Patent ID: 8542679

Claim:
A method of limiting the frequency of floods within a data network, the floods arising as a data frame is routed to an unknown destination, the method comprising the steps of: (a) receiving on an ingress port a data frame intended for a destination station and containing a Medium Access Control (MAC) address of that station; (b) checking the destination MAC address with the contents of a MAC table; and thereby (c) determining whether the data frame is to be routed, discarded ( 60 , 66 ) or flooded ( 52 , 64 ) to all ports except the ingress port; and (d) respectively routing, discarding or flooding the data frame to all ports except the ingress port, as determined in Step (c), wherein the MAC table contains data in which a MAC address is mapped to a port number and to a flag value, the flag value being set to provide an indication to data frames that contain the MAC address as destination that the port number does not indicate an egress port to that destination.