Hi @JayCao ,
RT1176 boot ROM doesn't support ENET. So at least there must be a bootloader which can access ENET and an application.
You can refer to the opensource bootloader demo in SDK or the SBL&SFW project.
These two example are real OTA. I don't know how to download application to system by ENET without OTA.
Maybe you can have something like a debug probe which can download code from ENET and download to RT1176 via UART/USB/JTAG?
Regards,
Jing