Task 06: Network Security Groups
DOCUMENT CATEGORY: Runbook SCOPE: NSG deployment and association PURPOSE: Secure management and bastion subnets with NSG rules MASTER REFERENCE: Microsoft Learn - NSG Overview
Status: Active
Overview
This task creates two Network Security Groups (NSGs) and associates them with the management subnet and AzureBastionSubnet. These NSGs enforce least-privilege network access for Bastion traffic, CI/CD runner access, and on-premises connectivity.
Task Classification
Execution Target: Azure-Only (control-plane API operation) Tab Profile: 3 tabs — Azure Portal · Azure CLI / PowerShell · Standalone Script
Terraform Reference
Module: azurelocal-toolkit
File: nsg.tf
Mode: Management
Components Created
| Resource | Name Pattern | Purpose |
|---|---|---|
| NSG (Management) | nsg-azrl-{env}-{region}-01 | Management subnet security |
| NSG (Bastion) | nsg-bastion-{env}-{region}-01 | AzureBastionSubnet security |
| Subnet Association (2x) | — | Bind NSGs to subnets |
Management NSG Rules
| Priority | Name | Direction | Source | Destination Ports | Action |
|---|---|---|---|---|---|
| 110 | Bastion-SSH-RDP-Inbound | Inbound | AzureBastionSubnet CIDR | 22, 3389 | Allow |
| 120 | Azure Local Cloud-Runners-SSH-Inbound | Inbound | CI/CD runner subnet | 22 | Allow |
| 130 | Azure-Local-OnPrem-Inbound | Inbound | On-prem mgmt + OOB CIDRs | * | Allow |
Bastion NSG Rules (Microsoft Required)
| Priority | Name | Direction | Source | Destination Ports | Action |
|---|---|---|---|---|---|
| 120 | AllowHttpsInbound | Inbound | Internet | 443 | Allow |
| 130 | AllowGatewayManagerInbound | Inbound | GatewayManager | 443 | Allow |
| 140 | AllowAzureLoadBalancerInbound | Inbound | AzureLoadBalancer | 443 | Allow |
| 150 | AllowBastionHostCommunicationInbound | Inbound | VirtualNetwork | 80, 5701 | Allow |
| 120 | AllowSSHRDPOutbound | Outbound | * | 22, 3389 | Allow |
| 130 | AllowAzureCloudOutbound | Outbound | * | 443 | Allow |
| 140 | AllowBastionCommunicationOutbound | Outbound | VirtualNetwork | 5701, 8080 | Allow |
| 150 | AllowSessionOutbound | Outbound | * | 80 | Allow |
| 4090 | DenyAllOutbound | Outbound | * | * | Deny |
Prerequisites
- Task 01: Virtual Network completed — Subnets exist
- On-premises management and OOB CIDRs confirmed
- CI/CD runner subnet CIDR confirmed (if applicable)
Variables from variables.yml
| Variable | Config Path | Example (IIC) |
|---|---|---|
| Subscription ID | azure.subscriptions.<name>.id | (per environment) |
| Resource Group | network.azure_vnets.management.resource_group | rg-azrlmgmt-azl-eus-01 |
| Bastion Subnet CIDR | network.azure_vnets.management.subnets.bastion.cidr | 10.250.1.64/26 |
| Management Subnet CIDR | network.azure_vnets.management.subnets.management.cidr | 10.250.1.32/27 |
Single Subscription Model
Landing Zone Placement
| Field | Value | Config Path |
|---|---|---|
| Subscription | Customer subscription | azure.subscriptions.<name>.id |
| Resource Group | rg-azrlmgmt-{env}-{region}-01 | network.azure_vnets.management.resource_group |
| Management NSG | nsg-azrl-{env}-{region}-01 | Derived from naming convention |
| Bastion NSG | nsg-bastion-{env}-{region}-01 | Derived from naming convention |
Execution Options
- Azure Portal
- Azure CLI / PowerShell
- Standalone Script
Azure Portal
When to use: Learning Azure Local, single deployment, prefer visual interface
Procedure — Management NSG
- Create NSG:
- Search for Network security groups → + Create
| Field | Value | Source |
|-------|-------|--------|
| Name |
nsg-azrl-{env}-{region}-01| Naming convention | | Region | Your region |azure.region| | Resource Group | Management RG |network.azure_vnets.management.resource_group|
