tcp checksum incorrect for ack packet
<p>I am working on raw sockets. I am first sending a SYN packet to a server. This packet seems correct on wireshark and does not generate any ip or tcp checksum warning.
I am receiving the SYN ACK from the server as well. 
Now when I am trying to ACK back to the server. The wireshark reports that my tcp checksum is incorrect. I am using the same func to calc the checksum. What may be the issue?</p>