27.14.2 Checking the status of common spanning tree functionality
Use the show spanning-tree detail command to check information about Spanning Tree Protocols. The figure below shows an example for VLAN 10 PVST+.
You can check that PortFast is set to PORT1/0/3, 1/0/4, or 1/0/5 by PortFast items. Port 1/0/3 has a PortFast, and port 1/0/4 has a BPDU guard in addition to PortFast. This indicates that operation is running normally, without any unintended BPDU reception from any port. Ports 1/0/5 are configured with BPDU filtering.
You can check that the loop guard is set to port 1/0/2 in Loop Guard items. Root Guard entry shows that Root Guard is set to port 1/0/6. The Link Type item for each port can be used to check the link type. All ports run as point-to-point.
> show spanning-tree vlan 10 detail Date 20XX/10/21 18:13:59 UTC VLAN 10 PVST+ Spanning Tree:Enabled Mode:Rapid PVST+ Bridge ID Priority:32778 MAC Address:0012.e210.3004 Bridge Status:Designated Path Cost Method:Short Max Age:20 Hello Time:2 Forward Delay:15 Root Bridge ID Priority:32778 MAC Address:0012.e210.1004 Root Cost:4 Root Port:1/0/1 Max Age:20 Hello Time:2 Forward Delay:15 Port Information Port:1/0/1 Up Status:Forwarding Role:Root Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:OFF PortFast:OFF BpduFilter:OFF Root Guard:OFF BPDU Parameters(20XX/10/21 18:13:59): Designated Root Priority:32778 MAC address:0012.e210.1004 Designated Bridge Priority:32778 MAC address:0012.e210.1004 Root Path Cost:0 Port ID Priority:128 Number:1 Message Age Time:0(3)/20 Port:1/0/2 Up Status:Discarding Role:Alternate Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:ON PortFast:OFF BpduFilter:OFF Root Guard:OFF BPDU Parameters(20XX/10/21 18:13:58): Designated Root Priority:32778 MAC address:0012.e210.1004 Designated Bridge Priority:32778 MAC address:0012.e210.2004 Root Path Cost:4 Port ID Priority:128 Number:1 Message Age Time:1(3)/20 Port:1/0/3 Up Status:Forwarding Role:Designated Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:OFF PortFast:ON (BPDU not received) BpduFilter:OFF Root Guard:OFF Port: 1/0/4 Up Status:Forwarding Role:Designated Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:OFF PortFast:BPDU Guard(BPDU not received) BpduFilter:OFF Root Guard:OFF Port: 1/0/5 Up Status:Forwarding Role:Designated Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:OFF PortFast:ON(BPDU not received) BpduFilter:ON Root Guard:OFF Port: 1/0/6 Up Status:Forwarding Role:Designated Priority:128 Cost:4 Link Type:point-to-point Compatible Mode:- Loop Guard:OFF PortFast:OFF BpduFilter:OFF Root Guard:ON |