Several running Windows 2008 R2 VM suddenly lost network connection. When this happen, i can ping the VM's IP address, but fail to connect the VM via RDP, IPCONFIG does not show any virtual NIC information, disable/enable eht NIC in the VM does not change the state, but reboot the VM will resume the connection. What is the problem ?
The ESXi version ESXi 5.5 Patch 5 re-release(build-2718055), the virtual NIC type is Vmxnet3.