- Add Inbound Rules — Navigate to Inbound security rules → + Add for each:
Rule 1: Bastion SSH/RDP
| Field | Value |
|---|---|
| Source | IP Addresses |
| Source IP | AzureBastionSubnet CIDR |
| Destination port ranges | 22, 3389 |
| Protocol | Any |
| Action | Allow |
| Priority | 110 |
| Name | Bastion-SSH-RDP-Inbound |
Rule 2: CI/CD Runners SSH
| Field | Value |
|---|---|
| Source | IP Addresses |
| Source IP | CI/CD runner subnet CIDR |
| Destination port ranges | 22 |
| Priority | 120 |
| Name | Azure Local Cloud-Runners-SSH-Inbound |
Rule 3: On-Prem Inbound
| Field | Value |
|---|---|
| Source | IP Addresses |
| Source IPs | On-prem mgmt CIDR, OOB CIDR |
| Destination port ranges | * |
| Priority | 130 |
| Name | Azure-Local-OnPrem-Inbound |
- Associate NSG to Management Subnet:
- NSG → Subnets → + Associate → Select VNet and management subnet
Procedure — Bastion NSG
- Create Bastion NSG:
- Create second NSG named
nsg-bastion-{env}-{region}-01
-
Add Required Bastion Rules: Add all inbound/outbound rules per the Bastion NSG Rules table above. These are Microsoft-required for Bastion to function.
-
Associate NSG to AzureBastionSubnet:
- NSG → Subnets → + Associate → Select AzureBastionSubnet
Validation
- Both NSGs created with correct rules
- Management NSG associated with management subnet
- Bastion NSG associated with AzureBastionSubnet
- Bastion connectivity still works (Task 05)
Links
Azure CLI / PowerShell
When to use: Scripted Azure operations from management workstation or pipeline — config-driven via
variables.yml
Script
Primary: scripts/deploy/02-azure-foundation/phase-04-azure-management-infrastructure/task-06-network-security-groups/powershell/Deploy-LighthouseNsg.ps1
Alternatives:
| Variant | Path |
|---|---|
| PowerShell + Azure CLI | task-06-network-security-groups/azure-cli/Deploy-LighthouseNsg.azcli.ps1 |
| Bash + Azure CLI | task-06-network-security-groups/bash/invoke-network-security-groups.sh |
Code
# ============================================================================
# Script: Deploy-LighthouseNsg.ps1
# Execution: Run from management workstation — reads variables.yml
# Prerequisites: Az.Network module, authenticated to Azure
# ============================================================================
#Requires -Modules Az.Network, Az.Resources
param(
[Parameter(Mandatory = $false)]
[ValidateScript({Test-Path $_})]
[string]$ConfigPath = "config/variables.yml"
)
$ErrorActionPreference = "Stop"
$scriptRoot = $PSScriptRoot
. "$scriptRoot/../../../../../common/utilities/helpers/config-loader.ps1"
. "$scriptRoot/../../../../../common/utilities/helpers/logging.ps1"
$config = Get-InfrastructureConfig -ConfigPath $ConfigPath
# Extract values
$SubscriptionId = $config.azure.subscriptions.($config.network.azure_vnets.management.subscription).id
$ResourceGroup = $config.network.azure_vnets.management.resource_group
$Location = $config.network.azure_vnets.management.location
$VNetName = $config.network.azure_vnets.management.name
$BastionSubnetCidr = $config.network.azure_vnets.management.subnets.bastion.cidr
$MgmtSubnetName = $config.network.azure_vnets.management.subnets.management.name
$OnPremMgmtCidr = $config.network.vlans.management.cidr
$OnPremOobCidr = $config.network.vlans.oob.cidr
Set-AzContext -SubscriptionId $SubscriptionId | Out-Null
# ── Management NSG ──
$mgmtNsgName = "nsg-azrl-$($config.azure.environment)-$($config.azure.region_abbreviation)-01"
Write-LogInfo "Creating Management NSG: $mgmtNsgName"
$rule1 = New-AzNetworkSecurityRuleConfig -Name "Bastion-SSH-RDP-Inbound" -Priority 110 `
-Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix $BastionSubnetCidr `
-SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange @("22","3389")
