ANS-C01 Network Design Practice Question
A company has a VPC with a CIDR of 10.0.0.0/16 and needs to connect to two on-premises locations via AWS Direct Connect. Each Direct Connect connection uses a private VIF. The company wants to use BGP to exchange routes. The on-premises routers advertise the same prefix 10.0.0.0/8 for both connections. How should the network engineer configure the VPC route tables to ensure traffic is load balanced across both Direct Connect connections?
⚠ Common exam trap
Test-takers frequently assume AWS requires Transit Gateway or VPN overlay to achieve load balancing, but AWS natively supports ECMP across multiple Direct Connect private VIFs attached to the same VPC, as long as the BGP-advertised prefixes are identical and the routes are installed in the same route table.
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
✓
Allow BGP to install both routes; AWS will automatically load balance across them using ECMP.
AWS Direct Connect private VIFs support BGP route exchange, and when two separate connections advertise the same prefix (10.0.0.0/8), BGP installs both routes in the VPC route table. AWS automatically performs Equal-Cost Multi-Path (ECMP) routing across the two Direct Connect connections, load-balancing traffic without additional configuration. This behavior is inherent to how AWS handles multiple BGP-learned routes with identical prefixes and metrics.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Create a VPN connection over the Direct Connect and use BGP with different metrics.
Why it's wrong here
This is unnecessary and adds complexity.
- ✗
Create two separate route tables and associate each with half the subnets.
Why it's wrong here
This would not load balance traffic; each subnet would use only one connection.
- ✗
Use AWS Transit Gateway with equal cost multipath routing.
Why it's wrong here
Transit Gateway does not change ECMP behavior; Direct Connect still installs routes in the VPC route table.
- ✓
Allow BGP to install both routes; AWS will automatically load balance across them using ECMP.
Why this is correct
When identical routes are learned from two Direct Connect connections, AWS uses ECMP.
Visual reference
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.