A method and apparatus for managing the flow of data within a switching
device is provided. The switching device includes network interface cards
connected to a common backplane. Each interface card is configured to
support the maximum transfer rate of the backplane by maintaining a
"pending" queue to track data that has been received but for which the
appropriate routing destination has not yet been determined. The
switching device includes a switch controller that maintains a central
card/port-to-address table. When an interface card receives data with a
destination address that is not known to the interface card, the
interface card performs a direct memory access over a bus that is
separate from the backplane to read routing data directly from the
central table in the switch controller. Each interface card builds and
maintains a routing information table in its own local memory that only
includes a routing information for the destination addresses that the
interface card is most likely to receive.