Configuring RSTP Protocol
Understanding RSTP
Juniper Networks products use Rapid Spanning Tree Protocol (RSTP) on the network side of devices by default to provide quicker convergence time than the base Spanning Tree Protocol (STP) does. RSTP identifies certain links as point to point. When a point-to-point link fails, the alternate link can transition to the forwarding state, which speeds up convergence.
Benefits of Using RSTP
Some benefits of using the original STP are:
RSTP is faster than STP.
Voice and video work better with RSTP than they do with STP.
RSTP supports more ports than MSTP or VSTP.
RSTP is backward compatible with STP; therefore, switches do not all have to run RSTP.
On MX and ACX routers, you can configure RSTP, MSTP, and VSTP instance interfaces as edge ports. See Configuring a Spanning-Tree Instance Interface as an Edge Port for Faster Convergence.
Why is RSTP the Default Spanning-Tree Protocol?
RSTP evolved from the original STP IEEE 802.1D protocol to provide faster spanning-tree reconvergence after a switch port, switch, or LAN failure. Where STP took up to 50 seconds to respond to topology changes, RSTP responds to changes within the timeframe of three hello BPDUs (bridge protocol data units), or 6 seconds. This is the primary reason that RSTP is the default spanning-tree configuration.
EX Series switches configured to use STP actually run RSTP force version 0, which is compatible with STP.
Configuring Rapid Spanning Tree Protocol
You can configure Rapid Spanning Tree Protocol (RSTP) under the following hierarchy levels:
[edit logical-systems logical-system-name protocols]
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols]
[edit protocols]
[edit routing-instances routing-instance-name protocols]
The routing instance type can be either virtual-switch or layer2-control.
To configure the Rapid Spanning Tree Protocol:
- Enable RSTP as the version of spanning-tree protocol to
be configured:
[edit]
user@host@ edit ... protocols (STP Type) rstp (Optional) For compatibility with older bridges that do not support RSTP, you can force RSTP to run as the original IEEE 802.1D Spanning Tree Protocol (STP) version:
[edit ... protocols rstp]user@host# set force-version stpNote If RSTP has been forced to run as the original STP version, you can revert back to RSTP by first removing the force-version statement from the configuration and then entering the clear spanning-tree protocol-migration configuration mode command.
- (Optional) Enable provider bridge participation in the
RSTP instance:
[edit ... protocols rstp]
user@host# set bpdu-destination-mac-address provider-bridge-group - (Optional) Specify the extended system identifier used
in identifiers bridges that participate in RSTP:
[edit ... protocols rstp]
user@host# set extended-system-id identifier Configure the interfaces that participate in the RSTP instance.
- Enable configuration of the interface:
[edit ... protocols rstp]
user@host# edit interface interface-name - Configure the interface priority:
[edit ... protocols rstp interface interface-name]
user@host# set priority interface-priority - (Optional) By default, the interface link cost is determined
by the link speed. You can configure the interface link cost to control
which bridge is the designated bridge and which port is the designated
port:
[edit ... protocols rstp interface interface-name]
user@host# set cost interface-link-cost - Configure the interface link mode to identify point-to-point
links:
[edit ... protocols rstp interface interface-name]
user@host# set mode (p2p | shared)Specify p2p if the link is point to point. Specify shared if the link is a shared media.
- (Optional) Configure the interface as an edge port:
[edit ... protocols rstp interface interface-name]
user@host# set edgeEdge ports do not expect to receive bridge protocol data unit (BPDU) packets. If a BPDU packet is received for an edge port, the port becomes a non-edge port
- Enable configuration of the interface:
- Configure the bridge priority:
[edit ... protocols rstp]
user@host# set bridge-priority bridge-priorityFor more information, see Understanding Bridge Priority for Election of Root Bridge and Designated Bridge.
Configure hello BPDU timers.
