VNET Size
Regional Network
Range
CIDR
Number of Virtual Networks
Size of Virtual Network
Mask
Number of Subnets per VNET
Size of Subnet
Mask
Convert IP Address
IP Address
Decimal
Binary
CIDR to Range
IP Address and CIDR
CIDR
Start:
End:
Range to CIDR
IP Addresses
CIDRs
Reserved Subnet Name | Min. Size of Subnet | Max. Size of Subnet | Recommended Size of Subnet | Related Azure Services |
|---|---|---|---|---|
| GatewaySubnet | /27 | /27 | /27 | Azure Virtual Network Gateway / ExpressRoute / Site-to-Site VPN |
| RouteServerSubnet | /27 | /24 | /27 | Azure Route Server |
| AzureBastionSubnet | /26 | /24 | /26 | Azure Bastion |
| AzureFirewallSubnet | /26 | /26 | /26 | Azure Firewall |
| AzureFirewallManagementSubnet | /26 | /16 | /26 | Azure Firewall Manager |
Delegated Services Name | Min. Size of Subnet | Max. Size of Subnet | Recommended Size of Subnet | Related Azure Services |
|---|---|---|---|---|
| Microsoft.DBforPostgreSQL/flexibleServers | /28 | /27 | /27 | Azure Database for PostgreSQL - Flexible Server |
| Microsoft.Web/serverFarms | /26 | /27 | /27 | Azure App Service |
| Microsoft.Network/dnsResolvers | /28 | N/A | /28 | Azure Private DNS Resolver (inbound) |
| Microsoft.Network/dnsResolvers | /28 | N/A | /28 | Azure Private DNS Resolver (outbound) |
| Microsoft.AVS/privateClouds | /22 | /22 | /22 | Azure VMware Solution |
Azure PaaS | Min. Size of Subnet | Max. Size of Subnet | Recommended Size of Subnet | Dedicated Subnet |
|---|---|---|---|---|
| Azure Virtual WAN Hub | /24 | N/A | /24 | Yes |
| Azure Application Gateway | /26 (Standard or WAF SKU) | N/A | /24 (Standard_v2 or WAF_v2 SKU) | Yes |
| Azure AD Domain Services (AADDS) | ? | N/A | ? | No |
| Azure SQL Managed Instance (SQL MI) | /27 | N/A | /26 | Yes |
| App Services (Web Apps, Function, API Apps) | /28 | N/A | /26 | Yes |
| Azure API Management | ? | N/A | ? | Yes |
| Azure Container Instances (ACI) | ? | N/A | ? | Yes |
| Azure Spring Cloud | /28 | N/A | Depends on Requirement | Yes |
| Azure Red Hat OpenShift Master Subnet | /27 | /27 | /27 | Yes |
| Azure Red Hat OpenShift Worker Subnet | /27 | /24 | /25 | Yes |
The tables above were taken from Visual Subnet Calculator (Azure Edition) (https://blog.pichuang.com.tw/azure-subnets.html)