Virtual Machine Loses Network Connection After Restart

Issue:

Virtual machines (VM) when soft rebooted lose their network connection if a static ip address is specified for the VM.  If the VM is restarted a second time, then the network connection starts working again.  If the network connection is disabled and re-enabled, then the network connection starts working again.  The message in the event log is related to a duplicate IP address error, but there are no other machines or devices using that IP address.

The VM is restarting so fast that the network switch is telling the VM that the static IP address specified is already taken after a warm reboot. This issue occurs when the Cisco switch has gratuitous ARPs enabled or the ArpProxySvc replied to all ARP requests incorrectly.

Solution:

Add the ArpRetryCount = 0 in the registry of all virtual machines.  I don’t recommend disabling gratuitous arps on any switches.

 

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
"ArpRetryCount"=dword:00000000

 

Resources:

http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/8021x/116529-problemsolution-product-00.html

https://technet.microsoft.com/en-us/library/cc957526.aspx

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1028373

 

https://support.microsoft.com/en-us/kb/219374

https://social.technet.microsoft.com/Forums/office/en-US/d7bda315-6366-4e0a-bdcf-dc875ff6963e/win-2008-r2-servers-will-not-connect-to-network-says-duplicate-ip?forum=windowsserver2008r2networking

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