Definition and Classification of MAC Address Entries
Definition of a MAC Address Table
A MAC address table records other devices' MAC addresses learned by the switch, interfaces on which MAC addresses are learned, and VLANs that the interfaces belong to. Before forwarding a packet, the switch looks up the destination MAC address of the packet the MAC address table. If a MAC address entry matches the destination MAC address, the switch forwards the packet from the corresponding outbound interface in the MAC address entry. If no MAC address entry matches the destination MAC address, the switch broadcasts the packet to all interfaces in the corresponding VLAN, except the inbound interface receiving the packet.
Classification of MAC Address Entries
MAC address entries are classified into dynamic, static, and blackhole entries. In addition, there are MAC address entries that are related to service types, for example, secure MAC, MUX MAC, authen MAC, and guest MAC. They are maintained by service modules and are converted from dynamic MAC address entries.
MAC Address Entry Type |
Characteristics |
Function |
|---|---|---|
Dynamic MAC address entry |
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Static MAC address entry |
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When static MAC address entries are configured, authorized users can use network resources and other users are prevented from using the bound MAC addresses to initiate attacks. |
Blackhole MAC address entry |
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Blackhole MAC address entries can filter out unauthorized users. |