|Data type||Range||Default value|
|REG_DWORD||0 | 1||0|
Determines whether TCP/IP filters datagrams and TCP sync characters (SYNs).
If the value of this entry is 1, TCP/IP filters all incoming UDP datagrams, raw IP datagrams, and TCP SYNs. You can customize the filtering for each interface by using the UdpAllowedPorts, TcpAllowedPorts, and RawIpAllowedProtocols entries.
This entry does not affect packets that are not filtered by IP, such as packets routed through IP to other computers, and incoming packets that are filtered in the transports before being delivered to the local computer.
To change the value of this entry, use Network and Dial-up Connections. Right-click Local Area Connection, click Properties, click Internet Protocol (TCP/IP), and click the Properties button. In the bottom, right corner of the Internet Protocol (TCP/IP) Properties page, click the Advanced button, click the Options tab, click TCP/IP filtering, and then click Properties. This entry is associated with the Enable TCP/IP Filtering (All adapters) check box..