Examples: Detecting Unidirectional Link Failure - Cisco Catalyst 2960 series Configuration Manual

Examples
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3 vlans
This example shows the interface details when PVST+ simulation is globally enabled, or the default
configuration:
Switch# show spanning-tree interface1/0/1 detail
Port 269 (GigabitEthernet
Port path cost 4, Port priority 128, Port Identifier 128.297.
Designated root has priority 32769, address 0013.5f20.01c0
Designated bridge has priority 32769, address 0013.5f20.01c0
Designated port id is 128.297, designated path cost 0
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
PVST Simulation is enabled by default
BPDU: sent 132, received 1
This example shows the interface details when PVST+ simulation is globally disabled:
Switch# show spanning-tree interface1/0/1 detail
Port 269 (GigabitEthernet
Port path cost 4, Port priority 128, Port Identifier 128.297.
Designated root has priority 32769, address 0013.5f20.01c0
Designated bridge has priority 32769, address 0013.5f20.01c0
Designated port id is 128.297, designated path cost 0
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
PVST Simulation is disabled by default
BPDU: sent 132, received 1
This example shows the interface details when PVST+ simulation is explicitly enabled on the port:
Switch# show spanning-tree interface1/0/1 detail
Port 269 (GigabitEthernet
Port path cost 4, Port priority 128, Port Identifier 128.297.
Designated root has priority 32769, address 0013.5f20.01c0
Designated bridge has priority 32769, address 0013.5f20.01c0
Designated port id is 128.297, designated path cost 0
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
PVST Simulation is enabled
BPDU: sent 132, received 1
This example shows the interface details when the PVST+ simulation feature is disabled and a PVST Peer
inconsistency has been detected on the port:
Switch# show spanning-tree interface1/0/1 detail
Port 269 (GigabitEthernet
Port path cost 4, Port priority 128, Port Identifier 128.297.
Designated root has priority 32769, address 0013.5f20.01c0
Designated bridge has priority 32769, address 0013.5f20.01c0
Designated port id is 128.297, designated path cost 0
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
PVST Simulation is disabled
BPDU: sent 132, received 1

Examples: Detecting Unidirectional Link Failure

This example shows the spanning tree status when port 1/0/1 detail has been configured to disable PVST+
simulation and the port is currently in the peer type inconsistent state:
Switch# show spanning-tree
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
284
6
1/0/1
) of VLAN0002 is forwarding
1/0/1
) of VLAN0002 is forwarding
1/0/1
) of VLAN0002 is forwarding
1/0/1
) of VLAN0002 is broken (PVST Peer Inconsistent)
0 0 0 6