Windows 2008 virtual machine loses network connectivity

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Windows 2008 virtual machine loses network access.
• Virtual machine does not respond to ping.
• cannot ping the default gateway of the virtual machine.
• Running the arp -a command at the Windows command prompt shows an invalid Address Resolution Protocol (ARP) entry for the default gateway.

Environment

VMware vSphere ESXi 5.1
VMware vSphere ESXi 5.5
VMware ESX 4.1.x
VMware vSphere ESXi 5.0
VMware ESXi 4.1.x Embedded
VMware ESXi 4.1.x Installable

Cause

In Windows 2008, gratuitous ARP is handled differently and as a result, the ARP entry may become invalid after a virtual machine migration using vMotion.

Resolution

To resolve this issue, apply the hotfix in the Microsoft Knowledge Base article 2582281.

 

Note: The preceding link was correct as of November 26, 2013. If you find the link is broken, provide feedback and a VMware employee will update the link.

 

Note: Though this hotfix is not specific to these symptoms, it pertains to the same root cause and therefore, resolves this issue.

 

Alternatively, to work around this issue, add a static ARP.

 

To add a static ARP, run one of these commands from the Windows command prompt:

• arp -s default_gateway_IP_address MAC_address
  
  For example:
  
  arp -s xx.xx.xx.xx 00-11-22-aa-bb-cc
   
• netsh interface ip add neighbors network_card_name default_gateway_IP_address MAC_address
  
  For example:
  
  netsh interface ip add neighbors network_card_name xx.xx.xx.xx 00-11-22-aa-bb-cc

Note: Static ARP entries are valid only until your computer is restarted. To make static ARP cache entries persistent, you can add ARP commands to a batch file that runs at system startup.

Additional Information

Windows 2008 の仮想マシンがネットワークに接続できない