Chloe McAree (McAteer)
Published on



This is part of a blog series giving a high level overview of the different services examined on the AWS Solution Architect Associate exam, to view the whole series click here.

Elastic Network Interface (ENI) Summary

  • Essentially a virtual network card that can be attached to instances within your VPC.

  • Used to enable network connectivity for your instances.

  • Can use multiple network interfaces to create a management network.

  • Used for low budget and highly available solutions.

Enhanced Networking (EN) Summary

  • Uses single root I/O virtualisation to provide high performance networking.

  • Provides higher bandwidth and packets per second

  • No additional charges for EN, but your EC2 instances needs to support it

  • You would use EN instead of ENI when you have more network throughput.

  • Used when you need a reliably high throughput and speeds between 10–100Gbps.

Depending on instance type EN can enable:

  1. Elastic Network Adapter(ENA) → Supports network speeds of up to 100Gbps

  2. Intel 82599 Virtual Function (VF) → Supports network speeds up to 10Gbps, used for older instances.

Elastic Fabric Adapter (EFA) Summary

  • Network device you attach to EC2 instances to accelerate High Performance Computing (HPC) & ML applications.

  • Can use OS Bypass to by pass operating system and communicate directly with EFA device which enhances inter-instance communications

  • Can scale to thousands of CPUs or GPUs