Jumbo Frames 1-Way Fragmentation

[rickatnight11]

I have two Windows 7 machines with Gigabit NICs connected to a Gigabit switch that supports up to 9k Jumbo Frames. I configured both NICs to use 9k Jumbo Frames, restarted both machines, but when I run a ping with the "-f -l" flags set to test Jumbo Frames, I get the following result:

Desktop --> HTPC: I can successfully ping with packets up to 8872 in size, as expected
HTPC --> Desktop: Any packets over the normal 1472 size give me the "Packet needs tobe fragmented but DF set" message

What gives?

 

[rickatnight11]

I performed a WireShark capture on the HTPC, and it looks like the 8972-length packets are being fragmented, so I guess that means Jumbo frames aren't working in either direction.