Reference Guide

Layer 2 | 643
Command
History
Usage
Information
This command and its options are supported on physical interfaces, static LAGs, LACP LAGs, and
VLANs.
If the vlan option is not specified, then the MAC address counters is not VLAN-based. That is, the
sum of the addresses learned on all VLANs (not having any learning limit configuration) is counted
against the MAC learning limit.
MAC Learning Limit violation logs and actions are not available on a per-VLAN basis.
With the keyword no-station-move option, MAC addresses learned through this feature on the selected
interface will persist on a per-VLAN basis, even if received on another interface. Enabling or disabling
this option has no effect on already learned MAC addresses.
Once the MAC address learning limit is reached, the MAC addresses do not age out unless you add the
dynamic option. To clear statistics on MAC address learning, use the clear counters command with
the learning-limit parameter.
When a channel member is added to a port-channel and there is not enough ACL CAM space, then the
MAC limit functionality on that port-channel is undefined. When this occurs, un-configure the existing
configuration first and then reapply the limit with a lower value.
Related
Commands
mac learning-limit learn-limit-violation
c e s
Configure an action for a MAC address learning-limit violation.
Syntax
mac learning-limit learn-limit-violation {log | shutdown}
To return to the default, use the no mac learning-limit learn-limit-violation {log | shutdown}
command.
Parameters
Version 8.3.5.0 Introduced on the S55.
Version 8.3.1.0
Added
vlan option on E-Series.
Version 8.2.1.0 Introduced on S-Series
Version 7.7.1.0
Introduced on C-Series; added
station-move option
Version 6.5.1.0 Added support for MAC Learning-Limit on LAG
Note: If you configure this command on an interface in a routed VLAN, and once the MAC
addresses learned reaches the limit set in the mac learning-limit command, IP protocols are
affected. For example, VRRP sets multiple VRRP Masters, and OSPF may not come up.
clear counters
Clear counters used in the
show interface command
clear mac-address-table
dynamic
Clear the MAC address table of all MAC address learned dynamically.
show mac learning-limit Display MAC learning-limit configuration.
log Enter the keyword log to generate a syslog message on a learning-limit
violation.
shutdown
Enter the keyword shutdown to shut down the port on a learning-limit
violation.