Infrastructure & Operations › Cloud Computing

VPC

A private network in the cloud.

Backend Engineer · Mid-level Data Engineer · Mid-level

Also known as: virtual private cloud, vnet, virtual network

A VPC (virtual private cloud) is a private network you define inside a cloud provider. It has its own address range, split into subnets, plus routing, gateways and access rules. You launch resources — servers, databases, load balancers — into it, and it controls how they reach each other and the internet. AWS calls it a VPC, Google Cloud a VPC network, Azure a virtual network; the idea is the same.

VPC 10.0.0.0/16
 ├── subnet 10.0.1.0/24   (zone a)
 └── subnet 10.0.2.0/24   (zone b)

The classic mistake is assuming a VPC is secure by default. It’s a network boundary, not a firewall. Resources inside can usually reach each other unless you restrict them, and a subnet with a route to the internet is reachable from it. Add security groups and a deliberate public/private subnet layout.

Two more traps:

Address planning. The range you pick is hard to change once resources use it. Choose a generous block and leave room to grow; overlapping ranges make it painful to connect networks later.
The default VPC. Many accounts have one with permissive defaults. It works, so people build in it, and later find it doesn’t match the intended network design.

Key pieces you’ll configure: subnets and their routes, an internet gateway for public access, a NAT gateway for outbound-only access from private subnets, and DNS settings. To connect VPCs to each other or to your office, use peering or a VPN. See IP addressing, regions and zones, and how providers differ in cloud providers.