A static entry does not age and does not get updated through the learning process.
A static entry is considered permanent because it is retained in the database if the switch is reset or a power off/on cycle occurs. A static entry is maintained exactly as it was created. Conditions that cause dynamic entries to be updated, such as VLAN or port configuration changes, do not affect static entries.
To create a permanent static FDB entry, see Adding a Permanent Unicast Static Entry.
If a duplicate MAC address is learned on a port other than the port where the static entry is defined, all traffic from that MAC address is dropped. By default, the switch does not report duplicate addresses. However, you can configure the switch to report these duplicate addresses as described in Managing Reports of Duplicate MAC Addresses for Static Entries.
A locked static entry is an entry that was originally learned dynamically, but has been made static (locked) using the MAC address lock-down feature. It is identified by the “s,” “p,” and “l” flags in show fdb command output and can be deleted using the delete fdb command. See MAC Address Lockdown for more information about this feature.
Note
Static FDB entries created on EAPS- or STP-enabled ports forward traffic irrespective of the port state. Consequently, you should avoid such a configuration.