| 摘要 |
<p>A selection technique for filtering packets in a multi-port bridge (20) for a local area network, thus, preventing a source port for a packet from becoming a destination port for the packet. The bridge includes a memory (200) for storing packets and a plurality of ports(104-112). Each port includes a receive buffer (316) , a transmit buffer (318) and a memory pointer buffer (306). A packet is received by the receive buffer of a port. As the packet is still being received, a look-up table (204) is utilized to determine which one or ones of the plurality of ports are the appropriate destination ports for the packets. Each of the ports is assigned a respective one of the signal lines (102A) of the communication bus (102). A product of utilizing the look-up tables is referred to as a bit-map of the destination ports for the packet. The bit-map includes a logic level for each signal line assigned to a port wherein the logic level is indicative of whether the corresponding port is a destination port for the packet. The bit-map is placed on the communication bus which is monitored by each port. If the source port is designated as a destination port in the bit-map, this indicates that the source and destination nodes are on the same segment of the network (intra-segment communication). From the bit map, the source port also determines whether any other port is designated as a destination for the packet. If no other port is designated as a destination, the source port discards the incoming packet, thus filtering the packet. If, however, any other port is also designated as a destination for the packet, the source port continues receiving the packet for transmission by such other port.</p> |
