Configuring Pvst Simulation Per Port - Cisco Nexus 9000 Series Configuration Manual

Configuring STP Extensions Using Cisco NX-OS
This example shows how to prevent the device from automatically interoperating with a connecting device
that is running Rapid PVST+:
switch# config t
switch(config)# no spanning-tree mst simulate pvst global
switch(config)# exit
switch#

Configuring PVST Simulation Per Port

PVST simulation is enabled by default. By default, all interfaces on the device interoperate between MST
Note
and Rapid PVST+.
You can configure PVST simulation only when you are running MST on the device (Rapid PVST+ is the
default STP mode). MST interoperates with Rapid PVST+. However, to prevent an accidental connection to
a device that does not run MST as the default STP mode, you may want to disable this automatic feature. If
you disable PVST simulation, the MST-enabled port moves to the blocking state once it detects that it is
connected to a Rapid PVST+-enabled port. This port remains in the inconsistent state until the port stops
receiving Rapid PVST+ BPDUs, and then the port resumes the normal STP transition process.
You can block this automatic feature either globally or per port.
Procedure
Step 1
Step 2
Step 3
Command or Action
config t
Example:
switch# config t
switch(config)#
interface {{type slot/port} |{port-channel
number}}
Example:
switch(config)# interface ethernet
3/1
switch(config-if)#
spanning-tree mst simulate pvst disable
or spanning-tree mst simulate pvst or no
spanning-tree mst simulate pvst
Example:
switch(config-if)# spanning-tree mst
simulate pvst
Cisco Nexus 9000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
Configuring PVST Simulation Per Port
Purpose
Enters configuration mode.
Specifies an interface to configure, and enters
interface configuration mode.
• spanning-tree mst simulate pvst disable
Disables specified interfaces from
automatically interoperating with a connected
device that is running in Rapid PVST+ mode.
By default, all interfaces on the device operate
between Rapid PVST+ and MST.
• spanning-tree mst simulate pvst
Reenables seamless operation between MST
and Rapid PVST+ on specified interfaces.
• no spanning-tree mst simulate pvst
175