Task 03: Create DHCP Reservations for Management NICs

DOCUMENT CATEGORY: Runbook SCOPE: Azure Local hardware provisioning PURPOSE: Pre-stage DHCP reservations for management NICs so nodes receive consistent IPs on first OS boot, enabling automated remote configuration MASTER REFERENCE: Phase 01: Hardware Provisioning

Status: Active

---

Overview

Optional Configuration

This task is optional but strongly recommended for enterprise deployments. Creating DHCP reservations for management NICs before OS installation enables automated IP discovery, eliminating manual console access or network scanning during initial configuration.

Benefits:

• Nodes receive a known, predictable IP the moment the OS boots for the first time
• Eliminates network scanning or manual console access during Stage 11/12 configuration
• Required for fully automated deployment pipelines
• Consistent IP addressing throughout the deployment lifecycle until static IPs are configured

Create DHCP reservations for in-band management NICs using MAC addresses from variables.yml (populated from Task 02 hardware discovery) and planned IPs from variables.yml. Although these interfaces are ultimately assigned static IPs during OS configuration, DHCP reservations provide consistent temporary addressing for remote automation workflows.

---

Prerequisites

Requirement	Description	Source
Task 02 Complete	Management NIC MACs populated in variables.yml	variables.yml: nodes.<name>.macs.onboard_port1
DHCP Server Access	FortiGate admin rights, Windows DHCP admin, or customer DHCP contact	Network team
Management Network Subnet	Management VLAN DHCP scope configured	variables.yml: network.vlans.management.cidr
Planned Management IPs	Assigned management IP per node	variables.yml: nodes.<name>.management_ip

---

Variables from variables.yml

Path	Type	Description
network.vlans.management.cidr	string	Management network CIDR (e.g., 192.168.203.0/24)
network.vlans.management.dhcp.provider	string	DHCP provider type (e.g., FortiGate Firewalls)
nodes.<name>.management_ip	string	Planned management NIC IP address per node
nodes.<name>.hostname	string	Node hostname
nodes.<name>.service_tag	string	Dell service tag
nodes.<name>.macs.onboard_port1	string	Management NIC (onboard port 1 / Management LOM) MAC address

---

Execution Options

Select the tab matching your DHCP infrastructure:

FortiGate DHCP

When to use: Azure Local Cloud-managed environments using FortiGate firewalls for DHCP

FortiGate Web UI

1. Open browser to https://<fortigate-ip> and log in with admin credentials
2. Navigate to Policy & Objects → DHCP Server
3. Select the DHCP server for the management network and click Edit
4. In the Reserved Addresses section, click Create New for each node:

• IP Address: nodes.<name>.management_ip from variables.yml
• MAC Address: nodes.<name>.macs.onboard_port1 from variables.yml
• Description: <hostname>-mgmt (Service Tag: <service-tag>)

5. Click OK to save

FortiOS CLI (from Management Server)

Connect via SSH from the management server and run the following for each node. Replace values with actual entries from variables.yml.

# ============================================================================
# FortiGate DHCP Reservation — FortiOS CLI
# Execution: SSH FROM management server TO FortiGate
# Prerequisites: SSH access to FortiGate, admin rights
# ============================================================================

ssh admin@<fortigate-ip>

config system dhcp server
 edit "<Management-DHCP-Server-Name>"
 config reserved-address
 edit "<hostname>-mgmt"
 set ip <nodes.<name>.management_ip>
 set mac <nodes.<name>.macs.onboard_port1>
 set description "Mgmt NIC for <hostname> (ST: <service_tag>)"
 next
 end
 next
end

save config
exit

Repeat the edit block for each node.

