Firewall-Hook Drivers
The following functions are used by a firewall-hook driver to manage packets that are transferred to and from the TCP/IP protocol driver. Firewall-hook drivers are used by the TCP/IP protocol driver to determine how to process incoming and outgoing packets. However, it is not recommended to implement a firewall-hook driver for Microsoft Windows XP and later versions of the operating system. For more information, see Firewall-Hook Drivers.