1-11 MAC Address Table Managementz The term switch used throughout this chapter refers to a switching device in a generic sense or theswitching engine of a unified switch in the WX3000 series.z The sample output information in this manual was created on the WX3024. The output informationon your device may vary.z This chapter describes the management of static, dynamic, and blackhole MAC address entries.For information about the management of multicast MAC address entries, refer to the part relatedto multicast protocol.OverviewIntroduction to MAC Address TableA switch is mainly used to forward packets at the data link layer, that is, transmit the packets to thecorresponding ports according to the destination MAC address of the packets. To forward packetsquickly, a switch maintains a MAC address table, which is a Layer 2 address table recording the MACaddress-to-forwarding port association. Each entry in a MAC address table contains the following fields:z Destination MAC addressz ID of the VLAN which a port belongs toz Forwarding egress port numbers on the local switchWhen forwarding a packet, a switch adopts one of the two forwarding methods based on the MACaddress table entries.z Unicast forwarding: If the destination MAC address carried in the packet is included in a MACaddress table entry, the device forwards the packet through the forwarding egress port in the entry.z Broadcast forwarding: If the destination MAC address carried in the packet is not included in theMAC address table, the device broadcasts the packet to all ports except the one receiving thepacket.Introduction to MAC Address LearningMAC address table entries can be updated and maintained through the following two ways:z Manual configurationz MAC address learningGenerally, the majority of MAC address entries are created and maintained through MAC addresslearning. The following describes the MAC address learning process of the device:
