Dell S6000-ON, Configuration Manual

Page: 513 / 1080

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 4/24/1
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.
NOTE: The CAM-check failure message beginning in Dell Networking OS version 8.3.1.0 is different
from versions 8.2.1.1 and earlier, which read:
% Error: ACL returned error
% Error: Remove existing limit configuration if it was configured before
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 from a MAC-limited port is learned on another port on the
same system. 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.
Layer 2
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