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We have created a socket program (using winsock control) in Visual
Basic under windows 2000 platform . And using this application we are
transfering data from a PC to our custom Board through 1000 base T
Fibre Optic Ethernet card...

While transferiing data from Pc to the Board .. we are getting IP
Header Checksum Error

Ethernet II:
Header checksum 0X0000: [incorrect,should be 0Xf2a0]

What is the cause of this error.. does any changes need to be made in
the VB application to clear this error.. or any compatiblity problem

can any one help me to sort out this problem?




devi

In article < .com>,
<> wrote:
>We have created a socket program (using winsock control) in Visual
>Basic under windows 2000 platform . And using this application we are
>transfering data from a PC to our custom Board through 1000 base T
>Fibre Optic Ethernet card...

Which component in this configuration was made by Cisco?


>While transferiing data from Pc to the Board .. we are getting IP
>Header Checksum Error

>Ethernet II:
>Header checksum 0X0000: [incorrect,should be 0Xf2a0]

>What is the cause of this error..

What is reporting this problem? If you are sniffing traffic on the
same system that is producing the traffic, then you might be
encountering a common issue: if the IP driver has been set to
offload checksum calculations to the ethernet card, then packets that
gets sniffed before being submitted to the cards will not have had
their checksum updated yet.

[no1]

Hey I know this is a bit of an ancient thread but I noticed a similar problem to this I was having (well not really a problem but it was confusing me for a while) with an onboard ASUS Atheros NIC.

Whenever capturing with WinPcap/Wireshark and I had task offload set to yes in my NIC driver advanced options it would always make Wireshark report that every sent TCP packet from this machine had an incorrect header checksum (0x0000). Switching task offload off seemed to make it use the correct checksum.

Thanks for pointing me in the right direction.