Azure Virtual Network Naming Conventions: VNet, Subnet, and NSG

Use the CAF prefixes vnet for Virtual Networks, snet for subnets, and nsg for Network Security Groups, for example vnet-payments-prod-eus-001 and snet-app-prod-eus-001. They allow alphanumerics, hyphens, underscores, and periods, and must start with a letter or number.

Networking resources in Azure form the backbone of every workload, and they multiply quickly. A single workload might have a VNet, three subnets, two NSGs, a route table, a NAT gateway, and several private endpoints. Without a consistent naming scheme, the relationship between these resources becomes opaque the moment someone outside your team looks at the portal.

This guide covers CAF compliant naming for Azure networking resources, with patterns for VNets, subnets, NSGs, and everything that connects them.

Virtual Network (VNet)

Attribute	Value
CAF prefix	vnet
Max length	64 characters
Allowed characters	Alphanumerics, hyphens, underscores, periods
Scope of uniqueness	Resource group

Standard pattern:

vnet-{workload}-{environment}-{region}-{instance}

Examples:

Workload	Environment	Region	VNet name
Payments	Production	East US	vnet-payments-prod-eus-001
HR portal	Development	West Europe	vnet-hrportal-dev-weu-001
Hub network	Production	East US	vnet-hub-prod-eus-001
Shared services	Production	East US	vnet-shared-prod-eus-001

Subnets

Subnets live inside a VNet and don’t need the environment or region in their name (they inherit that context from the VNet). Instead, name subnets by their function:

Attribute	Value
CAF prefix	snet
Max length	80 characters
Allowed characters	Alphanumerics, hyphens, underscores, periods

Pattern:

snet-{function}-{instance}

Examples:

Function	Subnet name
Application tier	snet-app-001
Data tier	snet-data-001
Web / DMZ tier	snet-web-001
Management / bastion	snet-mgmt-001
Private endpoints	snet-pe-001
Azure Kubernetes Service	snet-aks-001
Application Gateway	snet-agw-001

Note: Azure reserves several subnet names for specific services, GatewaySubnet, AzureBastionSubnet, AzureFirewallSubnet. Use those exact names for those services; don’t add a prefix.

Network Security Groups

NSGs should be named after what they protect, the subnet or network interface they’re associated with:

Attribute	Value
CAF prefix	nsg
Max length	80 characters
Allowed characters	Alphanumerics, hyphens, underscores, periods

Pattern (subnet-level NSG):

nsg-{subnet-function}-{environment}-{instance}

Examples:

Association	NSG name
App subnet, production	nsg-app-prod-001
Data subnet, production	nsg-data-prod-001
Web subnet, staging	nsg-web-stg-001
AKS subnet, production	nsg-aks-prod-001

Route Tables (User Defined Routes)

Attribute	Value
CAF prefix	rt
Max length	80 characters

Pattern:

rt-{workload}-{environment}-{region}-{instance}

Examples:

rt-payments-prod-eus-001
rt-hub-prod-eus-001

Private Endpoints

Private endpoints connect Azure services to your VNet via a private IP. Name them after both the target service and the service they’re protecting:

Attribute	Value
CAF prefix	pe
Max length	80 characters

Pattern:

pe-{target-resource-name}-{instance}

Examples:

Target	Private endpoint name
Key Vault kv-payments-prod-eus-001	pe-kv-payments-prod-eus-001
Storage stpaymentsprodeus001	pe-st-payments-prod-eus-001
SQL Server sql-payments-prod-eus	pe-sql-payments-prod-eus-001

NAT Gateway

CAF prefix	Max length
ng	80 characters

Pattern:

ng-{workload}-{environment}-{region}-{instance}

Public IP Addresses

Public IPs should describe what they’re attached to:

Attribute	Value
CAF prefix	pip
Max length	80 characters

Pattern:

pip-{attached-resource}-{environment}-{region}-{instance}

Examples:

pip-agw-payments-prod-eus-001     ← Application Gateway public IP
pip-bastion-prod-eus-001          ← Bastion host public IP
pip-ng-payments-prod-eus-001      ← NAT Gateway public IP

A complete VNet naming example

Here’s what a production networking stack looks like with all names applied:

vnet-payments-prod-eus-001
├── snet-web-001          (web/DMZ tier)
│   └── nsg-web-prod-001
├── snet-app-001          (application tier)
│   └── nsg-app-prod-001
├── snet-data-001         (data tier)
│   └── nsg-data-prod-001
├── snet-pe-001           (private endpoints)
│   ├── pe-kv-payments-prod-eus-001
│   └── pe-st-payments-prod-eus-001
└── snet-agw-001          (Application Gateway)
    └── pip-agw-payments-prod-eus-001

The naming makes the topology readable without opening any blade.

Naming in Terraform

variable "workload"    { default = "payments" }
variable "environment" { default = "prod" }
variable "region"      { default = "eus" }

resource "azurerm_virtual_network" "main" {
  name                = "vnet-${var.workload}-${var.environment}-${var.region}-001"
  resource_group_name = azurerm_resource_group.main.name
  location            = azurerm_resource_group.main.location
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "app" {
  name                 = "snet-app-001"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.1.0/24"]
}

resource "azurerm_network_security_group" "app" {
  name                = "nsg-app-${var.environment}-001"
  resource_group_name = azurerm_resource_group.main.name
  location            = azurerm_resource_group.main.location
}

resource "azurerm_subnet_network_security_group_association" "app" {
  subnet_id                 = azurerm_subnet.app.id
  network_security_group_id = azurerm_network_security_group.app.id
}

Naming in Bicep

param workload string = 'payments'
param environment string = 'prod'
param region string = 'eus'

resource vnet 'Microsoft.Network/virtualNetworks@2023-09-01' = {
  name: 'vnet-${workload}-${environment}-${region}-001'
  location: resourceGroup().location
  properties: {
    addressSpace: { addressPrefixes: ['10.0.0.0/16'] }
    subnets: [
      {
        name: 'snet-app-001'
        properties: { addressPrefix: '10.0.1.0/24' }
      }
      {
        name: 'snet-data-001'
        properties: { addressPrefix: '10.0.2.0/24' }
      }
    ]
  }
}

resource nsg 'Microsoft.Network/networkSecurityGroups@2023-09-01' = {
  name: 'nsg-app-${environment}-001'
  location: resourceGroup().location
  properties: {}
}

Summary

• VNets: vnet-{workload}-{environment}-{region}-{instance}
• Subnets: snet-{function}-{instance}, no env/region needed (inherited from VNet)
• NSGs: nsg-{subnet-function}-{environment}-{instance}
• Private endpoints: pe-{target-name}-{instance}, name after what they protect
• Reserved subnet names (GatewaySubnet, AzureBastionSubnet, AzureFirewallSubnet) must be used exactly as-is

Use AzureNamer to generate compliant names for all 200+ Azure resource types including every networking resource above.