DNS Node A Records

DOCUMENT CATEGORY: Runbook SCOPE: DNS configuration for cluster nodes PURPOSE: Pre-create A records for Azure Local nodes MASTER REFERENCE: Microsoft Learn - Network Requirements

Status: Active

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Overview

Pre-create forward lookup A records for each Azure Local node hostname before deployment.

What This Accomplishes

• DNS name resolution for cluster nodes
• Pre-staged DNS records for controlled environments
• Documentation of hostname to IP mappings

info

The active directory information in these documents should have been decided in the planning phase and discovery phases. These are just examples. Please update your scripts with the right OU information, right security groups, DNS, etc.

Prerequisites

• DNS Manager access or DNS Server tools
• Node hostnames and management IP addresses
• Authoritative DNS server permissions

Variables from variables.yml

Variable Path	Type	Description
identity.active_directory.domain.fqdn	string	DNS zone name (AD domain FQDN)
cluster_arm_deployment.arc_node_resource_ids	list	Node resource IDs (hostnames extracted)
cluster_arm_deployment.starting_ip	string	Starting management IP for node A records

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DNS Record Creation

Pre-create forward lookup A records for each Azure Local node hostname. Do NOT create cluster name (CNO) or virtual client access name (VCO) records now—those are generated later by the failover cluster process.

DNS Manager

1. Open DNS Manager on an authoritative domain DNS server.
2. Expand Forward Lookup Zones → select the Active Directory–integrated zone (for example, hybrid.mgmt).
3. For each node:

• Right‑click the zone → New Host (A or AAAA).
• Enter node name (for example, hcinode01) and its management IPv4 address.
• Leave "Create associated PTR record" unchecked unless the reverse zone is already delegated and managed.
• Click Add Host.

4. Repeat for all node hostnames (example: hcinode01, hcinode02, hcinode03, hcinode04).
5. Document the mapping (hostname ↔ IP) in the deployment artifacts and store in version control.

Orchestrated Script (Mgmt Server)

When to use: Managing from a domain-joined management server — config-driven via variables.yml

Script

Primary: scripts/deploy/03-onprem-readiness/phase-01-active-directory/task-03-dns-node-a-records/powershell/Invoke-DNSNodeRecords.ps1

Alternatives:

Variant	Path
Azure CLI	scripts/deploy/03-onprem-readiness/phase-01-active-directory/task-03-dns-node-a-records/azure-cli/Invoke-DNSNodeRecords.ps1
Bash	scripts/deploy/03-onprem-readiness/phase-01-active-directory/task-03-dns-node-a-records/bash/invoke-dns-node-records.sh

Code

# ============================================================================
# Script: Invoke-DNSNodeRecords.ps1
# Execution: Run FROM management server — reads variables.yml
# Prerequisites: powershell-yaml module, DnsServer RSAT, DNS admin access
# ============================================================================

param(
 [Parameter(Mandatory = $false)]
 [string]$ConfigPath
)

$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
if ($ConfigPath) {
 $ConfigFile = $ConfigPath
} else {
 $ConfigFile = Join-Path $ScriptDir "..\..\..\..\config\variables.yml"
}
if (!(Test-Path $ConfigFile)) { throw "variables.yml not found at $ConfigFile" }

Import-Module powershell-yaml -ErrorAction Stop
Import-Module DnsServer

$config = ConvertFrom-Yaml (Get-Content -Path $ConfigFile -Raw) -Ordered
$zoneName = $config["active_directory"]["domain"]["fqdn"]

# Build node map from cluster ARM deployment node names and starting IP
# Update variables.yml: active_directory section with node records if defined,
# otherwise populate $nodeMap from your site planning documentation.
$nodeMap = [ordered]@{}
$nodeIds = $config["cluster_arm_deployment"]["arc_node_resource_ids"]
if ($nodeIds) {
 $startIp = [System.Net.IPAddress]::Parse($config["cluster_arm_deployment"]["starting_ip"])
 $bytes = $startIp.GetAddressBytes()
 $offset = 0
 foreach ($id in $nodeIds) {
 $nodeName = ($id -split '/')[-1]
 $bytes[3] = [byte]([int]$bytes[3] + $offset)
 $nodeMap[$nodeName] = ([System.Net.IPAddress]::new($bytes)).ToString()
 $offset++
 }
}

if ($nodeMap.Count -eq 0) {
 Write-Warning "No nodes found in variables.yml — populate cluster_arm_deployment.arc_node_resource_ids or define nodes manually."
 return
}

