TechLibrary

Spanning-Tree
Spanning-Tree Protocols Supported BPDU Overview Loop Protection for Spanning-Tree Instance Interfaces Root Protection for Spanning-Tree Instance Interfaces BPDU Protection for Spanning-Tree Instance Interfaces VPLS Multihomed Layer 2 Ring and MPLS Infrastructure Overview VPLS Multihomed Layer 2 Ring and MPLS Infrastructure Topology Layer 2 Protocol Tunneling Through a Network Spanning-Tree Protocols in Logical Systems Bridge Priority for Election of Root Bridge and Designated Bridge Maximum Age for Awaiting Arrival of Hello BPDUs Hello Time for Root Bridge to Transmit Hello BPDUs Forward Delay Before Ports Transition to Forwarding State Spanning-Tree Instance Interface Spanning-Tree Instance Interface Priority Spanning-Tree Instance Interface Cost Spanning-Tree Instance Interface Point-to-Point Link Mode Spanning-Tree Instance Interface Configured as an Edge Port Spanning-Tree Protocol Trace Options MAC Address Rewriting Enabled for Layer 2 Protocol Tunneling Layer 2 Protocol Tunnel Interface Layer 2 Protocol to be Tunneled Loop Protection for a Spanning-Tree Instance Interface Root Protect for a Spanning-Tree Instance Interface BPDU Protection for Individual Spanning-Tree Instance Interfaces BPDU Protection on All Edge Ports of the Bridge VPLS Multihoming: Priority of the Backup Bridge VPLS Multihoming: Hold Time Before Switching to Primary Priority VPLS Multihoming: System Identifier for Bridges in the Ring VPLS Multihoming: Bridge Flush of MAC Cache

Spanning-Tree

Spanning-Tree Protocols Supported

BPDU Overview

Loop Protection for Spanning-Tree Instance Interfaces

Root Protection for Spanning-Tree Instance Interfaces

BPDU Protection for Spanning-Tree Instance Interfaces

VPLS Multihomed Layer 2 Ring and MPLS Infrastructure Overview

VPLS Multihomed Layer 2 Ring and MPLS Infrastructure Topology

Layer 2 Protocol Tunneling Through a Network

Spanning-Tree Protocols in Logical Systems

Bridge Priority for Election of Root Bridge and Designated Bridge

Maximum Age for Awaiting Arrival of Hello BPDUs

Hello Time for Root Bridge to Transmit Hello BPDUs

Forward Delay Before Ports Transition to Forwarding State

Spanning-Tree Instance Interface

Spanning-Tree Instance Interface Priority

Spanning-Tree Instance Interface Cost

Spanning-Tree Instance Interface Point-to-Point Link Mode

Spanning-Tree Instance Interface Configured as an Edge Port

Spanning-Tree Protocol Trace Options

MAC Address Rewriting Enabled for Layer 2 Protocol Tunneling

Layer 2 Protocol Tunnel Interface

Layer 2 Protocol to be Tunneled

Loop Protection for a Spanning-Tree Instance Interface

Root Protect for a Spanning-Tree Instance Interface

BPDU Protection for Individual Spanning-Tree Instance Interfaces

BPDU Protection on All Edge Ports of the Bridge

VPLS Multihoming: Priority of the Backup Bridge

VPLS Multihoming: Hold Time Before Switching to Primary Priority

VPLS Multihoming: System Identifier for Bridges in the Ring

VPLS Multihoming: Bridge Flush of MAC Cache

Configuration Examples
Blocking BPDUs on Aggregated Ethernet Enabling Loop Protection Configuring VPLS Root Topology Change Actions Example: Configuring VSTP on a Trunk Port with Tagged Traffic Example: Tracing Spanning-Tree Protocol Operations