$rule2 = New-AzNetworkSecurityRuleConfig -Name "Azure Local Cloud-Runners-SSH-Inbound" -Priority 120 `
-Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix $config.network.azure_vnets.cicd.subnets.cicd.cidr `
-SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "22"
$rule3 = New-AzNetworkSecurityRuleConfig -Name "Azure-Local-OnPrem-Inbound" -Priority 130 `
-Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix @($OnPremMgmtCidr, $OnPremOobCidr) `
-SourcePortRange "*" -DestinationAddressPrefix $config.network.azure_vnets.management.subnets.management.cidr `
-DestinationPortRange "*"
$mgmtNsg = New-AzNetworkSecurityGroup -Name $mgmtNsgName -ResourceGroupName $ResourceGroup `
-Location $Location -SecurityRules @($rule1, $rule2, $rule3)
# ── Bastion NSG ──
$bastionNsgName = "nsg-bastion-$($config.azure.environment)-$($config.azure.region_abbreviation)-01"
Write-LogInfo "Creating Bastion NSG: $bastionNsgName"
$bastionRules = @(
(New-AzNetworkSecurityRuleConfig -Name "AllowHttpsInbound" -Priority 120 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "Internet" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowGatewayManagerInbound" -Priority 130 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "GatewayManager" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowAzureLoadBalancerInbound" -Priority 140 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "AzureLoadBalancer" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowBastionHostCommunicationInbound" -Priority 150 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "VirtualNetwork" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("80","5701")),
(New-AzNetworkSecurityRuleConfig -Name "AllowSSHRDPOutbound" -Priority 120 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("22","3389")),
(New-AzNetworkSecurityRuleConfig -Name "AllowAzureCloudOutbound" -Priority 130 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "AzureCloud" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowBastionCommunicationOutbound" -Priority 140 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "VirtualNetwork" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("5701","8080")),
(New-AzNetworkSecurityRuleConfig -Name "AllowSessionOutbound" -Priority 150 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "80"),
(New-AzNetworkSecurityRuleConfig -Name "DenyAllOutbound" -Priority 4090 -Direction Outbound -Access Deny -Protocol "*" -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "*")
)
$bastionNsg = New-AzNetworkSecurityGroup -Name $bastionNsgName -ResourceGroupName $ResourceGroup `
-Location $Location -SecurityRules $bastionRules
# ── Associate NSGs to Subnets ──
$vnet = Get-AzVirtualNetwork -Name $VNetName -ResourceGroupName $ResourceGroup
Write-LogInfo "Associating Management NSG to subnet: $MgmtSubnetName"
$mgmtSubnet = Get-AzVirtualNetworkSubnetConfig -Name $MgmtSubnetName -VirtualNetwork $vnet
Set-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name $MgmtSubnetName `
-AddressPrefix $mgmtSubnet.AddressPrefix -NetworkSecurityGroupId $mgmtNsg.Id | Out-Null
Write-LogInfo "Associating Bastion NSG to AzureBastionSubnet"
Set-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name "AzureBastionSubnet" `
-AddressPrefix $config.network.azure_vnets.management.subnets.bastion.cidr `
-NetworkSecurityGroupId $bastionNsg.Id | Out-Null
$vnet | Set-AzVirtualNetwork | Out-Null
Write-LogSuccess "NSGs created and associated successfully"
Validation
Get-AzNetworkSecurityGroup -ResourceGroupName $ResourceGroup | Format-Table Name, @{N="Rules";E={$_.SecurityRules.Count}}, ProvisioningState
Standalone Script
When to use: Copy-paste ready script — no config file, no helpers needed.
