Operation Manual – MAC Address TableH3C S7500 Series Ethernet Switches Chapter 1 MAC Address Table Management1-5z If the aging time is too short, the switch may remove valid MAC address entries.This decreases the forwarding performance of the switch.Follow these steps to set aging time for MAC address entries:To do… Use the command… RemarksEnter system view system-view —Set the aging time of MACaddress entriesmac-address timer{ aging age | no-aging }RequiredThe default aging time is300 seconds.This command is used in system view and applies to all ports. Aging applies to onlydynamic MAC addresses that are learnt or configured to age out.Normally, you are recommended to use the default aging time, namely, 300 seconds.The no-aging keyword specifies that MAC address entries do not age out.1.2.4 Setting the Maximum Number of MAC Addresses a Port can LearnThe MAC address learning mechanism enables an Ethernet switch to acquire the MACaddresses of the network devices on the segment connected to the ports of the switch.The switch directly forwards the packets destined for these MAC addresses. Anoversized MAC address table may decrease the forwarding performance of the switch.By setting the maximum number of MAC addresses that can be learnt from individualports, you can control the number of the MAC address entries the MAC address tablecan dynamically maintains. If you have set the maximum number of MAC addressesthat a port can learn to count, the port stops learning MAC addresses when the numberof MAC addresses learned by the port reaches count.Follow these steps to set the maximum number of MAC addresses a port can learn:To do… Use the command… RemarksEnter system view system-view —Enter Ethernet port view interface interface-typeinterface-number —Set the maximum numberof MAC addresses theport can learnmac-addressmax-mac-count countRequiredBy default, the number ofthe MAC addresses a portcan learn is not limited.1.2.5 Disabling MAC Address LearningTo gain better control over network security, you can use the following commands todisable the current port from learning MAC addresses.
