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<DIV><FONT size=2>Hi Quinton.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Some boards do TCP offloading, i.e. they compute
the checksum on the board. So you were right. </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>This ethereal FAQ provides some more details about
it</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2><A
href="http://www.ethereal.com/faq.html#q5.14">http://www.ethereal.com/faq.html#q5.14</A></FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Have a nice day</FONT></DIV>
<DIV><FONT size=2>GV</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=quintont@deltacompsys.com
href="mailto:quintont@deltacompsys.com">Quinton Tormanen</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=winpcap-users@winpcap.org
href="mailto:winpcap-users@winpcap.org">winpcap-users@winpcap.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, June 03, 2005 7:54 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [Winpcap-users] Out-going TCP/IP
checksums</DIV>
<DIV><BR></DIV><!-- Converted from text/rtf format -->
<P><FONT face=Arial size=2>I am using the direct Packet interface (e.g.
PacketReceivePacket), and I have found that the vast majority of TCP/IP
packets being sent out by the PC running packet show up with invalid TCP
header checksums. I am running on Windows 2K, SP4 and the interface I am
monitoring is a 3COM Ethernet card.</FONT></P>
<P><FONT face=Arial size=2>I am assuming that the invalid checksums are not
actually getting out onto the wire, but instead has something to do with when
the checksums are computed. Can anyone confirm that this is the
case?</FONT></P>
<P><FONT face=Arial size=2>Quinton Tormanen</FONT> <BR><FONT face=Arial
size=2>Software Engineer</FONT> <BR><FONT face=Arial size=2>Delta Computer
Systems, Inc.</FONT> <BR><A href="http://www.deltacompsys.com"><U><FONT
face=Arial color=#0000ff size=2>http://www.deltacompsys.com</FONT></U></A>
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