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Turn off TCP checksum offload

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linux-howto

http://stackoverflow.com – I am programming a linux networking driver. It is almost done. When I ping between 2 PC, everything is perfect. And then I try to use some TCP/UDP protocols, and the receiver never reply. I used wireshark to see what happens there, and I found all the TCP packets have incorrect checksum. It is said the wrong checksum is caused by TCP checksum offload. I tried to turn it off with ethtool. When I use sudo ethtool -K uwn0 tx off, it replies me Cannot get device rx-checksumming settings: Operation not supported Cannot get device tx-checksumming settings: Operation not supported Cannot get device (HowTos)