OCI Best Practices

NEVER Do This

❌ NEVER create a VCN with /24 or smaller CIDR — it cannot be expanded

# WRONG - only 256 IPs, exhausted quickly, cannot expand
oci network vcn create --cidr-block "10.0.0.0/24"

# RIGHT - start with /16 (65,536 IPs, room for 256 /24 subnets)
oci network vcn create --cidr-block "10.0.0.0/16"
# OCI supports /16 to /30

Migration cost: Must create new VCN and migrate everything — hours of downtime, IP changes, security rule updates.