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 |