- Configure the maximum expected arrival time of hello BPDUs:
[edit ... protocols rstp]
user@host# set max-age seconds - Configure the time interval at which the root bridge transmits
configuration BPDUs:
[edit ... protocols rstp]
user@host# set hello-time seconds
- Configure the maximum expected arrival time of hello BPDUs:
- (Optional) By default, the bridge port remains in the
listening and learning states for 15 seconds before transitioning
to the forwarding state. You can specify a delay from 4 through 20 seconds instead:
[edit ... protocols rstp]
user@host# set forward-delay seconds Verify the RSTP configuration:
[edit]... { # Optional logical system and/or routing instancerstp {force-version stp; # Optional.bpdu-destination-mac-address provider-bridge-group; # Optionalextended-system-id identifier; # Optional.interface interface-name {priority interface-priority;cost interface-link-cost; # Optional.mode (p2p | shared);edge; # Optional.}bridge-priority bridge-priority;max-age seconds;hello-time seconds;forward-delay seconds; # Optional.}}}
Configuring RSTP on EX Series Switches (CLI Procedure)
The default spanning-tree protocol for EX Series switches is Rapid Spanning Tree Protocol (RSTP). RSTP provides faster convergence times than the original Spanning Tree Protocol (STP). Because RSTP is configured by default, you only need to use this procedure If another spanning-tree protocol has been configured. In that case, you can reconfigure RSTP.
To enable RSTP:
- Disable the other configured spanning-tree protocol (MSTP):
To disable MSTP:
[edit protocols]
user@switch# set mstp disable
- Configure RSTP
To enable RSTP on a specific interface:
[edit protocols]
user@switch# set rstp interface interface-nameTo disable RSTP on a specific interface:
[edit protocols]
user@switch# set rstp interface interface-name disableTo enable RSTP on a range of interfaces:
[edit protocols]
user@switch# set rstp interface interface-range-nameTo enable RSTP on all interfaces:
[edit protocols]
user@switch# set rstp interface all
Example: Configuring Faster Convergence and Network Stability on ELS Switches with RSTP
This example uses Junos OS for EX Series switches with support for the Enhanced Layer 2 Software (ELS) configuration style. If your switch runs software that does not support ELS, see Example: Faster Convergence and Improved Network Stability with RSTP on EX Series Switches. For ELS details, see Using the Enhanced Layer 2 Software CLI.
EX Series switches use Rapid Spanning Tree Protocol (RSTP) by default to provide a loop-free topology.
When switches that support redundant Routing Engines use RSTP, it is important to keep RSTP synchronized on both Routing Engines so that no loss of service occurs after a Routing Engine switchover. Nonstop bridging protocol keeps Routing Engines synchronized.
This example describes how to configure RSTP and NSB on four EX Series switches:
Requirements
This example uses the following software and hardware components:
Junos OS Release 15.1 or later or later for EX Series switches
Four EX Series switches
Before you configure the switches for RSTP, be sure you have:
Installed and connected the four switches. See the hardware documentation for your switch.
Performed the initial software configuration on all switches. See Connecting and Configuring an EX Series Switch (CLI Procedure).
Overview and Topology
RSTP works by identifying certain links as point to point links and blocking other possible paths. When one of the point-to-point links fails, a designated alternate link transitions to the forwarding state and take over. Configuring nonstop bridging (NSB) on a switch with redundant Routing Engines keeps RSTP synchronized on both Routing Engines. This way, RSTP remains active immediately after a switchover because it is already synchronized to the backup Routing Engine. RSTP does not have to reconverge after a Routing Engine switchover when NSB is enabled because the neighbor devices do not detect an RSTP change on the switch. In this example, four EX Series switches are connected in the topology displayed in Figure 1 to create a loop-free topology with NSB applied to switches with dual Routing Engines.
Table 1 shows the components of the topology for this example.
You can configure RSTP only on physical interfaces, not on logical interfaces.
Table 1: Components of the Topology for Configuring RSTP
Property | Settings |
|---|---|
Switch 1 | The following interfaces on Switch 1 are connected in this way:
|
Switch 2 | The following interfaces on Switch 2 are connected in this way:
|
Switch 3 | The following interfaces on Switch 3 are connected in this way:
|
Switch 4 | The following interfaces on Switch 4 are connected in this way:
|
VLAN names and tag IDs | voice-vlan, tag 10 |
This configuration example creates a loop-free topology between four EX Series switches using RSTP.
An RSTP topology contains ports that have specific roles:
The root port is responsible for forwarding data to the root bridge.
The alternate port is a standby port for the root port. When a root port goes down, the alternate port becomes the active root port.
The designated port forwards data to the downstream network segment or device.
The backup port is a backup port for the designated port. When a designated port goes down, the backup port becomes the active designated port and starts forwarding data.
You also can create a loop-free topology between the aggregation layer and the distribution layer using redundant trunk links. For more information about configuring redundant trunk links, see Example: Configuring Redundant Trunk Links for Faster Recovery on Devices with ELS Support.
