ANS-C01 Question 188
Select 2You are designing a hybrid cloud architecture for a company that has an on-premises data center connected to AWS through a Direct Connect connection. The on-premises routers use BGP (Border Gateway Protocol) to dynamically advertise routes. In the AWS environment, you are using a Virtual Private Gateway (VGW) to connect the Direct Connect connection to your Amazon VPC. Which of the following routing configurations in your VPC is required to ensure proper routing of traffic between the VPC and the on-premises network?
- A
Enable route propagation on the VPC route table associated with the subnets where instances need access to the on-premises network.
- B
Manually add static routes in the VPC route table for all on-premises subnets.
- C
Configure BGP on the Virtual Private Gateway (VGW) to dynamically exchange routes with the on-premises routers.
- D
Create a NAT Gateway in the VPC to allow communication with the on-premises network.
- E
Ensure that the on-premises routers advertise their networks and accept routes from the VGW.
Show answer and explanation
Correct answers: A, E
Explanation
To ensure proper routing between the on-premises network and the VPC, route propagation must be enabled on the VPC route table so that the routes learned via BGP from the Virtual Private Gateway (VGW) are automatically added. Additionally, the on-premises routers need to advertise their networks to AWS and accept routes from the VGW for bidirectional traffic flow. This eliminates the need for manual route entries and ensures dynamic routing using BGP.
- A. Correct.
Correct: Enabling route propagation ensures that the routes learned via BGP through the Virtual Private Gateway (VGW) are automatically added to the VPC route table.
- B. Incorrect.
Incorrect: Manually adding static routes is unnecessary in this case because route propagation via BGP can dynamically handle the routes, reducing operational overhead.
- C. Incorrect.
Incorrect: You cannot configure BGP directly on the VGW. BGP is configured on the Direct Connect connection and the on-premises routers, while the VGW only facilitates route propagation.
- D. Incorrect.
Incorrect: A NAT Gateway is used to enable outbound internet access from private subnets and is not relevant for communication with the on-premises network.
- E. Correct.
Correct: For proper routing, the on-premises routers must advertise their networks to AWS and accept routes from the VGW via the BGP session over the Direct Connect connection.