Resolve Windows DHCP Scope Exhaustion and No-Address Errors

Before you begin

Applicable to supported Windows Server/client environments where the named role or feature is installed. Run read-only checks first from an elevated PowerShell or Command Prompt as appropriate. Replace example hostnames, domain names, addresses, ports and paths with values from the affected environment. Record the exact error, timestamp, OS build and scope of impact.

Production safety: obtain change approval and a verified backup before modifying AD DS, DNS, DHCP, firewall, IIS, storage or Hyper-V configuration. Ensure console/out-of-band access before network or remote-access changes.

Symptoms and likely root cause

New clients fail to obtain leases while existing devices continue working; the DHCP scope may be full.

Scope utilisation, stale leases, BAD_ADDRESS entries, static devices inside the pool, reservations, lease duration or relay design.

Diagnostic commands

Get-DhcpServerv4Scope -ComputerName DHCP01
Get-DhcpServerv4ScopeStatistics -ComputerName DHCP01
Get-DhcpServerv4Lease -ComputerName DHCP01 -ScopeId 10.20.30.0
Get-DhcpServerv4ExclusionRange -ComputerName DHCP01 -ScopeId 10.20.30.0
Get-DhcpServerv4Reservation -ComputerName DHCP01 -ScopeId 10.20.30.0

Run the commands in order and save the complete output. The commands above are intended to establish the failing layer before a configuration change is attempted.

How to interpret the results

Scope statistics should show free addresses and percentage in use. Review lease expiry, client name, MAC and BAD_ADDRESS state. Compare static IP inventory and reservations against the dynamic pool.

Practical correction

Reclaim only confirmed obsolete leases, correct exclusions/reservations or redesign the subnet/VLAN if capacity is genuinely insufficient. Do not widen a scope across another subnet or include gateway/server/printer static addresses. Verify relay/IP helper for remote VLANs.

Make one change at a time. Re-run the failed diagnostic after each change so the cause-and-effect relationship is clear.

Fallback and recovery

Export DHCP configuration before changing range/options. Restore the previous scope range and options if clients receive the wrong mask, gateway or DNS. Test renewals on a normal endpoint, not a remote server whose management depends on DHCP.

Verification checklist

Success: test clients obtain an address in the correct subnet with correct gateway, DNS and lease duration; no duplicate or BAD_ADDRESS events recur.

• Repeat the original failing operation from the affected client/user or service.
• Test from a second approved endpoint or subnet where relevant.
• Review the relevant event log/IIS log after the fix.
• Record the change, actual result and any remaining limitation.

Frequently asked question

Should I just increase the subnet mask? No. Subnet, VLAN, routing and reservations must all support the change.

Official technical reference

Microsoft Learn — troubleshoot dhcp guidance

Use the official documentation for exact version support, prerequisites and any procedure that differs between Windows Server releases.

Technician field note

This runbook describes a controlled diagnostic path; it is not a universal guarantee that every environment has the same cause. If evidence does not match the expected result, stop and investigate rather than applying unrelated fixes. Do not mark the incident resolved until the original symptom is verified as cleared.