Azure Virtual Network Subnets
Subnets segment a virtual network (VNet) into one or more address ranges. Use subnets to organize and secure your Azure resources.
| Name | Address range | Associated resources | Network security group |
|---|---|---|---|
| frontend | 10.0.0.0/24 | App Service, Load Balancer | NSG-frontend |
| backend | 10.0.1.0/24 | VM Scale Set, Azure Kubernetes Service | NSG-backend |
| database | 10.0.2.0/24 | Azure SQL, Cosmos DB | NSG-db |
| gateway | 10.0.255.0/27 | VPN Gateway, ExpressRoute | NSG-gateway |
Creating a Subnet
- Navigate to the Azure portal and select your virtual network.
- Click Subnets and then Add subnet.
- Provide a name, address range, and optional network security group.
- Click Save to create the subnet.
Best Practices
- Plan address spaces to avoid overlap with on‑premises networks.
- Use separate subnets for different workload tiers (web, app, data).
- Apply network security groups at the subnet level for centralized security.
- Reserve IP ranges for future scaling.