Subnet

Definition

A subdivision of a virtual network that segments resources by IP range for security, organization, routing control, and efficient management.

Use Cases

• Stripe: PCI-Compliant Architecture — Uses private subnets to isolate payment processing from public traffic (Maintains PCI DSS Level 1 compliance for billions in transactions)

Provider Equivalents

• AWS: Subnet
• Azure: Subnet
• GCP: Subnetwork
• OCI: Subnet

Frequently Asked Questions

Public vs private subnet?

Public subnets have direct internet access via Internet Gateway. Private subnets access internet only through NAT Gateway for outbound traffic.

How do I size my subnets?

Use CIDR notation. /24 gives 256 IPs (251 usable), /20 gives 4096 IPs. Plan for growth - it's hard to resize subnets later.

Category: networking

Difficulty: intermediate

Related Terms

• VPC
• CIDR
• Private Subnet
• Route Table

See Also

• Internet
• WiFi
• Router
• Bandwidth
• Load Balancer