Code
# ============================================================================
# Script: Deploy-NetworkSecurityGroups-Standalone.ps1
# Execution: Run anywhere — fully self-contained
# Prerequisites: Az.Network module, authenticated to Azure
# ============================================================================
#Requires -Modules Az.Network, Az.Resources
#region CONFIGURATION
# ── Edit these values to match your environment ──────────────────────────────
$SubscriptionId = "00000000-0000-0000-0000-000000000000"
$ResourceGroup = "rg-azrlmgmt-azl-eus-01"
$Location = "eastus"
$VNetName = "vnet-azrl-azl-eus-01"
$MgmtNsgName = "nsg-azrl-azl-eus-01"
$BastionNsgName = "nsg-bastion-azl-eus-01"
$MgmtSubnetName = "snet-azrl-azl-eus-01"
$BastionSubnetCidr = "10.250.1.64/26"
$MgmtSubnetCidr = "10.250.1.32/27"
$OnPremMgmtCidr = "192.168.203.0/24"
$OnPremOobCidr = "10.245.64.0/24"
$CicdSubnetCidr = "10.250.0.0/24"
#endregion CONFIGURATION
Set-AzContext -SubscriptionId $SubscriptionId | Out-Null
# Management NSG
Write-Host "Creating Management NSG: $MgmtNsgName" -ForegroundColor Cyan
$r1 = New-AzNetworkSecurityRuleConfig -Name "Bastion-SSH-RDP-Inbound" -Priority 110 -Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix $BastionSubnetCidr -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange @("22","3389")
$r2 = New-AzNetworkSecurityRuleConfig -Name "Azure Local Cloud-Runners-SSH-Inbound" -Priority 120 -Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix $CicdSubnetCidr -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "22"
$r3 = New-AzNetworkSecurityRuleConfig -Name "Azure-Local-OnPrem-Inbound" -Priority 130 -Direction Inbound -Access Allow -Protocol "*" -SourceAddressPrefix @($OnPremMgmtCidr,$OnPremOobCidr) -SourcePortRange "*" -DestinationAddressPrefix $MgmtSubnetCidr -DestinationPortRange "*"
$mgmtNsg = New-AzNetworkSecurityGroup -Name $MgmtNsgName -ResourceGroupName $ResourceGroup -Location $Location -SecurityRules @($r1,$r2,$r3)
# Bastion NSG (Microsoft-required rules)
Write-Host "Creating Bastion NSG: $BastionNsgName" -ForegroundColor Cyan
$br = @(
(New-AzNetworkSecurityRuleConfig -Name "AllowHttpsInbound" -Priority 120 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "Internet" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowGatewayManagerInbound" -Priority 130 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "GatewayManager" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowAzureLoadBalancerInbound" -Priority 140 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "AzureLoadBalancer" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowBastionHostCommunicationInbound" -Priority 150 -Direction Inbound -Access Allow -Protocol Tcp -SourceAddressPrefix "VirtualNetwork" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("80","5701")),
(New-AzNetworkSecurityRuleConfig -Name "AllowSSHRDPOutbound" -Priority 120 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("22","3389")),
(New-AzNetworkSecurityRuleConfig -Name "AllowAzureCloudOutbound" -Priority 130 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "AzureCloud" -DestinationPortRange "443"),
(New-AzNetworkSecurityRuleConfig -Name "AllowBastionCommunicationOutbound" -Priority 140 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "VirtualNetwork" -SourcePortRange "*" -DestinationAddressPrefix "VirtualNetwork" -DestinationPortRange @("5701","8080")),
(New-AzNetworkSecurityRuleConfig -Name "AllowSessionOutbound" -Priority 150 -Direction Outbound -Access Allow -Protocol Tcp -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "80"),
