[Winpcap-users] Active sniffing question

[accounts at sandmik.net]

Dear Fellow Developers.

    I am trying to develop a software that does active sniffing, on a 
switched network, in which I poison the ARP cache of two machines to 
intercept their traffic.
I have a problem when one of the machines is the gateway, for some 
reason the reforwarding of packets to the proper destination is still 
missing something. I read about it on the internet and most documents 
say to run the "IP-Forwarding" feature of Windows XP (or 2000) for it to 
work properly. However I do not want to do that, I want to do the job of 
IP-Forwarding myself, I do not want to depend on Windows using this 
task. One software Cain and Abel successful reforward packets, If anyone 
know what I am missing or point me in the right direction, I would 
appreciate it a lot.

    Thanks in advance.