DHCP scope utilization report

Good For

• DHCP exhaustion triage
• subnet planning
• IPAM cleanup
• branch office review
• network migration prep

How to Use It

1. Start with the DHCP server or failover pair tied to the affected site, VLAN, or subnet.
2. Capture every IPv4 scope, state, range, and utilization percentage.
3. For hot scopes, collect lease evidence so long-lived clients, reservations, and stale names can be reviewed.
4. Compare utilization against planned subnet size, exclusions, reservations, and recent network changes.
5. Flag exhausted scopes, disabled scopes, high reservation density, and stale lease cleanup candidates.
6. Export findings for network owner review before expanding ranges or changing lease duration.

Execution Modes

• local
• remote-single-host

Inputs and Outputs

Inputs

• DHCP server name
• scope review threshold
• known site or VLAN mapping

Outputs

• verbose-console
• csv

Command Starter

Safe to run: read-only

# ---------------------------------------------------------------------
# Operator inputs
# ---------------------------------------------------------------------
$DhcpServer = 'dhcp01.contoso.com'
$ReviewThreshold = 80
$ScopeOutput = '.\dhcp-scope-utilization.csv'
$LeaseOutput = '.\dhcp-hot-scope-leases.csv'

# ---------------------------------------------------------------------
# Scope utilization summary
# ---------------------------------------------------------------------
$ScopeStats = Get-DhcpServerv4ScopeStatistics -ComputerName $DhcpServer |
    Select-Object ScopeId, AddressesFree, AddressesInUse, PercentageInUse

$ScopeStats | Export-Csv -Path $ScopeOutput -NoTypeInformation -Encoding UTF8

# ---------------------------------------------------------------------
# Lease detail only for scopes above the review threshold
# ---------------------------------------------------------------------
$HotScopeLeases = foreach ($Scope in $ScopeStats | Where-Object { $_.PercentageInUse -ge $ReviewThreshold }) {
    Get-DhcpServerv4Lease -ComputerName $DhcpServer -ScopeId $Scope.ScopeId |
        Select-Object @{Name='ScopeId';Expression={$Scope.ScopeId}}, IPAddress, HostName, ClientId, AddressState, LeaseExpiryTime
}

$HotScopeLeases | Export-Csv -Path $LeaseOutput -NoTypeInformation -Encoding UTF8
$ScopeStats | Sort-Object PercentageInUse -Descending | Format-Table -AutoSize

Validation

• Every reviewed DHCP scope has utilization evidence or an access/error note.
• Scopes above the review threshold have lease evidence and a proposed owner action.
• Any later DHCP change is validated by rerunning the utilization report.

Reporting

• export DHCP scope utilization and hot-scope lease details to CSV
• group high-utilization scopes by site, VLAN, and owning network team
• promote repeated use into DHCP capacity planning evidence

Safety Notes

• This report is read-only and should not add scopes, delete leases, or change lease duration.
• Do not expand ranges or edit exclusions without network owner approval and change tracking.