Starting with NRSW 4.5.0.100  we introduce an config parameter to define the MAC Adress of an Ethernet Interface via cli  / config 

Example: 

<code>
cli set network.lan.2.mac=00:11:22:33:44:CC" "network.lan.3.mac=00:11:22:33:44:DD" 
</code>


This option is not visible in the Web Interface