Hello friends, I need to know how to restore the MAC address of the routers, I passed a backup that I had with some basic configuration to several devices and I am realizing that the MAC address of the original device is copied in the other 3 in which I restore, the problem is that my ISP cannot assign me a fixed IP since the MACs are repeated in other devices, I appreciate any help you can give me … : 
/interface ethernet reset-mac-address ether1,ether2,...