AWS Certified SysOps Administrator – Associate (legacy) — Question 923

The networking team has created a VPC in an AWS account. The application team has asked for access to resources in another VPC in the same AWS account.
The SysOps Administrator has created the VPC peering connection between both the accounts, but the resources in one VPC cannot communicate with the resources in the other VPC.
What could be causing this issue?

Answer options

• A. One of the VPCs is not sized correctly for peering.
• B. There is no public subnet in one of the VPCs.
• C. The route tables have not been updated.
• D. One VPC has disabled the peering flag.

Correct answer: C

Explanation

After establishing a VPC peering connection, you must manually update the route tables associated with the subnets in both VPCs to direct traffic to the peer VPC via the peering connection. Without these route table updates, resources cannot locate or communicate with each other. Other factors, such as the absence of a public subnet or non-existent 'peering flags', do not cause this routing failure.