Cannot change port security mode when a user is online

Symptom

Port security mode cannot be changed when an 802.1X authenticated or MAC authenticated user is online.

[DeviceGigabitEthernet1/0/1] undo port-security port-mode
 Error:Cannot configure port-security for there is 802.1X user(s) on line on port GigabitEthernet1/0/1.

Analysis

Changing port security mode is not allowed when an 802.1X authenticated or MAC authenticated user is online.

Solution

Use the cut command to forcibly disconnect the user from the port before changing the port security mode.

[Device-GigabitEthernet1/0/1] quit
[Device] cut connection interface gigabitethernet 1/0/1
[Device] interface gigabitethernet 1/0/1
[Device-GigabitEthernet1/0/1] undo port-security port-mode