AWS VPC: Public & Private Subnets with EC2 & Docker
Why do we need a custom VPC & Subnets? Without network isolation, every server you launch sits on a shared network accessible to anyone on the internet. A Virtual Private Cloud (VPC) gives you your own isolated private data center in the cloud. You decide which servers face the public internet and which backend databases stay completely shielded inside private subnets where no outsider can touch…
The Virtual Private Cloud (VPC) is a private data center in the cloud that gives users their own isolated network environment. Planning the VPC's CIDR block involves assigning an IPv4 range within certain standards, with a smaller number indicating a larger network. Subnets, which are slices of the VPC tied to a specific Availability Zone, are created within this private space.
Each subnet has five reserved AWS IPs that cannot be used for instances or databases. Route tables determine whether a subnet is public or private; a public subnet has a default route to an Internet Gateway, allowing outbound internet traffic. The Internet Gateway connects the VPC to the public internet, enabling instances within the subnet to communicate with external resources.
Security Groups and Network ACLs act as firewalls to control inbound and outbound traffic at different levels. In a multi-tier architecture, public subnets host load balancers and front-facing web servers, while private subnets house application workers and internal microservices, with isolated private subnets dedicated to databases. This setup ensures that no internet route touches customer data.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
