Displays the reasons for placing a port in a non-forwarding state.
| stpd_name | Specifies an STPD name on the switch. | 
| port_list | Specifies one or more ports or slots and ports. | 
| non-forwarding-reasons | Displays only reasons for placing a port in a non-forwarding state. | 
N/A
The following example displays the non-forwarding reasons on port 1:10 in STP domain r1:
show stpd r1 ports 1:10 non-forwarding-reason
Port        Reason
----------------------------------------------------------------------------------------                                                   
1:1         Placed in listening state because it is in dispute.
1:2         Not been placed in a non-forwarding state due to any exceptional condition.
1:3         Placed in listening or blocking state by the Loop Protect feature.
1:4         Placed in listening state by the Loop Protect feature, but this condition
            may be normal because the link partner does not support Loop Protect.
1:5         Placed in blocking state because a loopback condition has been detected.
1:6         Unknown non-forwarding reason.        
      
    This command was first available in ExtremeXOS 15.7.1.
This command is available on all ExtremeSwitching Universal switches.