Not really possible, becase all traffic to the ISP will come from a single
MAC address, even if it originated on a different PC. The routed packets
will be wrapped by the gateway machine and appear as it's own requests.

You can try and limit NIC installation but even that won't work because a
single NIC can be multi-homed.

If someone really wants to share, they'll just get a hardware router and
clone the host PC MAC address.

Remember, the ISP is providing internet for a single CONNECTION, not a
single COMPUTER.

"Ganesh J. Acharya"  wrote
in message
news:1a8444d1.0407070955.5ac635e0{at}posting.google.com...
> Shree Ganesha
>
>
> Dear Friends,
>
> Pls tell me what shd I be doing in order to block registered users of
> any ISP from routing INTERNET Connection through a windows client.
>
> Many of ISP user pay only for one internet connection and the route
> the internet connection to other computers.
>
> I am here to write a program a small module to be installed on the
> client computer that will disallow the following
>
> 1.) Internet Sharing (ISHARE)
> 2.) The use of any kind of proxy servers on the client machine
>
> Soln I think can solve my problem...
>
> 1.) I will register the mac address of the lancard along with my
> clients database and then disallow the presence of any other lan card
> on the same machine.
>
> Problem: The client will not be able to use file sharing and printer
> sharing due to these kind of restrictions.
>
> Kindly suggest a walk around.....
>
> 2.) I will check the ports open for the other lan cards and block them
> during the session for which my lancard is running
>
> Pls tell me the probable solns
>
> Pls also discuss the probable problms
>
> Best Regards
> Ganesh J. Acharya
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