Hi,

a customer had the issue that an virtual machine gets down frequently. An ipconfig reports a IP Address of the “Automatic Private IP Addressing” range (169.254.x.x).

An Eventlog entry with ID is also written.

PS D:\> Get-EventLog -LogName System  -EntryType Error | ?{$_.EventID -eq 4199 } | fl *


EventID            : 4199
MachineName        : myServer.myDomain.org
Data               : {0, 0, 0, 0...}
Index              : 705401
Category           : (0)
CategoryNumber     : 0
EntryType          : Error
Message            : The system detected an address conflict for IP address 0.0.0.0 with the system
                     having network hardware address 55-aa-ee-cc-11-00. Network operations on this system may
                     be disrupted as a result.
Source             : Tcpip
ReplacementStrings : {, 0.0.0.0, 55-aa-ee-cc-11-00}
InstanceId         : 3221229671
TimeGenerated      : 07.08.2022 12:15:41
TimeWritten        : 07.08.2022 12:15:41
UserName           :
Site               :
Container          :

This could happen when ArpProxy Service replies incorrectly to all ARP requests or the physical switch has gratuitous ARPs enabled.

The solution is to disable gratuitous ARP.

Start a cmd.exe shell with administrator permissions:

D:\> reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /v ArpRetryCount /d 0 /t REG_DWORD /f

Check and reboot the system

D:\> reg query HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /v ArpRetryCount

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
    ArpRetryCount    REG_DWORD    0x0
D:\> shutdown /t 0 /r

Michael