Configuration Examples

Blocking BPDUs on Aggregated Ethernet

Enabling Loop Protection

Configuring VPLS Root Topology Change Actions

Example: Configuring VSTP on a Trunk Port with Tagged Traffic

Example: Tracing Spanning-Tree Protocol Operations

Configuration Tasks
Configuring MSTP Configuring MST Instances on a Physical Interface Disabling MSTP Provider Bridge Participation in RSTP or MSTP Instances RSTP or VSTP Forced to Run as IEEE 802.1D STP Configuring RSTP Reverting RSTP or VSTP Back From Forced IEEE 802.1D STP Provider Bridge Participation in RSTP or MSTP Instances System Identifier for Bridges in STP or RSTP Instances Configuring VSTP Topology Change Actions for Global Spanning Tree Behavior BPDU Protection for Individual Ports Configuring Loop Protection for a Spanning-Tree Instance Interface Enabling Root Protect for a Spanning-Tree Instance Interface Configuring BPDU Protection on Individual Interfaces Configuring BPDU Protection on All Edge Ports Configuring VPLS Root Protection Topology Change Actions to Control VLAN Spanning Tree Behavior Configuring Layer 2 Protocol Tunneling

Configuration Tasks

Configuring MSTP

Configuring MST Instances on a Physical Interface

Disabling MSTP

Provider Bridge Participation in RSTP or MSTP Instances

RSTP or VSTP Forced to Run as IEEE 802.1D STP

Configuring RSTP

Reverting RSTP or VSTP Back From Forced IEEE 802.1D STP

Provider Bridge Participation in RSTP or MSTP Instances

System Identifier for Bridges in STP or RSTP Instances

Configuring VSTP

Topology Change Actions for Global Spanning Tree Behavior

BPDU Protection for Individual Ports

Configuring Loop Protection for a Spanning-Tree Instance Interface

Enabling Root Protect for a Spanning-Tree Instance Interface

Configuring BPDU Protection on Individual Interfaces

Configuring BPDU Protection on All Edge Ports

Configuring VPLS Root Protection Topology Change Actions to Control VLAN Spanning Tree Behavior

Configuring Layer 2 Protocol Tunneling

Configuration Statements
[edit protocols mstp] Hierarchy Level [edit protocols rstp] Hierarchy Level [edit protocols vstp] Hierarchy Level protocols access-trunk bpdu-destination-mac-address (Spanning Tree) configuration-name cost disable edge extended-system-id force-version forward-delay hello-time interface (Spanning Tree) max-age max-hops mode msti mstp priority revision-level rstp traceoptions vlan (MSTP) vlan (VSTP) vstp [edit protocols layer2-control] Hierarchy Level interface (Layer 2 Protocol Tunneling) layer2-control mac-rewrite protocol no-root-port priority-hold-time system-id vpls-flush-on-topology-change [edit protocols layer2-control] Hierarchy Level bpdu-block disable-timeout interface (BPDU Blocking) interface (Layer 2 Protocol Tunneling)

Configuration Statements

[edit protocols mstp] Hierarchy Level

[edit protocols rstp] Hierarchy Level

[edit protocols vstp] Hierarchy Level

protocols

access-trunk

bpdu-destination-mac-address (Spanning Tree)

interface (Spanning Tree)

[edit protocols layer2-control] Hierarchy Level

interface (Layer 2 Protocol Tunneling)

vpls-flush-on-topology-change

[edit protocols layer2-control] Hierarchy Level

bpdu-block

disable-timeout

interface (BPDU Blocking)

interface (Layer 2 Protocol Tunneling)

Routine Monitoring
Checking the Status of Spanning-Tree Instance Interfaces Clearing the Blocked Status of a Spanning-Tree Instance Interface Checking for a MAC Rewrite Error Condition Blocking a Spanning-Tree Instance Interface Clearing a MAC Rewrite Error Condition Blocking a Spanning-Tree Instance Interface Tracing Spanning-Tree Operations

Routine Monitoring

Checking the Status of Spanning-Tree Instance Interfaces

Clearing the Blocked Status of a Spanning-Tree Instance Interface

Checking for a MAC Rewrite Error Condition Blocking a Spanning-Tree Instance Interface

Clearing a MAC Rewrite Error Condition Blocking a Spanning-Tree Instance Interface

Tracing Spanning-Tree Operations

Operational Commands
show bridge mac-table show mac-rewrite interface show spanning-tree bridge show spanning-tree interface show spanning-tree mstp configuration show spanning-tree statistics

Operational Commands

show bridge mac-table

show mac-rewrite interface

show spanning-tree bridge

show spanning-tree interface

show spanning-tree mstp configuration

show spanning-tree statistics