Problem of receiving TCP packets on Virtual adapter

Hi,
I am porting IM driver on WM5.0. I have created a virtual miniport
with lower metric value so that upper layer application bind with that
VA. So all the packets (TCP/UDP) are coming to that VA with IP and MAC
of that VA. The IM then spoof the IP and MAC and put the original
miniport IP and MAC and send the packet to the original
miniport(TNETWLN1). When original miniport receive the packet IM change
the IP and MAC of original to the VA and indicate to the upper layer
protocol. This works fine in case of UDP packets but TCP packets are
not accepted by TCP/IP stack. I check the MAC, IP, Port and CheckSum of
TCP packet after spoofing it back. I also checked the MP binding it is
fine too. Here what can be the problem. Somebody has find this kind of
problem ever. Any kind of help is appreciated.

Thanks
Rajat

<> wrote in message
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> Hi,
> I am porting IM driver on WM5.0. I have created a virtual miniport
> with lower metric value so that upper layer application bind with that
> VA. So all the packets (TCP/UDP) are coming to that VA with IP and MAC
> of that VA. The IM then spoof the IP and MAC and put the original
> miniport IP and MAC and send the packet to the original
> miniport(TNETWLN1). When original miniport receive the packet IM change
> the IP and MAC of original to the VA and indicate to the upper layer
> protocol. This works fine in case of UDP packets but TCP packets are
> not accepted by TCP/IP stack. I check the MAC, IP, Port and CheckSum of
> TCP packet after spoofing it back. I also checked the MP binding it is
> fine too. Here what can be the problem. Somebody has find this kind of
> problem ever. Any kind of help is appreciated.
>
> Thanks
> Rajat
>
Do you insure that the first NDIS buffer of the receive packet contains the
MAC ehader plus Lookahead bytes of the Ethernet payload?

Thomas F. Divine