Write-Host "[1/2] Creating DNS A records in zone: $zoneName" -ForegroundColor Cyan

foreach ($nodeName in $nodeMap.Keys) {
 $ip = $nodeMap[$nodeName]
 if (-not (Get-DnsServerResourceRecord -ZoneName $zoneName -Name $nodeName -RRType A -ErrorAction SilentlyContinue)) {
 Add-DnsServerResourceRecordA -ZoneName $zoneName -Name $nodeName -IPv4Address $ip `
 -AllowUpdateAny -CreatePtr:$false -TimeToLive (New-TimeSpan -Hours 1)
 Write-Host " Created: $nodeName.$zoneName -> $ip" -ForegroundColor Green
 } else {
 Write-Host " Exists: $nodeName.$zoneName" -ForegroundColor Yellow
 }
}

Write-Host "[2/2] Verifying A records..." -ForegroundColor Cyan
Get-DnsServerResourceRecord -ZoneName $zoneName -RRType A |
 Where-Object { $_.HostName -in $nodeMap.Keys } |
 Select-Object HostName, @{n='IPv4';e={$_.RecordData.IPv4Address}}

Validation

$zoneName = $config["active_directory"]["domain"]["fqdn"]
$nodeMap.Keys | ForEach-Object { Resolve-DnsName "$_.$zoneName" -ErrorAction SilentlyContinue | Select-Object Name, IPAddress }

Validation Script: scripts/validation/03-onprem-readiness/phase-01-active-directory/task-03-dns-node-a-records/powershell/Test-DNSNodeRecords.ps1

Standalone Script

#region CONFIGURATION
$ZoneName = "hybrid.mgmt"
$NodeMap = @{
 'hcinode01' = '10.50.10.11'
 'hcinode02' = '10.50.10.12'
 'hcinode03' = '10.50.10.13'
 'hcinode04' = '10.50.10.14'
}
#endregion

Import-Module DnsServer
foreach ($node in $NodeMap.Keys) {
 $ip = $NodeMap[$node]
 if (-not (Get-DnsServerResourceRecord -ZoneName $ZoneName -Name $node -RRType A -EA SilentlyContinue)) {
 Add-DnsServerResourceRecordA -ZoneName $ZoneName -Name $node -IPv4Address $ip `
 -AllowUpdateAny -CreatePtr:$false -TimeToLive (New-TimeSpan -Hours 1)
 Write-Host "Created: $node.$ZoneName -> $ip" -ForegroundColor Green
 }
}
Get-DnsServerResourceRecord -ZoneName $ZoneName -RRType A | Where-Object { $_.HostName -in $NodeMap.Keys } |
 Select-Object HostName, @{n='IPv4';e={$_.RecordData.IPv4Address}}

Verification

$ZoneName = (Get-ADDomain).DNSRoot
'hcinode01','hcinode02','hcinode03','hcinode04' | ForEach-Object { Resolve-DnsName "$_.${ZoneName}" -ErrorAction SilentlyContinue | Select Name,IPAddress }

Notes

• Only node hostnames are created now; cluster CNO/VCO records are deferred until cluster creation.
• If dynamic secure updates are allowed and change control permits, this step can be skipped; retain the section for controlled environments.
• Reverse (PTR) records are optional; create only if the reverse zone is already in scope.

Validation Checklist

• DNS Manager or PowerShell access available
• Node hostnames and IPs documented
• A records created for all nodes
• Records resolve correctly
• Mappings documented in deployment artifacts

Next Steps

After configuring DNS records, proceed to Task 4 - Service & Admin Accounts for account creation.

Troubleshooting

Common Issues

DNS Record Creation Fails: Check DNS server permissions and zone access.

Records Not Resolving: Verify DNS server configuration and replication.

Dynamic Updates Blocked: Use manual creation in controlled environments.

Support Resources

• DNS Record Management
• Azure Local DNS Requirements

Navigation

← Task 02: Security Groups	↑ Part 3: On-Premises Readiness	Task 04: Service & Admin Accounts →

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Version Control

Version	Date	Author	Changes
1.0	2026-01-31	Azure Local Cloud Azure Local Cloudnology	Initial document
1.1	2026-03-03	Azure Local Cloud Azure Local Cloudnology	Standardized runbook format

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