ANS-C01 Network Design Practice Question
A solutions architect needs to design a VPC with both IPv4 and IPv6 support. The VPC will have public and private subnets. Resources in private subnets need outbound IPv6 access to the internet. Which combination of resources should be used?
⚠ Common exam trap
AWS often tests the misconception that a NAT gateway can handle IPv6 traffic, but NAT gateways are IPv4-only; the trap here is confusing the IPv4 outbound solution (NAT gateway) with the IPv6 outbound solution (egress-only internet gateway), or assuming an internet gateway can be used in private subnets with route restrictions.
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
✓
Internet gateway for public subnets and egress-only internet gateway for private subnets
An egress-only internet gateway (EIGW) is the AWS-managed service designed specifically to provide outbound-only IPv6 access from private subnets to the internet, while an internet gateway (IGW) handles both inbound and outbound IPv4/IPv6 traffic for public subnets. Unlike a NAT gateway, which only supports IPv4, the EIGW works with IPv6 and prevents any inbound IPv6 connections from the internet, meeting the requirement for outbound-only IPv6 access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Internet gateway for public subnets and VPC gateway endpoints for private subnets
Why it's wrong here
Gateway endpoints are for S3 and DynamoDB, not general internet access.
- ✗
Internet gateway for public subnets and NAT gateway for private subnets
Why it's wrong here
NAT gateway does not support IPv6.
- ✗
Internet gateway for both public and private subnets using route tables
Why it's wrong here
Private subnets would be accessible from internet.
- ✓
Internet gateway for public subnets and egress-only internet gateway for private subnets
Why this is correct
Egress-only internet gateway provides IPv6 outbound access for private subnets.
Visual reference
Go deeper
Related to this question
About these practice questions
This ANS-C01 question is part of Courseiva's 1,621-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. 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.