Configuring RSTP and Nonstop Bridging on Switch 1
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 1, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/13
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/9
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/11
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/13
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/9
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/11
unit 0 family ethernet-switching interface-mode trunk set protocols rstp
bridge-priority 16k set protocols rstp
interface all cost 1000 set protocols rstp
interface all mode point-to-point
If Switch 1 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 1, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset protocols layer2-control nonstop-bridgingNFX150 devices support only a single Routing Engine.
Step-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 1:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch1# set voice-vlan description “Voice VLAN”
user@switch1# set voice-vlan vlan-id 10
user@switch1# set employee-vlan description “Employee VLAN”
user@switch1# set employee-vlan vlan-id 20
user@switch1# set guest-vlan description “Guest VLAN”
user@switch1# set guest-vlan vlan-id 30
user@switch1# set camera-vlan description “Camera VLAN”
user@switch1# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch1# set ge-0/0/13 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch1# set ge-0/0/9 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch1# set ge-0/0/11 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch1# set ge-0/0/13 unit 0 family ethernet-switching interface-mode trunk
user@switch1# set ge-0/0/9 unit 0 family ethernet-switching interface-mode trunk
user@switch1# set ge-0/0/11 unit 0 family ethernet-switching interface-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch1# rstp bridge-priority 16k
user@switch1# rstp interface all cost 1000
user@switch1# rstp interface all mode point-to-point
Step-by-Step Procedure
If Switch 1 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 1:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch1# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch1# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit protocols layer2-control]
user@switch1# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 2
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 2, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/14
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/18
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/14
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/18
unit 0 family ethernet-switching interface-mode trunk set protocols rstp
bridge-priority 32k set protocols rstp
interface ge-0/0/14 cost 1000 set protocols rstp
interface ge-0/0/14 mode point-to-point
set protocols rstp
interface ge-0/0/18 cost 1000 set protocols rstp
interface ge-0/0/18 mode point-to-point
Starting with Junos OS Release 15.1 for EX Series and QFX Series switches with support for the Enhanced Layer 2 Software (ELS) configuration style, you can configure spanning tree parameters globally on all spanning tree interfaces. See Configuring RSTP on EX Series Switches (CLI Procedure) for additional information.
If Switch 2 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 2, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset protocols layer2-control nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 2:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch2# set voice-vlan description “Voice VLAN”
user@switch2# set voice-vlan vlan-id 10
user@switch2# set employee-vlan description “Employee VLAN”
user@switch2# set employee-vlan vlan-id 20
user@switch2# set guest-vlan description “Guest VLAN”
user@switch2# set guest-vlan vlan-id 30
user@switch2# set camera-vlan vlan-description “Camera VLAN”
user@switch2# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch2# set ge-0/0/14 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch2# set ge-0/0/18 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch2# set ge-0/0/14 unit 0 family ethernet-switching interface-mode trunk
user@switch2# set ge-0/0/18 unit 0 family ethernet-switching interface-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch2# rstp bridge-priority 32k
user@switch2# rstp interface ge-0/0/14 cost 1000
user@switch2# rstp interface ge-0/0/14 mode point-to-point
user@switch2# rstp interface ge-0/0/18 cost 1000
user@switch2# rstp interface ge-0/0/18 mode point-to-point
Step-by-Step Procedure
If Switch 2 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 2:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch2# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch2# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit protocols layer2-control]
user@switch2# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 3
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 3, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/26
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/28
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/24
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/26
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/28
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/24
unit 0 family ethernet-switching interface-mode trunk set protocols rstp
bridge-priority 8k set protocols rstp
interface ge-0/0/26 cost 1000 set protocols rstp
interface ge-0/0/26 mode point-to-point
set protocols rstp
interface ge-0/0/28 cost 1000 set protocols rstp
interface ge-0/0/28 mode point-to-point
set protocols rstp
interface ge-0/0/24 cost 1000 set protocols rstp
interface ge-0/0/24 mode point-to-point
If Switch 3 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 3, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset protocols layer2-control nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 3:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch3# set voice-vlan description “Voice VLAN”
