Hello Leon,
you can view the MAC addresses upfront the installation/configuration within the Service Assistant GUI of each nodecanister.
The nodecanisters default ip addresses for accessing the Service Assistant GUI are:
Canister 1 (left) port1 (left) - 192.168.70.121
Camnister 2 (right) port 1 (left) - 192.168.70.122
For the login you have to use the password of user "superuser".