I have a design that has AXI Ethernet subsystem and Ethernet DMA.
I have a custom packet filter module that is plugged between the Ethernet subsystem and the DMA.
However, the LWIP has stopped working. It stalls at this line:
TCP packets sent to port 6001 will be echoed back.
The same thing happens if I plug a very basic custom IP that forwards in and out through FIFO, or if I plug in the ChipScope debugger to the axis_rxd and axis_rxs bus to study Ethernet packets.
This is a known issue.
With ChipScope or other custom IPs attached on the AXI4 Stream interface, some properties are not getting exported properly by the driver/lwIP to the xparameters.h and some _g.c files.
Attached is the driver fix. You will need to set a custom repository in SDK and rebuild the SDK lwIP application.