Filter libraries are special sets of NDIS interface library wrapper functions that route a packet from the NIC driver to specific bound transport drivers. Each filter library maintains a transport database for the associated network, Ethernet, Token Ring, or FDDI. The database associates each network interface card binding with a list of transport driver addresses. The NIC driver must indicate each packet received through the filter library appropriate to the network. Then the filter library processes the received packet and passes it on to each transport driver that has an address entry matching the packet destination address. For more information about NIC driver action functions, see Section A.2.1.