Maipu Administration Guide

Configure Limitations on MAC Address Learning

Limitations on MAC address learning is categorized into three types: limitations on port- based dynamic MAC address learning, and limitations on VLAN-based dynamic MAC address learning, and limitations on system-based dynamic MAC address learning

If a large number of dynamic MAC address entries have been learned by the device, it takes a long time for the device to search the MAC address table before forwarding packets, and this may cause degradation of the device performance. Therefore, you can configure limitations on dynamic MAC address learning to improve the device performance. If you configure limitations on dynamic MAC address learning on a port or VLAN, the number of access terminals can be controlled.

Configuration Condition

None

Configure Limitations on Port-Based Dynamic MAC Address Learning

If the number of MAC address entries that have been learned by a port has reached the threshold value, the port discards the packets whose source MAC addresses are not in the MAC address forwarding table.

Table 8-5 Configuring Limitations on Port-Based Dynamic MAC Address Learning

Step	Command	Description
Enter the global configuration mode.	configure terminal	-
Enter the L2 Ethernet interface configuration mode.	interface interface-name	Either After entering the L2 Ethernet interface configuration mode, the subsequent configuration takes effect only on the current port. After entering the aggregation group configuration mode, the subsequent configuration takes effect only on the aggregation group.
Enter the aggregation group configuration mode.	interface link-aggregation link-aggregation-id
Configure limitations on port-based dynamic MAC address learning.	mac-address max-mac- count max-mac-count-value	Mandatory. By default, there are no limitations on dynamic MAC address learning on a port. The range of the maximum number of the dynamic learned MAC addresses is from 1 to the maximum address entries the hardware chip can learn.

In configuring limitations on port-based dynamic MAC address learning, if the configured threshold value is smaller than the number of existing dynamic MAC address entries on the port, the device prompts to manually clear some existing dynamic MAC address entries. After the MAC addresses are cleared, the configuration takes effect immediately.

Configure Limitations on VLAN-Based Dynamic MAC Address Learning

If the number of MAC address entries that have been learned by a specified VLAN has reached the threshold value, the VLAN discards the packets whose source MAC addresses are not in the MAC address forwarding table.

Table 8-6 Configuring Limitations on VLAN-Based Dynamic MAC Address Learning

Step

Command

Description

Enter the global configuration mode.

configure terminal

Configure limitations on VLAN-based dynamic MAC address learning.

mac-address vlan vlan-id max-mac-count max-mac-count-value

Mandatory.

By default, there are no limitations on dynamic MAC address learning in a VLAN.

The range of the maximum number of the dynamic learned MAC addresses is from 1 to the maximum address entries the hardware chip can learn.

In configuring limitations on VLAN-based dynamic MAC address learning, if the configured threshold value is smaller than the number of existing dynamic MAC address entries in the current VLAN, the device prompts to manually clear some existing dynamic MAC address entries. After the MAC addresses are cleared, the configuration takes effect immediately.

Configure Limitations on System-Based Dynamic MAC Address Learning

If the number of MAC address entries that have been learned in the system has reached the threshold value, the system discards the packets whose source MAC addresses are not in the MAC address forwarding table.

Table 8-7 Configuring Limitations on System-Based Dynamic MAC Address Learning