When multiple devices with the same mac id are connected to the network, eth0 fails.
Each board should have a unique MAC address to avoid conflict. You might need to manually configure unique MAC addresses for each board.
To resolve this, below commands are executed before bringing up eth0:
ifconfig eth0 down
ifconfig eth0 hw ether XX:XX:XX:XX:XX:XX up
udhcpc -i eth0
ifconfig
Replace XX:XX:XX:XX:XX:XX with a unique MAC address for each board.
You can also stop in u-boot and run “setenv ethaddr XX:XX:XX:XX:XX:XX”, then save the boot arguments using saveenv and powercycle the board.
For further inquiries, please get in touch with mktg@iwave-global.com
Please find the detailed G30M product information in the below link,