False duplicate IP address detected on Microsoft Windows Vista and later virtual machines on ESX/ESXi when using Cisco devices on the environment / or firewall ASA (1028373)

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.
    Open the Registry editor.
        In Windows XP to Windows Server 2003 - Click Start > Run, type regedit, and click OK.
        In Windows 7 and Current - 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. 

Alternatively, you can disable gratuitous ARP on the physical switch.

For example:

To disable gratuitous ARP in Cisco IOS, run this command:

# no ip gratuitous-arps

To disable gratuitous ARP in ASA firewall, run this command:

# sysopt noproxyarp inside