You created a VPC peering connection but instances in VPC A cannot reach instances in VPC B. What is the most likely cause?

medium📝 Debug Q14 of 15

AWS - VPC Fundamentals

AInstances need public IP addresses to communicate over peering

BThe VPC peering connection is automatically rejected after creation

CRoute tables in VPC A or VPC B do not have routes to the peer VPC's CIDR block

DSecurity groups do not allow internet traffic

Step-by-Step Solution

Solution:

Step 1: Check common VPC peering issues
Communication fails often because route tables lack routes to the peer VPC's CIDR block.
Step 2: Evaluate other options
The VPC peering connection is automatically rejected after creation is false; peering is not auto-rejected. Instances need public IP addresses to communicate over peering is wrong; public IPs are not needed. Security groups do not allow internet traffic is unrelated to peering communication.
Final Answer:
Route tables in VPC A or VPC B do not have routes to the peer VPC's CIDR block -> Option C
Quick Check:
Missing routes cause peering communication failure [OK]

Quick Trick: Check route tables first when peering fails [OK]

Common Mistakes:

MISTAKES

Master "VPC Fundamentals" in AWS

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

More AWS Quizzes