SCS-C02 Question 226
Single answerYour organization has set up a Site-to-Site VPN between your on-premises data center and an Amazon VPC. After the VPN connection is established, you notice intermittent connectivity issues. Upon investigation, you determine that the issue is caused by mismatched configuration settings between the on-premises VPN device and the AWS VPN. Which configuration setting mismatch is most likely to cause such issues?
- A
The encryption algorithm used for the VPN tunnel
- B
The amount of bandwidth available on the on-premises internet connection
- C
The AWS Security Group rules attached to the VPN gateway
- D
The IAM role permissions associated with the VPN connection
Show answer and explanation
Correct answer: A
Explanation
For a Site-to-Site VPN to function correctly, both the AWS VPN and the on-premises VPN device must use matching configurations, including the encryption algorithm, shared key, and other parameters. A mismatch in the encryption algorithm is a common cause of intermittent connectivity or outright tunnel failures. By ensuring both sides have consistent configurations, the VPN connection can operate reliably.
- A. Correct.
A mismatch in the encryption algorithm (e.g., AES-128 vs. AES-256) between the AWS VPN and the on-premises VPN device can cause intermittent connectivity or failure to establish the VPN tunnel.
- B. Incorrect.
While bandwidth limitations can affect network throughput, they do not typically cause intermittent connectivity or VPN tunnel establishment issues.
- C. Incorrect.
AWS Security Groups do not apply to VPN gateways; they apply to EC2 instances or other services within the VPC. Therefore, they are not relevant in this scenario.
- D. Incorrect.
IAM role permissions are not relevant to the operational properties of a Site-to-Site VPN. They control access to AWS resources but do not impact VPN connectivity.