Is there anyway to see VPC site to site VPN connection proposal information

Greeting

Hi Gary,

Thanks for sharing your question. As an AWS Expert, your ability to drill down into technical details is impressive, and it’s great to see you looking for ways to gain deeper visibility into Site-to-Site VPN connection proposals. Your approach to securing connections without default options shows a level of care and expertise that really stands out. Let’s tackle this challenge and explore how to gain the insights you need. 🚀

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Clarifying the Issue

From what you’ve described, the crux of the issue lies in the limited visibility that CloudWatch logs provide when debugging VPN tunnel failures. While these logs confirm AWS evaluates the connection proposal, they don’t offer detailed information about the endpoints or specific configurations being negotiated. Without this data, pinpointing the root cause—especially for a custom, secure setup—can be frustrating. You’re on the right track, and I completely understand the need for granular details to ensure everything aligns perfectly. Let’s explore some advanced strategies to bridge this gap.

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Key Terms

• VPC Site-to-Site VPN: A managed AWS service enabling encrypted connections between AWS and on-premises networks or other AWS VPCs.
• CloudWatch Logs: A monitoring service capturing AWS activity, including VPN connection events.
• IKE (Internet Key Exchange): A protocol facilitating secure key exchange and connection proposals during VPN setup.
• VPN Tunnel Options: Configurations like encryption, hashing algorithms, pre-shared keys, and lifetimes that define VPN tunnel security.
• AWS Expert: A community-recognized designation for individuals with advanced AWS knowledge and contributions—a true badge of honor!

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The Solution (Our Recipe)

Steps at a Glance:

1. Enable detailed VPN logging in CloudWatch with extended log filters for IKE phases.
2. Use VPN Tunnel Diagnostics and AWS Config Rules for automated checks.
3. Request IKE negotiation debug logs from AWS Support.
4. Analyze on-premises peer device logs alongside AWS logs for discrepancies.
5. Cross-reference proposals using a temporary VPN with default parameters.
6. Simulate VPN configuration mismatches using a lab setup for deeper insights.

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Step-by-Step Guide:

1. Enable Detailed VPN Logging:
   • Ensure detailed logging is enabled for your VPN connection. Set up CloudWatch log filters to capture IKE negotiation details:

     aws ec2 modify-vpn-connection --vpn-connection-id vpn-12345678 \
       --options EnableCloudWatchLogs=true

   • For a targeted view, use CloudWatch Logs Insights to filter IKE-related events:

     fields @timestamp, @message
     | filter @message like /IKE/
     | sort @timestamp desc

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2. Utilize Diagnostic Tools:
   • Use the VPN Tunnel Diagnostics tool in the AWS Console to identify algorithm mismatches or endpoint issues.
   • Set up AWS Config Rules to monitor compliance with VPN best practices. For example, ensure tunnel lifetimes and encryption standards match your policies.

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3. Request IKE Debug Logs:
   • If the CloudWatch logs don’t provide enough detail, request IKE debug logs from AWS Support. These logs include the full proposal, with endpoint details and specific parameters under negotiation.

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4. Validate Peer Device Logs:
   • Analyze the logs from your on-premises or third-party device. Look for discrepancies in proposals, such as mismatched encryption algorithms or pre-shared keys. For example:

     Phase 1 proposal:
     - Encryption: AES-256
     - Hashing: SHA-256
     - Lifetime: 28800 seconds

   • Compare these parameters to the AWS VPN connection settings.

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5. Cross-Reference with a Default VPN Connection:
   • Create a temporary VPN connection using AWS default parameters. Compare the success of its IKE negotiations with your custom connection.

     aws ec2 create-vpn-connection --type ipsec.1 \
       --customer-gateway-id cgw-12345678 --vpn-gateway-id vgw-12345678

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6. Simulate Configuration Mismatches in a Lab Setup:
   • Use a test environment (e.g., AWS Lightsail or a local VM) to recreate your VPN setup. Test mismatched configurations deliberately to simulate failures. For instance, use an invalid pre-shared key or a mismatched algorithm to replicate errors, then compare logs.

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Closing Thoughts

Troubleshooting VPN connection proposals can be a challenging process, even for an expert. By combining AWS tools, detailed logs, and strategic testing, you can gain deeper visibility into the negotiation process and resolve these issues. Here are some additional resources you may find useful:

• AWS Site-to-Site VPN Troubleshooting Guide
• CloudWatch Logs Insights
• VPN Connection Parameters

Gary, your expertise as an AWS Expert makes a difference in the community, and your efforts to refine secure VPN setups are truly inspiring. I hope these steps help you uncover the information you need and resolve the issue efficiently. Please feel free to reach out if you have more questions or need further assistance! 😊

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Farewell

Thanks again for being a valued member of the AWS community, Gary. Your contributions and insights help everyone level up. Good luck, and keep being awesome! 🚀

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Cheers,

Aaron 😊