OCI Networking — VCN, Subnets & Security Rules

Overview

Build a working OCI network from scratch using the Python SDK. OCI networking (VCN, subnets, security lists, NSGs, gateways) has more moving parts than AWS VPC. A misconfigured security list silently drops traffic with no error — just timeouts. This skill creates a complete network topology with public and private subnets, internet and NAT gateways, route tables, and Network Security Groups (NSGs).

Purpose: Build a production-ready VCN with proper routing and security rules that actually works on first deploy.

Prerequisites

• OCI Python SDK — pip install oci
• Config file at ~/.oci/config with fields: user, fingerprint, tenancy, region, key_file
• IAM policy — Allow group Developers to manage virtual-network-family in compartment <name>
• Python 3.8+

Instructions

Step 1: Create the VCN