Triple Speed Ethernet (1000-Mbps) : transmit Jumbo frames?

Hello all.

I was working on a project with Triple-Speed Ethernet IP Core, and I'm having a bit of trouble understanding how to send jumbo frames. I built the system on Qsys with Triple Speed Ethernet (10/100/1000-Mbps) with two SGDMA modules for packet generation/extraction.

The Triple-Speed Ethernet IP Core User Guide shows that, on 10.5 Using Jumbo Frames, frm_length[15:0] (Dword offset 0x05) register should be set to 9600 (which would be 0x2580).

So I software-initialized with *(tse_base+0x05) = *(tse_base+0x05) | 0x2580;
Then used API Function alt_avalon_sgdma_construct_mem_to_stream_desc() with byte length 16+9600.

I can see that the packet is being sent (looking at the LED on my FPGA board), but nothing being received on Host PC.
Tried loopback receive too but nothing showing up.

Is this the right way to send Jumbo Packets with Triple-Speed Ethernet? I will need to check problems with receive, but I wanted to make sure there isn't a problem with transmit.

Thank you.