Consolidated Platform Configuration Guide, Cisco Ios Release 15.2(4)E (Catalyst 2960-X Switches - Cisco Catalyst 2960 series Configuration Manual

Examples
This example shows how to prevent a port from automatically interoperating with a connecting device that
is running Rapid PVST+:
Switch(config)# interface1/0/1
Switch(config-if)# spanning-tree mst simulate pvst disable
The following sample output shows the system message you receive when a SSTP BPDU is received on a
port and PVST+ simulation is disabled:
Message
SPANTREE_PVST_PEER_BLOCK: PVST BPDU detected on port %s [port number].
Severity
Critical
Explanation
A PVST+ peer was detected on the specified interface on the switch. PVST+
simulation feature is disabled, as a result of which the interface was
moved to the spanning tree
Blocking state.
Action
Identify the PVST+ switch from the network which might be configured
incorrectly.
The following sample output shows the system message you receive when peer inconsistency on the interface
is cleared:
Message
SPANTREE_PVST_PEER_UNBLOCK: Unblocking port %s [port number].
Severity
Critical
Explanation
The interface specified in the error message has been restored to normal
spanning tree state.
Action
None.
This example shows the spanning tree status when port 1/0/1 has been configured to disable PVST+ simulation
and is currently in the peer type inconsistent state:
Switch# show spanning-tree
VLAN0010
Spanning tree enabled protocol mstp
Root ID Priority
Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Interface
---------------- ---- --- --------- -------- -------------------------
Gi1/0/1
This example shows the spanning tree summary when PVST+ simulation is enabled in the MSTP mode:
Switch# show spanning-tree summary

Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)

282
32778
Address 0002.172c.f400
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Address 0002.172c.f400
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Role Sts Cost
Desg BKN*4
Prio.Nbr Type
128.270 P2p *PVST_Peer_Inc