Fig. 12 Rockwell Bootp/Dhcp Server 2.3 - Mac Address - Beckhoff BK9105 Documentation

Parametrization and commissioning
Take note that the dip switches 1 to 8 no longer hold any addressing capabilities.
The MAC Address begins with 00-01-05-xx-xx-xx (see under the BK9105 to find the MAC address).
Fig. 12: Rockwell BOOTP/DHCP Server 2.3 - MAC address
After a successful addressing you can disable the BOOTP addressing.
28 Version: 2.0.0 BK9055 and BK9105