Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 309

MAC Learning Limit This section describes the following: • MAC Learning Limit Dynamic • MAC Learning Limit Station-Move • Learning Limit Violation Actions • Station Move Violation Actions • Recovering from Learning Limit and Station Move Violations The MAC address learning limit is a method of port security on Layer 2 port-channel and physical interfaces, and virtual local area networks (VLANs). It allows you to set an upper limit on the number of MAC addresses that are learned on an interface/VLAN. After the limit is reached, the system drops all traffic from a device with an unlearned MAC address. FTOS Behavior: When configuring the MAC learning limit on a port, the configuration is accepted (becomes part of the running-config and show mac learning-limit interface) before the system verifies that sufficient content addressable memory (CAM) space exists. If the CAM check fails, a message is displayed: %E90MH:5 %ACL_AGENT-2-ACL_AGENT_LIST_ERROR: Unable to apply access-list Mac-Limit on TenGigabitEthernet 5/84 In this case, the configuration is still present in the running-config and the show output. Remove the configuration before re-applying a MAC learning limit with a lower value. Also, ensure that you can view the syslog message on your session. To set a MAC learning limit on an interface, use the following command: Task Specify the number of MAC addresses that the system can learn off a Layer 2 interface. Command Syntax mac learning-limit address_limit Command Mode INTERFACE Three options are available with the mac learning-limit command: dynamic, no-station-move, and station-move. Note: A simple network management protocol (SNMP) trap is available for mac learning-limit station-move. No other SNMP traps are available for the MAC learning limit, including limit violations. Layer 2 | 307