Simple firewall in .net

Question

Hi,

I want to try create a simple firewall which restricts applications from accessing the internet except for applications I allow. Like netlimiter. So it would have to allow internet access for applications that are white listed and drop the connections for the rest. Is this possible with c# or vb.net? If it is possible can you please point me in the right direction.

Thanks

Answer 1

PacketX is a simple little library to sniff packets. Not sure if you can completely block the network though. You'd have to work out a way to disable the network adapter & then make your program appear as the network adapter to forward on the packets as appropriate.

EDIT: My bad. "PacketX cannot be used to block network traffic to build a firewall."

Answer 2

AFAIK you'll need low-level tools like C++ and WIN API to implement system-level layer of this firewall.