Hi Siti Lestari
When Port Security is configured and an unmanaged hub introduces multiple MAC addresses on a port that is only allowed to learn a limited number. Once the violation occurs, the switch places the interface into an err-disable state to protect the network.
To enable automatic recovery, you can configure err-disable recovery globally on the switch. For example:
errdisable recovery cause psecure-violation
errdisable recovery interval 300
In this example, the switch will automatically attempt to bring the port back online after 300 seconds (5 minutes). You can verify the current recovery settings by running: show errdisable recovery
One thing I usually recommend is reviewing the Port Security configuration as well, especially if users may occasionally connect hubs, docking stations, or other devices that can introduce additional MAC addresses. If this answer helped point you in the right direction, please feel free to click "Accept Answer" so others with a similar issue can find the solution more easily.