tcp checksum and tcp offloading

Posted by scatman on Stack Overflow See other posts from Stack Overflow or by scatman
Published on 2010-03-23T06:19:49Z Indexed on 2010/03/23 6:23 UTC
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raw-sockets

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tcp

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checksum

i am using raw sockets to create my own socket. i need to set the tcp_checksum.
i have tried a lot of references but all are not working (i am using wireshark for testing).
could you help me please.
by the way, i read somewhere that if you set tcp_checksum=0. then the hardware will calculate the checksum automatically for you. is this true? i tried it, but in wireshark the tcp_checksum gives a value of 0X000 and says tcp offload. i also read about tcp offloading, and didn't understand, is it only that wireshark is cannot check an offloaded tcp checksum, but there is a correct one??

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