Symptoms:

• A virtual machine loses network connectivity after performing a vMotion.
• When you use tcpdump to analyze packet traffic, you see that a RARP request is not sent after the virtual machine has been moved via vMotion to the destination host.
• If you set the Load Balancing policy in the vSwitch properties to Notify Switches, the RARP request is sent after performing a vMotion.

VMware ESXi 4.0.x Installable
VMware ESX 4.1.x
VMware vCenter Server 5.1.x
VMware vSphere ESXi 5.5
VMware vSphere ESXi 6.0
VMware ESX Server 3.5.x
VMware ESXi 4.1.x Embedded
VMware VirtualCenter 2.5.x
VMware vCenter Server 6.0.x
VMware vSphere ESXi 5.1
VMware vCenter Server 5.5.x
VMware vCenter Server 4.0.x
VMware ESXi 3.5.x Embedded
VMware vSphere ESXi 5.0
VMware vCenter Server 4.1.x
VMware ESXi 4.0.x Embedded
VMware vCenter Server 6.5.x
VMware ESX 4.0.x
VMware vCenter Server 5.0.x
VMware vSphere ESXi 6.5
VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Installable

To resolve this issue, enable switch notification by setting the Notify Switches option to Yes in the Load Balancing and Failover Policy.

If setting the Notify Switches option to Yes does not resolve the issue:

• Ensure the virtual machine is on the proper VLAN ID after vMotion by checking the port configuration of the vSwitch and physical switch.
• Check the VLAN configuration on the vSwitch.
• Check the subnets assigned to VLANs.
• Check the physical switch ports for proper VLAN configuration.

For more information on troubleshooting steps, see Troubleshooting virtual machine network connection issues (1003893).

For more information on VLAN configuration, see VLAN Configuration on Virtual Switch, Physical Switch, and Virtual Machines (1003806).

For more information about port group configuration, see the vSphere Networking guide.

VLAN configuration on virtual switches, physical switches, and virtual machines
Troubleshooting virtual machine network connection issues
vMotion の後に仮想マシンのネットワーク接続が失われる
执行 vMotion 后虚拟机失去网络连接