Unable to power on VM due to MAC Address issues

Products

• VMware vSphere ESXi

Issue/Introduction

Attempting to power on a Virtual machine fails and reports an error with the MAC address

Environment

VMware vSphere ESXi

Cause

The MAC address specified for the virtual machine's network adapter conflicts with MAC addresses that VMware reserves for its own use. VMware typically reserves ranges of MAC addresses to avoid conflicts with other devices on the network.

Resolution

• Locate the VM logs and determine which ethernet card is the affected one

Example:

YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - Power on failure messages: Impermissible static Ethernet address: 'XX:XX:XX:XX:XX:XX'.
YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - It conflicts with VMware reserved MACs.
YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - Invalid MAC address specified.
YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - Could not set up 'macAddress' for 'ethernet1'.
YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - Module 'DevicePowerOn' power on failed.
YYYY-MM-DDTHH:MM:SS.353Z In(05)+ vmx - Failed to start the virtual machine.

• Create a backup file of the vmx
• Edit the vmx and add the line: ethernetX.checkMACAddress = "false"

Reference: 

ethernet1.checkMACAddress = "FALSE"

• Reload the vmx. Reference: Reloading a vmx file without removing the virtual machine from inventory
• Power On the VM.