Security filtering for TCP/IP allows you to control the type of network traffic passed up the TCP/IP protocol stack to upper-layer protocols and programs. Security filters are one of the security mechanisms typically used on Internet servers.
TCP/IP security filters control the ports on which TCP connections and UDP datagrams are accepted (For more information ,see Appendix B, "Port Reference for MS TCP/IP.") The filters also control which IP protocol can be assessed by using raw sockets.
If TCP/IP security filters are configured on a computer running under Windows NT, incoming connection requests and datagrams are accepted or rejected based on the configured security filters. Outgoing connection requests and datagrams are not affected.
Security filters are configured separately for each network adapter to which TCP/IP is bound. Filters are applied to network traffic based on the adapter that received the traffic.
For specific information about configuring advanced TCP/IP security, see Microsoft TCP/IP Help.