Informational

The vmk0 is a virtual interface and a MAC address is generated for it when it is created. When the ESXi template is cloned the vmknic and its configuration (Name, MAC, MTU, and IP settings) are also cloned. Accessing ESXi Shell and running esxcfg-vmknic -l will list the configured vmknics and the configurations (including the MAC) of each.

Enable ssh on the host you want to change:

esxcfg-nics -l lists your physical nics on the machine, with their correct macs.
esxcfg-vmknic -l lists the management nics, which are the ones you want to change.

Copy the good macs, then edit /etc/vmware/esx.conf, and scroll down.
Just replace the macs there.

Save the file, then type “dcui” to get to the console screen, login, then simply restart the management network.

Ctrl-C to go back to the shell, and check again esxcfg-nics -l and esxcfg-vmknic -l.

They should be the same.