False Duplicate IP Address on Microsoft Windows virtual machines on ESXi

Products

VMware vSphere ESXi

Issue/Introduction

You see an APIPA address (169.254.X.X) IP listed as preferred and the static IP listed as a duplicate when you run the command:

ipconfig /all

You may also notice any of the following:

Assigning an IP address, you see a duplicate IP address conflict.
The VM is assigned a 169.254.x.x address.
When you set up the same virtual machine on a virtual switch with no uplink port on it, the IP address is assigned successfully.
When you assign the same IP address to another virtual machine on the same virtual switch, the IP address is assigned successfully.
You might encounter this issue after disconnecting the VM from one vswitch and connecting it to another as part of a vDS migration.
You find that disabling and enabling the interface from the guest OS level resolves the duplicate IP address issue.
If packet captures from the VM are obtained during issue reproduction, you may observe GARP packets in Wireshark originating from a non-VMware source MAC address, which are flagged as "Duplicate IP address detected" for the IP assigned as the static address.

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 was to resolve this for multiple VM's. The commands to disable this are specific to the manufacturer, refer to the manufacture documentation.

Turn off gratuitous ARP in the guest operating system

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

Caution: This procedure modifies the Windows registry. Before making any registry modifications, ensure that you have 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. You can create one for this procedure.
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 used 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. Ensure to refer 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