Introduction to AWS Interconnect Technology from a Distributed Training Perspective – AWS Interconnect-Based Technology, Introduction to ENI | Amazon Web Services

AWS published a technical post explaining how ENIs work as the virtual network layer for EC2, especially on high-end GPU instances.

The blog distinguishes Primary vs. Secondary ENIs and clarifies ENA-only versus EFA-only networking modes.

It also shows how multiple network cards and ENIs are mapped on instances such as p5.48xlarge and p6-b200.48xlarge.

The guidance matters for distributed training because correct ENI and EFA setup affects bandwidth, latency, and NCCL communication performance.