2166 CHAPTER 121: MAC ADDRESS TABLE MANAGEMENT CONFIGURATION■ Unicast mode: If an entry is available for the destination MAC address, thedevice forwards the frame directly from the hardware.■ Broadcast mode: If the device receives a frame with the destination addressbeing all Fs, or no entry is available for the destination MAC address, the devicebroadcasts the frame to all the interfaces except the receiving interface.Figure 636 Forward frames using the MAC address tableConfiguring MACAddress TableManagementThis section covers these topics:■ “Configuring MAC Address Entries” on page 2166■ “Disabling MAC Address Learning on an Ethernet Port or Aggregation PortGroup” on page 2167■ “Configuring MAC Address Aging Timer” on page 2167■ “Configuring Maximum Number of MAC Addresses an Ethernet Port orAggregation Port Group Can Learn” on page 2168Configuring MACAddress EntriesFollow these steps to add, modify, or remove entries in the MAC address table:Disabling Global MACAddress LearningYou may need to disable MAC address learning sometimes to prevent the MACaddress table from being saturated, for example, when your device is beingattacked by a great deal of packets with different source MAC addresses.Port 1 Port 2MAC address PortMAC A 1MAC B 1MAC C 2MAC D 2MAC AMAC BMAC CMAC DTo do... Use the command... RemarksEnter system view system-view -Add/modify a MAC addressentrymac-address blackhole mac-address vlanvlan-idRequiredmac-address { dynamic | static }mac-address interface interface-typeinterface-number vlan vlan-idEnter Ethernet interface view interface interface-type interface-number -Add/modify MAC addressentries under the specifiedinterface viewmac-address { dynamic | static }mac-address vlan vlan-idRequired
