Actually, you can probably expect that the ping -s with jumbo frames to fail, since the FPGA stack is very limited and most likely hasn’t implemented ICMP for jumbo frames.
However, the limitation of 8000 seems to be an artificial limit of the UHD code, as it I have been able to demonstrate it can send > 8000, but not at my requested value due to the way the driver is written. You can see in the packet trace (if you do a tcpdump) is sends larger than 8000. See “static const size_t DATA_FRAME_MAX_SIZE = 8000; // CHDR packet size in bytes” in x300_defaults.hpp and what appears to be some bad logic in determine_max_frame_size() (setting packet size to min(tx,rx)).\ I hacked the code and have seen the Tx >= 8136, but don’t understand it enough yet. You might also need to reach out to the FPGA team to actually see what the limitation is or is not. Documentation says to set MTU to 9000, but UHD driver has some issues in implementation.
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