Validation

# Verify reservations on FortiGate
show system dhcp server | grep -A5 "mgmt"

Windows DHCP Server

When to use: Azure Local Cloud-managed environments using Windows Server DHCP

Windows DHCP Console

1. Run dhcpmgmt.msc on the DHCP server or an admin workstation with RSAT installed
2. Connect to the DHCP server
3. Expand server → IPv4 → Scope [Management Network] → Reservations
4. Right-click Reservations → New Reservation for each node:

• Reservation name: <hostname>-mgmt
• IP address: nodes.<name>.management_ip from variables.yml
• MAC address: nodes.<name>.macs.onboard_port1 from variables.yml
• Description: Mgmt NIC for <hostname> (Service Tag: <service-tag>)
• Click Add

Orchestrated Script (Mgmt Server)

scripts/deploy/04-cluster-deployment/phase-01-hardware-provisioning/task-03-create-dhcp-reservations-for-management-nics/powershell/Invoke-MgmtNicDHCPReservations.ps1

#Requires -Version 7.0
# ============================================================================
# Script: Invoke-MgmtNicDHCPReservations.ps1
# Execution: Run FROM management server — PSRemoting to Windows DHCP server
# Prerequisites: powershell-yaml, PSRemoting to DHCP server, DHCP admin rights
# ============================================================================

param(
 [Parameter(Mandatory = $false)]
 [string]$ConfigPath = ".\config\variables.yml",

 [Parameter(Mandatory = $false)]
 [string]$DHCPServerOverride
)

Import-Module powershell-yaml -ErrorAction Stop
$config = Get-Content $ConfigPath -Raw | ConvertFrom-Yaml

$MgmtScopeId = ($config.network.vlans.management.cidr -split '/')[0]
$DHCPServer = if ($DHCPServerOverride) { $DHCPServerOverride } else { $config.network.vlans.management.dhcp.server }

Write-Host "Creating management NIC DHCP reservations on $DHCPServer (Scope: $MgmtScopeId)..." -ForegroundColor Cyan

foreach ($nodeKey in $config.nodes.Keys) {
 $node = $config.nodes[$nodeKey]
 $macFmt = $node.macs.onboard_port1 -replace ':', '-'
 $resName = "$($node.hostname)-mgmt"
 $resDesc = "Mgmt NIC for $($node.hostname) (ST: $($node.service_tag))"

 Write-Host " $resName -> $($node.management_ip)" -ForegroundColor Yellow

 Invoke-Command -ComputerName $DHCPServer -ScriptBlock {
 param($ScopeId, $IP, $MAC, $Name, $Desc)
 Add-DhcpServerv4Reservation `
 -ScopeId $ScopeId `
 -IPAddress $IP `
 -ClientId $MAC `
 -Name $Name `
 -Description $Desc
 } -ArgumentList $MgmtScopeId, $node.management_ip, $macFmt, $resName, $resDesc

 Write-Host " Created" -ForegroundColor Green
}

Write-Host "Done." -ForegroundColor Green

Standalone Script

#Requires -Version 5.1
# ============================================================================
# Script: Invoke-MgmtNicDHCPReservations-Standalone.ps1
# Execution: Run FROM any workstation with DHCP admin rights
# Prerequisites: RSAT-DHCP or run directly on DHCP server
# ============================================================================

#region CONFIGURATION
$DHCPServer = "dhcp01.corp.example.com" # Windows DHCP server hostname
$MgmtScopeId = "192.168.203.0" # Management scope network address

$nodes = @(
 @{ Hostname = "azlocal-node01"; MgmtIP = "192.168.203.11"; MgmtMAC = "AA-BB-CC-DD-EE-01"; ServiceTag = "ABCDE01" },
 @{ Hostname = "azlocal-node02"; MgmtIP = "192.168.203.12"; MgmtMAC = "AA-BB-CC-DD-EE-02"; ServiceTag = "ABCDE02" },
 @{ Hostname = "azlocal-node03"; MgmtIP = "192.168.203.13"; MgmtMAC = "AA-BB-CC-DD-EE-03"; ServiceTag = "ABCDE03" },
 @{ Hostname = "azlocal-node04"; MgmtIP = "192.168.203.14"; MgmtMAC = "AA-BB-CC-DD-EE-04"; ServiceTag = "ABCDE04" }
)
#endregion

foreach ($node in $nodes) {
 $resName = "$($node.Hostname)-mgmt"
 $resDesc = "Mgmt NIC for $($node.Hostname) (ST: $($node.ServiceTag))"
 Write-Host "Creating: $resName -> $($node.MgmtIP)" -ForegroundColor Yellow
 Add-DhcpServerv4Reservation `
 -ComputerName $DHCPServer `
 -ScopeId $MgmtScopeId `
 -IPAddress $node.MgmtIP `
 -ClientId $node.MgmtMAC `
 -Name $resName `
 -Description $resDesc
 Write-Host " Created" -ForegroundColor Green
}