(New-AzNetworkSecurityRuleConfig -Name "DenyAllOutbound" -Priority 4090 -Direction Outbound -Access Deny -Protocol "*" -SourceAddressPrefix "*" -SourcePortRange "*" -DestinationAddressPrefix "*" -DestinationPortRange "*")
)
$bastionNsg = New-AzNetworkSecurityGroup -Name $BastionNsgName -ResourceGroupName $ResourceGroup -Location $Location -SecurityRules $br
# Associate
$vnet = Get-AzVirtualNetwork -Name $VNetName -ResourceGroupName $ResourceGroup
Set-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name $MgmtSubnetName -AddressPrefix $MgmtSubnetCidr -NetworkSecurityGroupId $mgmtNsg.Id | Out-Null
Set-AzVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name "AzureBastionSubnet" -AddressPrefix $BastionSubnetCidr -NetworkSecurityGroupId $bastionNsg.Id | Out-Null
$vnet | Set-AzVirtualNetwork | Out-Null
Write-Host "NSGs created and associated" -ForegroundColor Green
No External Dependencies
Self-contained. Edit the #region CONFIGURATION block and run.
Validation
- Management NSG has 3 inbound rules
- Bastion NSG has all required rules (9 rules)
- Both NSGs associated with correct subnets
- Bastion connectivity still works
CAF/WAF Landing Zone Model
In the CAF/WAF model, NSGs follow the same pattern but are deployed in the Connectivity subscription where the VNet resides.
Landing Zone Placement
| Field | Value | Config Path |
|---|---|---|
| Subscription | Connectivity subscription | azure.subscriptions.connectivity.id |
| Resource Group | rg-azrlconn-{env}-{region}-01 | network.azure_vnets.management.resource_group |
Execution Options
- Azure Portal
- Azure CLI / PowerShell
- Standalone Script
Azure Portal
Follow the same procedure as Single Subscription → Azure Portal, targeting the Connectivity subscription.
Validation
- NSGs in Connectivity subscription
- Associated with correct subnets
Azure CLI / PowerShell
Same Script — Different Config
The orchestrated script is identical. variables.yml references the correct Connectivity subscription for CAF/WAF.
See the Single Subscription → Azure CLI / PowerShell tab.
Standalone Script
Update the #region CONFIGURATION block for Connectivity subscription:
#region CONFIGURATION
$SubscriptionId = "00000000-0000-0000-0000-000000000000" # Connectivity subscription ID
$ResourceGroup = "rg-azrlconn-azl-eus-01" # Connectivity resource group
# ... remaining values same as single-sub
#endregion CONFIGURATION
Validation
- NSGs deployed in Connectivity subscription
- Subnet associations correct
Troubleshooting
| Issue | Root Cause | Remediation |
|---|---|---|
| Bastion stops working after NSG | Missing required Bastion rules | Add all Microsoft-required Bastion inbound/outbound rules |
| SSH from runner fails | Priority or CIDR mismatch | Verify CI/CD subnet CIDR in rule 120 |
| On-prem cannot reach Azure VMs | NSG blocking on-prem to mgmt | Verify on-prem CIDRs in rule 130 |
| DenyAllOutbound blocks Bastion | Bastion outbound rules missing | Ensure outbound rules 120-150 exist before DenyAll at 4090 |
Navigation
| Previous | Up | Next |
|---|---|---|
| Task 05: Azure Bastion | Manual Deployment Index | Task 07: NAT Gateway |
Version Control
- Created: 2025-09-15 by Hybrid Cloud Solutions
- Last Updated: 2026-03-03 by Hybrid Cloud Solutions
- Version: 4.0.0
- Tags: azure-local, nsg, networking, security
- Keywords: NSG, network security group, firewall rules, subnet security, Bastion NSG
- Author: Hybrid Cloud Solutions