Filter libraries are special sets of NDIS interface library functions that route a received packet to a specific bound transport driver, based on packet target address. NDIS 3.0 currently supports the filter libraries listed below. A NIC driver can access filter library functions by including the appropriate header file.
Each filter library maintains a database for a network interface card. The database associates each NIC binding with a list of addresses. The filter library processes a packet and passes it on to each transport driver that has an address entry matching the destination address of the packet.