Description: The MIB module representing IP filter specifications in Zhone Technologies products. IP filtering is typically performed to enhance network security by limiting what access is allowed between two networks. Filtering is also effective in eliminating certain denial-of-service attacks. Packet filtering also provides a framework for sanity checking packet headers, and rejecting packets that are unlikely (or that should be impossible). In this way, packet filtering can prevent certain unfortunate mistakes from shutting a network down.