Cloud Networking Basics

Cloud networking lets you define isolated, secure network environments in the cloud, controlling exactly how resources communicate with each other and with the internet.

Virtual Private Clouds

A Virtual Private Cloud (VPC) is an isolated, private network within a cloud provider's infrastructure, entirely under your control — you define its IP address range, subnets, and routing, just as you might design a traditional office network, but entirely in software.

Subnets and Security Groups

A VPC is typically divided into subnets — a public subnet for resources that need direct internet access (like a web server), and a private subnet for resources that should never be directly reachable from the internet (like a database). Security groups act as virtual firewalls, controlling exactly what traffic is allowed in and out of each resource.

Common Mistakes

• Placing a database directly in a public subnet with a public IP address, unnecessarily exposing it to the internet.
• Configuring overly permissive security group rules (like allowing all traffic from anywhere) out of convenience during development, and forgetting to tighten them for production.
• Not understanding the difference between a security group (attached to a specific resource) and a network-level firewall rule (applied to an entire subnet).
• Assuming a private subnet is automatically completely secure — proper security group and access control configuration is still essential.