user@switch3# set voice-vlan vlan-id 10
user@switch3# set employee-vlan description “Employee VLAN”
user@switch3# set employee-vlan vlan-id 20
user@switch3# set guest-vlan description “Guest VLAN”
user@switch3# set guest-vlan vlan-id 30
user@switch3# set camera-vlan description “Camera VLAN”
user@switch3# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch3# set ge-0/0/26 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch3# set ge-0/0/28 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch3# set ge-0/0/24 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch3# set ge-0/0/26 unit 0 family ethernet-switching interface-mode trunk
user@switch3# set ge-0/0/28 unit 0 family ethernet-switching interface-mode trunk
user@switch3# set ge-0/0/24 unit 0 family ethernet-switching interface-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch3# rstp bridge-priority 8k
user@switch3# rstp interface ge-0/0/26 cost 1000
user@switch3# rstp interface ge-0/0/26 mode point-to-point
user@switch3# rstp interface ge-0/0/28 cost 1000
user@switch3# rstp interface ge-0/0/28 mode point-to-point
user@switch3# rstp interface ge-0/0/24 cost 1000
user@switch3# rstp interface ge-0/0/24 mode point-to-point
Step-by-Step Procedure
If Switch 3 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 3:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch3# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch3# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit protocols layer2-control]
user@switch3# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 4
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 4, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/23
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/19
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/23
unit 0 family ethernet-switching interface-mode trunk set interfaces ge-0/0/19
unit 0 family ethernet-switching interface-mode trunk set protocols rstp
bridge-priority 16k set protocols rstp
interface ge-0/0/23 cost 1000 set protocols rstp
interface ge-0/0/23 mode point-to-point
set protocols rstp
interface ge-0/0/19 cost 1000 set protocols rstp
interface ge-0/0/19 mode point-to-point
If Switch 4 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 4, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset protocols layer2-control nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 4:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch4# set voice-vlan description “Voice VLAN”
user@switch4# set voice-vlan vlan-id 10
user@switch4# set employee-vlan description “Employee VLAN”
user@switch4# set employee-vlan vlan-id 20
user@switch4# set guest-vlan description “Guest VLAN”
user@switch4# set guest-vlan vlan-id 30
user@switch4# set camera-vlan description “Camera VLAN”
user@switch4# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch4# set ge-0/0/23 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch4# set ge-0/0/19 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch4# set ge-0/0/23 unit 0 family ethernet-switching interface-mode trunk
user@switch4# set ge-0/0/19 unit 0 family ethernet-switching interface-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch4# rstp bridge-priority 16k
user@switch4# rstp interface ge-0/0/23 cost 1000
user@switch4# rstp interface ge-0/0/23 mode point-to-point
user@switch4# rstp interface ge-0/0/19 cost 1000
user@switch4# rstp interface ge-0/0/19 mode point-to-point
Step-by-Step Procedure
If Switch 4 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 4:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch4# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch4# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit protocols layer2-control]
user@switch4# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Verification
To confirm that the configuration is working properly, perform these tasks on both Routing Engines:
Verifying RSTP Configuration on Switch 1
Purpose
Verify the RSTP configuration on Switch 1.
Action
Use the operational mode command:
user@switch1> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/13 128:526 128:526 16384.0019e25040e0 1000 BLK ALT
ge-0/0/9 128:522 128:522 32768.0019e2503d20 1000 BLK ALT
ge-0/0/11 128:524 128:524 8192.0019e25051e0 1000 FWD ROOT
Meaning
The operational mode command show spanning-tree interface shows that ge-0/0/13 is in a forwarding state. The other interfaces on Switch 1 are blocking.
Verifying RSTP Configuration on Switch 2
Purpose
Use this procedure to verify the RSTP configuration on both Switch 2 Routing Engines.
Action
Use the operational mode command:
user@switch2> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/14 128:527 128:527 32768.0019e2503d20 1000 FWD DESG
ge-0/0/18 128:529 128:529 8192.0019e25051e0 1000 FWD ROOT
Meaning
The operational mode command show spanning-tree interface shows that ge-0/0/18 is in a forwarding state and is the root port.
Verifying RSTP Configuration on Switch 3
Purpose
Use this procedure to verify the RSTP configuration on both Switch 3 Routing Engines.
Action
Use the operational mode commands:
user@switch3> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/26 128:539 128:539 8192.0019e25051e0 1000 FWD DESG
ge-0/0/28 128:541 128:541 8192.0019e25051e0 1000 FWD DESG
ge-0/0/24 128:537 128:537 8192.0019e25051e0 1000 FWD DESG
Meaning
The operational mode command show spanning-tree interface shows that no interface is the root interface.
Verifying RSTP Configuration on Switch 4
Purpose
Use this procedure to verify the RSTP configuration on both Switch 4 Routing Engines.
Action
Use the operational mode commands:
user@switch4> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/23 128:536 128:536 8192.0019e25051e0 1000 FWD ROOT
ge-0/0/19 128:532 128:532 16384.0019e25040e0 1000 FWD DESG
Meaning
The operational mode command show spanning-tree interface shows that interface ge-0/0/23 is the root interface and forwarding.
