You can find the MAC address for LAN1/eth0 (not the BMC MAC) via the SuperMicro IPMI interface by running the following command:
$ ipmitool -U $IPMI_USER -P $IPMI_PASS -H $IPMI_HOST raw 0x30 0x21 | tail -c 18
The eth0 MAC address will be output in this format:
00 25 90 f0 be ef
@GA114: well, you could get it from your ARP table, but yeah, lan print will show a bunch of stuff including MAC