I download netfilter sdk demo and fallow the install instructions. NetFilter2.sys copied to system32\driver folder and register with nfregdrv.exe netfilter2 command. I did these steps with install.bat with run as admin rights.
When i compile and run Delphi sample everythings fine. But CSharp example doesn't build.
"System.DllNotFoundException: Unable to load DLL 'nfapi': The
specified module could not be found. (Exception from HRESULT:
i ask to netfilter.com and Vitaly answer me. It's about debug mode. i select release and run succesfully. If you want to debug, you have to copy manually all required C++ dlls from the appropriate release_c_api folder.