Example: Faster Convergence and Improved Network Stability with RSTP on EX Series Switches
EX Series switches use Rapid Spanning Tree Protocol (RSTP) by default to provide a loop-free topology.
When switches that support redundant Routing Engines use RSTP, it is important to keep RSTP synchronized on both Routing Engines so that no loss of service occurs after a Routing Engine switchover. Nonstop bridging protocol keeps Routing Engines synchronized.
This example describes how to configure RSTP and NSB on four EX Series switches:
Requirements
This example uses the following hardware and software components:
Junos OS Release 11.3 or later for EX Series switches
Four EX Series switches
Before you configure the switches for RSTP, be sure you have:
Installed the four switches. See Connecting and Configuring an EX Series Switch (J-Web Procedure).
Performed the initial software configuration on all switches. See Unresolved topic-ref: "130557".
Overview and Topology
RSTP works by identifying certain links as point to point links and blocking other possible paths. When one of the point-to-point links fails, a designated alternate link transitions to the forwarding state and take over. Configuring nonstop bridging (NSB) on a switch with redundant Routing Engines keeps RSTP synchronized on both Routing Engines. This way, RSTP remains active immediately after a switchover because it is already synchronized to the backup Routing Engine. RSTP does not have to reconverge after a Routing Engine switchover when NSB is enabled because the neighbor devices do not detect an RSTP change on the switch. In this example, four EX Series switches are connected in the topology displayed in Figure 2 to create a loop-free topology with NSB applied to switches with dual Routing Engines.
Table 2 shows the components of the topology for this example.
You can configure RSTP on logical or physical interfaces. This example shows RSTP configured on logical interfaces.
Table 2: Components of the Topology for Configuring RSTP
Property | Settings |
|---|---|
Switch 1 | The following interfaces on Switch 1 are connected in this way:
|
Switch 2 | The following interfaces on Switch 2 are connected in this way:
|
Switch 3 | The following interfaces on Switch 3 are connected in this way:
|
Switch 4 | The following interfaces on Switch 4 are connected in this way:
|
VLAN names and tag IDs | voice-vlan,
tag 10 |
This configuration example creates a loop-free topology between four EX Series switches using RSTP.
An RSTP topology contains ports that have specific roles:
The root port is responsible for forwarding data to the root bridge.
The alternate port is a standby port for the root port. When a root port goes down, the alternate port becomes the active root port.
The designated port forwards data to the downstream network segment or device.
The backup port is a backup port for the designated port. When a designated port goes down, the backup port becomes the active designated port and starts forwarding data.
You also can create a loop-free topology between the aggregation layer and the distribution layer using redundant trunk links. For more information about configuring redundant trunk links, see Example: Configuring Redundant Trunk Links for Faster Recovery on EX Series Switches.
Configuring RSTP and Nonstop Bridging on Switch 1
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 1, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/13
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge–0/0/9
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge–0/0/11
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge–0/0/13
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/9
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/11
unit 0 family ethernet-switching port-mode trunk
set protocols rstp
bridge-priority 16k set protocols rstp
interface ge-0/0/13.0 cost 1000 set protocols rstp
interface ge-0/0/13.0 mode point-to-point
set protocols rstp
interface ge-0/0/9.0 cost 1000 set protocols rstp
interface ge-0/0/9.0 mode point-to-point
set protocols rstp
interface ge-0/0/11.0 cost 1000 set protocols rstp
interface ge-0/0/11.0 mode point-to-point
If Switch 1 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 1, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset ethernet-switching-options nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 1:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch1# set voice-vlan description “Voice VLAN”
user@switch1# set voice-vlan vlan-id 10
user@switch1# set employee-vlan description “Employee VLAN”
user@switch1# set employee-vlan vlan-id 20
user@switch1# set guest-vlan description “Guest VLAN”
user@switch1# set guest-vlan vlan-id 30
user@switch1# set camera-vlan description “Camera VLAN”
user@switch1# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch1# set ge-0/0/13 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch1# set ge-0/0/9 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch1# set ge-0/0/11 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch1# set ge-0/0/13 unit 0 family ethernet-switching port-mode trunk
user@switch1# set ge-0/0/9 unit 0 family ethernet-switching port-mode trunk
user@switch1# set ge-0/0/11 unit 0 family ethernet-switching port-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch1# rstp bridge-priority 16k
user@switch1# rstp interface ge-0/0/13.0 cost 1000
user@switch1# rstp interface ge-0/0/13.0 mode point-to-point
user@switch1# rstp interface ge-0/0/9.0 cost 1000
user@switch1# rstp interface ge-0/0/9.0 mode point-to-point
user@switch1# rstp interface ge-0/0/11.0 cost 1000