Write-Host "Done." -ForegroundColor Green

Customer-Managed DHCP

When to use: DHCP infrastructure is managed by the customer network team

Information to Provide to Customer

Extract and provide the following from variables.yml:

Field	variables.yml Path	Example
Management NIC MAC	nodes.<name>.macs.onboard_port1	C4:CB:E1:F9:AF:E4
Planned management IP	nodes.<name>.management_ip	192.168.203.11
Reservation name	Derived: <hostname>-mgmt	azlocal-node01-mgmt
Description	Derived	Mgmt NIC for azlocal-node01 (ST: ABCDE01)
DHCP scope	network.vlans.management.cidr	192.168.203.0/24

Coordination Steps

1. Extract node data from variables.yml
2. Submit request to customer network team with the table above
3. Confirm VLAN and DHCP scope with network team
4. Obtain confirmation that reservations have been created
5. Validate (see below)

Validation

• Customer confirms all reservations created
• IP addresses match variables.yml: nodes.<name>.management_ip
• MAC addresses match variables.yml: nodes.<name>.macs.onboard_port1
• Reservation names follow convention: <hostname>-mgmt

---

Validation Checklist

# Windows DHCP — List management NIC reservations
$config = Get-Content ".\config\variables.yml" -Raw | ConvertFrom-Yaml
$MgmtScopeId = ($config.network.vlans.management.cidr -split '/')[0]
$DHCPServer = $config.network.vlans.management.dhcp.server

Get-DhcpServerv4Reservation -ComputerName $DHCPServer -ScopeId $MgmtScopeId |
 Format-Table -Property Name, IPAddress, ClientId, Description -AutoSize

Expected Output:

Name IPAddress ClientId Description
---- --------- -------- -----------
azlocal-node01-mgmt 192.168.203.11 c4-cb-e1-f9-af-e4 Mgmt NIC for azlocal-node01 (ST: 8T6GDB4)
azlocal-node02-mgmt 192.168.203.12 c4-cb-e1-f9-ca-2e Mgmt NIC for azlocal-node02 (ST: 9T6GDB4)

• DHCP reservation created for every node (one per node)
• IP addresses match nodes.<name>.management_ip in variables.yml
• MAC addresses match nodes.<name>.macs.onboard_port1 in variables.yml
• Reservation names follow convention: <hostname>-mgmt
• Reservation descriptions include hostname and service tag
• All reservations in the correct management DHCP scope

---

Troubleshooting

Issue	Cause	Resolution
DhcpServer module not found	RSAT not installed	Install-WindowsFeature RSAT-DHCP or run directly on DHCP server
Duplicate reservation	Reservation already exists	Remove existing: Remove-DhcpServerv4Reservation then re-add
Scope not found	Wrong scope ID	Verify: Get-DhcpServerv4Scope -ComputerName $DHCPServer
Access denied	Insufficient rights	Run as DHCP Administrator role member
MAC address format error	Incorrect format	Use format: AA-BB-CC-DD-EE-FF (hyphens, not colons)
FortiGate SSH access denied	SSH not enabled or wrong credentials	Enable SSH on FortiGate admin interface
DHCP server unreachable	Network connectivity	Verify management server can reach DHCP server

---

Navigation

← Task 02: Hardware Discovery	↑ Phase 01: Hardware Provisioning	Task 04: BIOS/iDRAC Validation →

---

Version Control

Version	Date	Author	Changes
1.0	2026-01-31	Azure Local Cloud Azure Local Cloudnology	Initial document
1.1	2026-03-04	Azure Local Cloud Azure Local Cloudnology	Fix tab labels, script paths, variable references, standards alignment