Prevent multiple devices on single interface

[FatalXE]

Hi,
we have Cisco CBS250 series switches.
We deployed them recently with 802.1x
Unfortunately I found out that it is still possible to have multiple devices connected to single interface via unmanaged switch if authenticated computer is connected to the unmanag. switch.
How do I prevent this behaviour ? 
This is sample interface config : 

interface range GigabitEthernet 1-36
switchport mode access
switchport access vlan 1
dot1x port-control auto
dot1x guest-vlan enable

Thanks

[balaji.bandi]

If you do not want any other device connection behind the port, then use host most.

most cases people have Phone and PC connected to same port.  if you have only 1 PC then check :

dot1x host-mode

https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/CLI/cbs-250-cli/802_1X_Commands.html#wp3356823295

[marce1000]

 - Look into using port security as explained in :
               https://www.cisco.com/c/en/us/support/docs/smb/switches/Cisco-Business-Switching/kmgmt-2944-demonstration-port-security-default-changes.html

 M.