How do you enable Enhanced Networking for an EC2 instance?

0-2 years experience

1. 1You have just launched a t3.medium instance and need the best possible network performance. How would you enable Enhanced Networking on it?
2. 2If you try to attach an ENA driver to an older instance type and it fails, what steps would you take to resolve the issue?
3. 3What command would you run on a Linux EC2 instance to verify that Enhanced Networking is active?

2-5 years experience

1. 1Your application is experiencing higher latency after moving to a c5.large instance. You suspect the ENA driver isn’t loaded. Walk me through how you would diagnose and fix it.
2. 2When launching a mixed fleet of instances via CloudFormation, how would you ensure all instances have Enhanced Networking enabled, and what trade‑offs might you consider?
3. 3During a blue‑green deployment, the new version on an m5.large instance cannot achieve expected throughput. Explain how you would check whether Enhanced Networking is correctly configured and what fallback options exist.

5-8 years experience

1. 1You need to design a high‑throughput data ingestion pipeline that uses dozens of c5n instances. How would you architect the networking layer, including enabling Enhanced Networking, to avoid bottlenecks at scale?
2. 2A recent kernel upgrade caused ENA driver failures on a fleet of production instances, leading to packet loss. Describe your incident response and how you would redesign the deployment process to prevent recurrence.
3. 3When migrating from an older generation of instances that use the Intel 82599 VF driver to ENA‑based instances, what compatibility and performance considerations must you address?

8+ years experience

1. 1Our organization plans to migrate thousands of legacy instances across multiple AWS accounts to ENA‑enabled instance types over the next year. What strategy would you propose to orchestrate this migration while minimizing downtime and ensuring security compliance?
2. 2How would you evaluate the cost‑benefit of enabling Enhanced Networking versus using AWS Nitro Enclaves for a multi‑tenant SaaS platform that requires strict isolation and high network throughput?
3. 3In a cross‑region, multi‑account architecture, how would you standardize the enablement and monitoring of Enhanced Networking to provide consistent performance metrics for all teams?