Governance Policies Azure Networking Virtual Network

Virtual Network

Governance policies for Virtual Network

Domain: azure-networking

Patterns

Name	Description
VNet with delegated subnets and NSGs	Complete VNet deployment with purpose-specific subnets, delegations, and NSGs

Anti-Patterns

Description	Instead
Do not create subnets without NSGs	Attach an NSG to every subnet
Do not use a single large subnet for all services	Create purpose-specific subnets with appropriate delegations
Do not use /8 or /16 address spaces for POC	Use /20 or /22 for POC; plan for future growth without waste

References

• Virtual network planning
• Network security groups
• Subnet delegation

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Checks (5)

Check	Severity	Description
AZ-VNET-001	Required	Create Virtual Network with planned address space and purpose-specific subnets
AZ-VNET-002	Required	Create Network Security Groups with explicit rules for every subnet
AZ-VNET-003	Required	Use proper subnet delegation for Azure services that require it
AZ-VNET-004	Required	Plan subnet sizes according to service requirements
AZ-VNET-005	Recommended	Use standard naming convention for subnets: snet-{purpose}

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AZ-VNET-001

Create Virtual Network with planned address space and purpose-specific subnets

Severity: Required
Rationale: Address space must be planned to avoid overlap; subnets must be sized for their workload type
Agents: terraform-agent, bicep-agent, cloud-architect

Targets

• Microsoft.Network/virtualNetworks

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AZ-VNET-002

Create Network Security Groups with explicit rules for every subnet

Severity: Required
Rationale: NSGs provide network-level access control; every subnet must have an NSG to enforce least-privilege traffic flow
Agents: terraform-agent, bicep-agent, cloud-architect

Targets

• Microsoft.Network/virtualNetworks

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AZ-VNET-003

Use proper subnet delegation for Azure services that require it

Severity: Required
Rationale: Services like App Service, Container Apps, and others require subnet delegation to function correctly
Agents: terraform-agent, bicep-agent, cloud-architect

Targets

• Microsoft.Network/virtualNetworks

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AZ-VNET-004

Plan subnet sizes according to service requirements

Severity: Required
Rationale: App Service VNet integration needs /26 minimum; Container Apps needs /23 minimum; PE subnets need /27 minimum
Agents: cloud-architect, terraform-agent, bicep-agent

Targets

• Microsoft.Network/virtualNetworks

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AZ-VNET-005

Use standard naming convention for subnets: snet-{purpose}

Severity: Recommended
Rationale: Consistent naming enables automation and reduces configuration errors
Agents: terraform-agent, bicep-agent, cloud-architect

Targets

• Microsoft.Network/virtualNetworks

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