Filter
Top Products
interface) before the system verifies that sufficient 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 show output. Remove the
configuration before re-applying a MAC learning limit with a lower value. Also, ensure that you can view
the Syslog messages on your session.
Setting the MAC Learning Limit
To set a MAC learning limit on an interface, use the following command.
• Specify the number of MAC addresses that the system can learn off a Layer 2 interface.
INTERFACE mode
mac learning-limit address_limit
Three options are available with the mac learning-limit command:
– dynamic
– no-station-move
– station-move
NOTE: An SNMP trap is available for mac learning-limit station-move. No other SNMP
traps are available for MAC Learning Limit, including limit violations.
mac learning-limit Dynamic
The MAC address table is stored on the Layer 2 forwarding information base (FIB) region of the CAM.
The Layer 2 FIB region allocates space for static MAC address entries and dynamic MAC address entries.
When you enable MAC learning limit, entries created on this port are static by default. When you
configure the dynamic option, learned MAC addresses are stored in the dynamic region and are subject
to aging. Entries created before this option is set are not affected.
Dell Networking OS Behavior: If you do not configure the dynamic option, the system does not detect
station moves in which a MAC address learned off of a MAC-limited port is learned on another port on
same line card. Therefore, any configured violation response to detected station moves is not performed.
When a MAC address is relearned on any other line card (any line card except the one to which the
original MAC-limited port belongs), the station-move is detected and the system takes the configured the
violation action.
mac learning-limit mac-address-sticky
Using sticky MAC addresses allows you to associate a specific port with MAC addresses from trusted
devices. If you enable sticky MAC, the specified port retains any dynamically-learned addresses and
prevents them from being transferred or learned on other ports. Up to 1000 sticky entries are supported
on a port.
If you configure mac-learning-limit and you enabled sticky MAC, all dynamically-learned addresses
are converted to sticky MAC addresses for the selected port. Any new MAC addresses learned on the port
are converted to sticky MAC addresses.
Layer 2
531