IoT Router Board Mini + Compute Module 5

Hello,

Also it is not mentionned to be compatible and wiki page does not get updates, I tried to run the IoT Router Board Mini with a Compute Module 5.

I managed to generate a custom image starting the working Raspberry Pi5 version and added the missing modules for the RTL8111 chip.

Now I have a fully booting image and both NICs are detected. But for a reason I don't understand, I can not get a PC to communicate with the router.

Eth0 has 192.168.1.1 as a static IP address, but the attached computer seems not to get an IP allocated from DHCP server. Even if I set the computer's IP address to 192.168.1.2 manually, I can not get poth to communicate or ping.

There is no public schematic of the board so I can not troubleshoot. Looking at the CM4 and CM5 differences regarding pinout, I noticed the following pin functions changes :  Fan_Tacho (pin 16) replaces Ethernet_SYNC_IN and Fan_PWM (pin 19) replaces Ethernet_nLED1.

I don't know if those modifications can explain the communication issue I'm facing.

The same image works fine on Raspberry Pi5.

If anyone have suggestions, I'm all ears!

Thanks