AWS Networking Services
Learn how networking works on AWS: Amazon VPC and its building blocks, VPC security with security groups and network ACLs, DNS with Amazon Route 53, and hybrid and private connectivity.
A VPC is the private network where almost everything you run on AWS lives, so networking is the layer that decides what can reach your resources and how they reach the outside world. This topic covers Amazon VPC and the services built around it: how you secure it, how DNS sends users to it, and how you connect it to other networks privately.
The lessons move from the network outward. You start by building a mental model of a VPC and its parts, then add the two firewalls that control its traffic, then look at Amazon Route 53 for DNS, and finish with the options for linking a VPC to on-premises networks and other VPCs without crossing the public internet.
What This Topic Covers
- the building blocks of an Amazon VPC: subnets, CIDR blocks, route tables, internet gateways, and NAT gateways
- the difference between public and private subnets, and why routing decides which is which
- VPC security with security groups (instance level, stateful) and network ACLs (subnet level, stateless)
- what DNS does and the three main functions of Amazon Route 53
- Route 53 routing policies and how health checks support failover
- hybrid and private connectivity with Site-to-Site VPN, AWS Direct Connect, VPC peering, AWS Transit Gateway, and VPC endpoints
Why It Matters
Networking questions on the exam rarely ask you to configure anything. They describe a need, like blocking a single IP address, sending users to the closest Region, or reaching Amazon S3 without an internet gateway, and ask which service fits. Once you can match the scenario to the right tool, these become some of the most predictable questions on the test.
This topic also connects to the rest of the course. Security groups and network ACLs are where the security domain becomes concrete, Route 53 ties into the global infrastructure and content delivery you met earlier, and the cost of moving data between networks feeds straight into the billing and pricing domain. A clear picture of the VPC makes all of those lessons easier to reason about.