NDIS IP fragmentation and TCP checksum

NTDEV
1

Hi,

I am facing problem with TCP checksum calculation failure by the NIC (task
offloaded) for IP fragmented packets in Windows 2000. The miniport driver
has been implemented to task offload TCP checksum to the NIC. So is there a
way in which I can inform the OS / TCPIP layer to recalculate the checksum
on a per packet basis whenever the packet is a fragmented one and the NIC
has failed the checksum calculation.

thanks in advance,
Srihari

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2

Perhaps setting the NDIS_PACKET protocol type to NDIS_PROTOCOL_ID_DEFAULT
will convince TCP/IP to calculate the checksum.

Good luck,

Thomas F. Divine

PCAUSA - Toolkits & Resources For Network Software Developers
NDIS Protocol - NDIS Intermediate - TDI Client
http: - http:

----- Original Message -----
From:
To: “NT Developers Interest List”
Sent: Wednesday, October 03, 2001 10:42 AM
Subject: [ntdev] NDIS IP fragmentation and TCP checksum

> Hi,
>
> I am facing problem with TCP checksum calculation failure by the NIC (task
> offloaded) for IP fragmented packets in Windows 2000. The miniport driver
> has been implemented to task offload TCP checksum to the NIC. So is there
a
> way in which I can inform the OS / TCPIP layer to recalculate the checksum
> on a per packet basis whenever the packet is a fragmented one and the NIC
> has failed the checksum calculation.
>
> thanks in advance,
> Srihari

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