Direct Connect Encryption: MACsec vs IPsec for Compliance
A financial services company uses AWS Direct Connect to connect its data center to multiple VPCs via a transit gateway. They need to meet PCI DSS compliance requirements by encrypting all traffic between the data center and AWS. What solution meets this requirement with the least operational overhead?
Quick Answer
The answer is enabling MACsec on the Direct Connect connection because it provides encryption at Layer 2, securing all traffic between the data center and AWS without the operational overhead of managing VPN tunnels or additional protocols. MACsec operates directly on the physical link, ensuring PCI DSS compliance by encrypting the entire data stream transparently to higher-layer applications. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of when to choose MACsec over IPsec for Direct Connect encryption, with the common trap being to default to IPsec due to its familiarity, even though it adds complexity and tunnel management overhead. A key memory tip is to think of MACsec as the “set-and-forget” encryption at the wire level, while IPsec requires routing and policy configuration—so for least overhead, always pick MACsec when the Direct Connect port supports it.
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
✓
Enable MACsec on the Direct Connect connection.
MACsec (Option A) is the correct solution because it provides encryption at Layer 2 directly on the Direct Connect connection, ensuring all traffic is encrypted with minimal overhead and no additional configuration. This meets PCI DSS requirements with the least operational overhead. Option B (TLS) only encrypts application-level traffic, not all traffic. Option C (private VIFs) does not encrypt traffic by default. Option D (IPsec VPN over Direct Connect) adds complexity and operational overhead compared to MACsec.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Enable MACsec on the Direct Connect connection.
Why this is correct
MACsec provides Layer 2 encryption with minimal overhead.
- ✗
Use TLS for all application traffic between data center and VPC.
Why it's wrong here
TLS only encrypts application traffic, not all IP traffic.
- ✗
Use private VIFs without additional encryption.
Why it's wrong here
Private VIFs are not encrypted.
- ✗
Create an IPsec VPN tunnel over the Direct Connect VIF to encrypt traffic.
Why it's wrong here
IPsec adds operational overhead and reduces throughput.
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
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Variation 1. A company is using AWS Direct Connect to connect to its VPC. The network team wants to encrypt all traffic between the on-premises data center and the VPC. Which solution provides encryption?
easy- A.Enable MACsec on the Direct Connect connection.
- ✓ B.Use an IPsec VPN over the Direct Connect virtual interface.
- C.Use AWS Client VPN to connect on-premises to VPC.
- D.Enable encryption on the Direct Connect virtual interface.
Why B: IPsec VPN over Direct Connect provides encryption for all traffic between on-premises and VPC. Direct Connect itself does not encrypt traffic. MACsec is supported on dedicated Direct Connect connections and provides Layer 2 encryption, but it only encrypts the link between the customer device and AWS, not end-to-end traffic. AWS Client VPN is for individual clients, not site-to-site. Direct Connect virtual interfaces do not support native encryption. Therefore, the correct solution is to use an IPsec VPN over the Direct Connect virtual interface.
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.