user manual
Table Of Contents
- Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
- Contents
- Preface
- New and Changed Information for this Release
- Overview
- Configuring Ethernet Interfaces
- Information About Ethernet Interfaces
- Configuring Ethernet Interfaces
- Configuring the UDLD Mode
- Changing an Interface Port Mode
- Configuring Interface Speed
- Disabling Link Negotiation
- Configuring the CDP Characteristics
- Enabling or Disabling CDP
- Enabling the Error-Disabled Detection
- Enabling the Error-Disabled Recovery
- Configuring the Error-Disabled Recovery Interval
- Configuring the Debounce Timer
- Configuring the Description Parameter
- Disabling and Restarting Ethernet Interfaces
- Displaying Interface Information
- Displaying Input Packet Discard Information
- Default Physical Ethernet Settings
- Configuring VLANs
- Configuring Private VLANs
- Information About Private VLANs
- Guidelines and Limitations for Private VLANs
- Configuring a Private VLAN
- Enabling Private VLANs
- Configuring a VLAN as a Private VLAN
- Associating Secondary VLANs with a Primary Private VLAN
- Configuring an Interface as a Private VLAN Host Port
- Configuring an Interface as a Private VLAN Promiscuous Port
- Configuring a Promiscuous Trunk Port
- Configuring an Isolated Trunk Port
- Configuring the Allowed VLANs for PVLAN Trunking Ports
- Configuring Native 802.1Q VLANs on Private VLANs
- Verifying the Private VLAN Configuration
- Configuring Access and Trunk Interfaces
- Configuring Switching Modes
- Configuring Rapid PVST+
- Information About Rapid PVST+
- Understanding STP
- Understanding Rapid PVST+
- Rapid PVST+ and IEEE 802.1Q Trunks
- Rapid PVST+ Interoperation with Legacy 802.1D STP
- Rapid PVST+ Interoperation with 802.1s MST
- Configuring Rapid PVST+
- Enabling Rapid PVST+
- Enabling Rapid PVST+ per VLAN
- Configuring the Root Bridge ID
- Configuring a Secondary Root Bridge
- Configuring the Rapid PVST+ Port Priority
- Configuring the Rapid PVST+ Pathcost Method and Port Cost
- Configuring the Rapid PVST+ Bridge Priority of a VLAN
- Configuring the Rapid PVST+ Hello Time for a VLAN
- Configuring the Rapid PVST+ Forward Delay Time for a VLAN
- Configuring the Rapid PVST+ Maximum Age Time for a VLAN
- Specifying the Link Type
- Restarting the Protocol
- Verifying Rapid PVST+ Configurations
- Information About Rapid PVST+
- Configuring Multiple Spanning Tree
- Information About MST
- Configuring MST
- MST Configuration Guidelines
- Enabling MST
- Entering MST Configuration Mode
- Specifying the MST Name
- Specifying the MST Configuration Revision Number
- Specifying the Configuration on an MST Region
- Mapping and Unmapping VLANs to MST Instances
- Mapping Secondary VLANs to Same MSTI as Primary VLANs for Private VLANs
- Configuring the Root Bridge
- Configuring a Secondary Root Bridge
- Configuring the Port Priority
- Configuring the Port Cost
- Configuring the Switch Priority
- Configuring the Hello Time
- Configuring the Forwarding-Delay Time
- Configuring the Maximum-Aging Time
- Configuring the Maximum-Hop Count
- Configuring PVST Simulation Globally
- Configuring PVST Simulation Per Port
- Specifying the Link Type
- Restarting the Protocol
- Verifying MST Configurations
- Configuring STP Extensions
- About STP Extensions
- Information About STP Extensions
- Configuring STP Extensions
- STP Extensions Configuration Guidelines
- Configuring Spanning Tree Port Types Globally
- Configuring Spanning Tree Edge Ports on Specified Interfaces
- Configuring Spanning Tree Network Ports on Specified Interfaces
- Enabling BPDU Guard Globally
- Enabling BPDU Guard on Specified Interfaces
- Enabling BPDU Filtering Globally
- Enabling BPDU Filtering on Specified Interfaces
- Enabling Loop Guard Globally
- Enabling Loop Guard or Root Guard on Specified Interfaces
- Verifying STP Extension Configuration
- About STP Extensions
- Configuring LLDP
- Configuring the MAC Address Table
- Configuring IGMP Snooping
- Configuring Traffic Storm Control
- INDEX

Procedure
PurposeCommand or Action
Enters configuration mode.switch# configure terminal
Step 1
Disables all interfaces on the switch from automatically
interoperating with connected switch that is running in Rapid
switch(config)# no spanning-tree
mst simulate pvst global
Step 2
PVST+ mode. The default for this is enabled; that is, by
default, all interfaces on the switch operate seamlessly
between Rapid PVST+ and MST.
This example shows how to prevent the switch from automatically interoperating with a connecting switch
that is running Rapid PVST+:
switch# configure terminal
switch(config)# no spanning-tree mst simulate pvst global
Configuring PVST Simulation Per Port
MST interoperates seamlessly with Rapid PVST+. However, to prevent an accidental connection to a switch
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 it is connected to a Rapid
PVST+-enabled port. This port remains in the inconsistent state until the port stops receiving BPDUs, and
then the port resumes the normal STP transition process.
You can block this automatic feature either globally or per port.
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configure terminal
Step 1
Specifies an interface to configure, and enters interface
configuration mode.
switch(config)# interface {{type
slot/port} | {port-channel number}}
Step 2
Disables specified interfaces from automatically
interoperating with connected switch that is running in
Rapid PVST+ mode.
switch(config-if)# spanning-tree mst
simulate pvst disable
Step 3
By default, all interfaces on the switch operate
seamlessly between Rapid PVST+ and MST.
Re-enables seamless operation between MST and Rapid
PVST+ on specified interfaces.
switch(config-if)# spanning-tree mst
simulate pvst
Step 4
Sets the interface to the switch-wide MST and Rapid
PVST+ interoperation that you configured using the
spanning-tree mst simulate pvst global command.
switch(config-if)# no spanning-tree
mst simulate pvst
Step 5
Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
110 OL-26590-01
Configuring Multiple Spanning Tree
Configuring PVST Simulation Per Port