Understanding the Lockdown Timer

The lockdown timer works in the following ways:

• When you enable this feature on a port, existing MAC entries for the port begin aging out based on the configured MAC lockdown timer value.
• If you move a device from one port to another, its MAC address entry is updated with the new port information, including the lockdown timer value configured for that port.
• If this feature is enabled on a port and you decrease the lockdown timer value for that port, all of the MAC FDB entries for that port will time out and be removed at the next polling interval.
• When you disable the lockdown timer on a port, existing MAC address entries for the port will time out based on the FDB aging period.
• The MAC lockdown timer takes effect when the port goes down/restarted.