the Direct Connect path for the more specific route, ensuring all traffic uses Direct Connect when available. This leverages BGP's prefix-length-based path selection without requiring removal of the VPN backup.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Disable AS_PATH prepending on the Direct Connect BGP session.
Why it's wrong here
Disabling prepending could make on-premises routes less preferred, not more.
- ✗
Convert the private VIF to a public VIF.
Why it's wrong here
Changing VIF type does not address route preference.
- ✗
Remove the VPN connection to force all traffic through Direct Connect.
Why it's wrong here
Removing the VPN eliminates backup, which is not desired.
- ✓
Advertise more specific prefixes (e.g., /24) over Direct Connect and less specific (e.g., /16) over VPN.
Why this is correct
Correct: More specific BGP routes are preferred, so Direct Connect will be used when available.
Quick reference
Asymmetric Encryption Algorithm Comparison
| Algorithm | Key Exchange | Signatures | Equivalent Security Key | Notes |
|---|---|---|---|---|
| RSA-3072 | Yes | Yes | 128-bit | Widely deployed; slow for bulk data |
| ECDSA P-256 | No | Yes | 128-bit | Fast signatures; standard TLS certs |
| ECDH / ECDHE | Yes | No | 128-bit | Perfect forward secrecy in TLS 1.3 |
| DH / DHE | Yes | No | 128-bit (3072-bit key) | Replaced by ECDHE in modern TLS |
| Ed25519 | No | Yes | ~128-bit | SSH keys, modern PKI |
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.