False Duplicate IP Address on Microsoft Windows virtual machines on ESXi

Products

VMware vSphere ESXi

Issue/Introduction

Running the following command shows an APIPA address (169.254.X.X) IP listed as the preferred IP and the static IP flagged as a duplicate

ipconfig /all

Any of the following may also be observed:

Assigning an IP address, shows a duplicate IP address conflict.
The VM is assigned a 169.254.x.x address.
When a virtual machine is setup on a virtual switch with no uplink port on it, the IP address is assigned successfully.
When the same IP address is assigned to another virtual machine on the same virtual switch, the IP address is assigned successfully.
This issue maybe encountered after disconnecting the VM from one vswitch and connecting it to another as part of a vDS migration.
When disabling and enabling the interface from the guest OS level resolves the duplicate IP address issue.
If packet captures from the VM are taken during issue reproduction, GARP packets may appear in Wireshark originating from a non-VMware source MAC address, and flagged as "Duplicate IP address detected" for the assigned static IP.

Environment

VMware vCenter Server 7.0
VMware vCenter Server 8.0
VMware vSphere ESXi 7.0
VMware vSphere ESXi 8.0

Cause

This issue occurs when the physical switch has gratuitous ARPs enabled or the ArpProxySvc replies to multiple ARP requests incorrectly. This is an issue between Windows and the physical switch. The solution below is performed at the Windows level or on the physical switch.

Resolution

To resolve this issue, use one of these solutions:

Turn off gratuitous ARPs on the physical switch

This is the quickest way to resolve this for multiple VM's. Since the commands to disable this feature vary by manufacturer, please refer to the manufacturer’s documentation for specific instructions.

Turn off gratuitous ARP in the guest operating system

If the issue only occurs on a few VMs, disabling it may be the easiest way to turn off gratuitous ARPs in the guest operating system of each affected VM.

Caution: This procedure modifies the Windows registry. Before making any registry modifications, ensure that there is a current and valid backup of the registry and the virtual machine. For more information on backing up and restoring the registry, see the Microsoft Knowledge Base article 136393.

To turn off gratuitous ARP in the guest operating system:

Shut down the guest operating system and power off the virtual machine.
Change the virtual machine to a network vSwitch with no uplink. A new vSwitch can be created for this if needed .
Power on the virtual machine and log in.
Click Start, type regedit, and click OK.
Locate this registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Click Edit > New, and click DWORD Value.
Type ArpRetryCount.
Right-click the ArpRetryCount registry entry and click Modify.
In the Value box, type 0 and click OK.
Exit the Registry Editor.
Shut down the guest operating system and power off the virtual machine.
Change the virtual machine back to a network vSwitch with the uplink.
Power on the virtual machine.

For more information, see the Microsoft TechNet Article ArpRetryCount.

Additional Information

As of TAC document release 116529, duplicate addressing is identified to cause this issue in some scenarios this is caused by IP device tracking. Duplicate IP Address 0.0.0.0 error message is received by clients that run Microsoft (MS) Windows Vista and later versions.

The primary method to work around the issue is to delay the probe from the switch, so that Windows has time to finish duplicate IP detection. This is not a VMware issue. Be sure to refer to the preceding TAC document for more information before proceeding.

From a SSH or Telnet session to the switch, enter this command to delay the probe:

IP device tracking probe delay 10

Note: This issue can also occur because of gratuitous ARP on an ASA firewall. Run this command to disable gratuitous ARP on an ASA firewall:

sysopt noproxyarp inside