| 摘要 |
<p>An emulated local area network (ELAN) bridging technique employs unicast and multicast virtual connections (VCs) among ELAN bridges (72). 'Known' ELAN frames, i.e., frames whose MAC addresses have been learned, are exchanged among the bridges on the unicast VCs. The multicast VCs are used to multicast 'broadcast' and 'unknown' ELAN frames, where 'broadcast' frames contain a broadcast MAC address and 'unknown' frames contain MAC addresses that have not been learned. Each bridge maintains an association (80) between each unicast VC and the multicast VC for the same bridge. For frames received from another bridge on a multicast VC, an association (82) is established between the source MAC address and the unicast VC associated with the multicast VC on which the frame was received. The MAC-VC association is used for forwarding received frames to other bridges in the ELAN using the specified unicast VCs.</p> |
