CubeIDE comes with support for LwIP as the tcp/ip stack. It doesn't look like LwIP has gotten updates since 2018. Is it stable or abandoned? It's hard to tell one way or the other (other then complaints from people that have used it before).
LwIP has two modes of use, with an RTOS and without. ST hooked LwIP in with FreeRTOS and there are a few simple samples to pull from.
The F and H 7 processors have fun issues(?) when doing DMA with the ethernet controller. You should run into multiple discussions on this forum regarding caching of the rx and tx buffers and descriptors. Look at the LwIP_HTTP_Server_Netconn_RTOS example (currently broken for that processor) in the .ld file. There are 4 extra memory regions defined. Elsewhere in the code there are the buffers and descriptors that get pushed into these regions, and the memory management unit is used to set the caching appropriately. The memory calculations aren't quite done right, but it's close enough for hobby stuff.
If you generate a program basis using CubeMX and choose a 767ZI processor, ethernet, LwIP, FreeRTOS, set your timer to 6, and choose all of the correct basic options, you still need to munge the .ld file, push the buffers and descriptors into the sections, and set up the MMU. That is not done for you in a generated project.
If you find other working examples, let everybody know. The LwIP documentation is mostly about how LwIP works internally, how to set up your tools to develop LwIP, and how to update the internal documentation. Apparently LwIP has no users, just developers. I think that is where FreeRTOS and their TCP/IP stack may be better, they assume that someone may actually have to use the code at some point, not just generate pull requests.
FreeRTOS has their own tcp/ip stack, I'm not sure what that says about their feelings about LwIP.
