AWS ENI, EN & EFA
2 min readFeb 22, 2021
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:
- Elastic Network Adapter(ENA) → Supports network speeds of up to 100Gbps
- 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