Networking concepts

The rest of the AWS networking section assumes a working knowledge of IP addressing and routing. This section is where that background lives, so the service pages can stay focused on the service.

Start with networking fundamentals. It covers the OSI layers and where AWS’s responsibility ends, TCP versus UDP, ephemeral ports, and the addresses AWS reserves in every subnet. For address planning, CIDR range examples is the quick reference, and the private IPv4 address planning page explains how to pick ranges that will not collide when networks are joined later. VPC routing and BGP covers how a route table resolves a destination.

The remaining pages are about the network interface of an EC2 instance itself: elastic network interfaces, enhanced networking, and the Elastic Fabric Adapter for high-performance computing and machine learning workloads.