user@switch1# rstp interface ge-0/0/11.0 mode point-to-point
Step-by-Step Procedure
If Switch 1 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 1:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch1# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch1# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit ethernet-switching-options]
user@switch1# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 2
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 2, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/14
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/18
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/14
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/18
unit 0 family ethernet-switching port-mode trunk
set protocols rstp
bridge-priority 32k set protocols rstp
interface ge-0/0/14.0 cost 1000 set protocols rstp
interface ge-0/0/14.0 mode point-to-point
set protocols rstp
interface ge-0/0/18.0 cost 1000 set protocols rstp
interface ge-0/0/18.0 mode point-to-point
If Switch 2 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 2, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset ethernet-switching-options nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 2:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch2# set voice-vlan description “Voice VLAN”
user@switch2# set voice-vlan vlan-id 10
user@switch2# set employee-vlan description “Employee VLAN”
user@switch2# set employee-vlan vlan-id 20
user@switch2# set guest-vlan description “Guest VLAN”
user@switch2# set guest-vlan vlan-id 30
user@switch2# set camera-vlan vlan-description “Camera VLAN”
user@switch2# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch2# set ge-0/0/14 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch2# set ge-0/0/18 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch2# set ge-0/0/14 unit 0 family ethernet-switching port-mode trunk
user@switch2# set ge-0/0/18 unit 0 family ethernet-switching port-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch2# rstp bridge-priority 32k
user@switch2# rstp interface ge-0/0/14.0 cost 1000
user@switch2# rstp interface ge-0/0/14.0 mode point-to-point
user@switch2# rstp interface ge-0/0/18.0 cost 1000
user@switch2# rstp interface ge-0/0/18.0 mode point-to-point
Step-by-Step Procedure
If Switch 2 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 2:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch2# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch2# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit ethernet-switching-options]
user@switch2# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 3
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 3, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan-id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/26
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/28
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/24
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/26
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/28
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/24
unit 0 family ethernet-switching port-mode trunk
set protocols rstp
bridge-priority 8k set protocols rstp
interface ge-0/0/26.0 cost 1000 set protocols rstp
interface ge-0/0/26.0 mode point-to-point
set protocols rstp
interface ge-0/0/28.0 cost 1000 set protocols rstp
interface ge-0/0/28.0 mode point-to-point
set protocols rstp
interface ge-0/0/24.0 cost 1000 set protocols rstp
interface ge-0/0/24.0 mode point-to-point
If Switch 3 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 3, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset ethernet-switching-options nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 3:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch3# set voice-vlan description “Voice VLAN”
user@switch3# set voice-vlan vlan-id 10
user@switch3# set employee-vlan description “Employee VLAN”
user@switch3# set employee-vlan vlan-id 20
user@switch3# set guest-vlan description “Guest VLAN”
user@switch3# set guest-vlan vlan-id 30
user@switch3# set camera-vlan description “Camera VLAN”
user@switch3# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch3# set ge-0/0/26 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch3# set ge-0/0/28 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch3# set ge-0/0/24 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch3# set ge-0/0/26 unit 0 family ethernet-switching port-mode trunk
user@switch3# set ge-0/0/28 unit 0 family ethernet-switching port-mode trunk
user@switch3# set ge-0/0/24 unit 0 family ethernet-switching port-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch3# rstp bridge-priority 8k
user@switch3# rstp interface ge-0/0/26.0 cost 1000
user@switch3# rstp interface ge-0/0/26.0 mode point-to-point
user@switch3# rstp interface ge-0/0/28.0 cost 1000
user@switch3# rstp interface ge-0/0/28.0 mode point-to-point
user@switch3# rstp interface ge-0/0/24.0 cost 1000
user@switch3# rstp interface ge-0/0/24.0 mode point-to-point
Step-by-Step Procedure
If Switch 3 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 3:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch3# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch3# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit ethernet-switching-options]
user@switch3# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Configuring RSTP and Nonstop Bridging on Switch 4
CLI Quick Configuration
To quickly configure RSTP and nonstop bridging on Switch 4, copy the following commands and paste them into the switch terminal window:
[edit] set vlans voice-vlan
description “Voice VLAN”
set vlans voice-vlan
vlan–id 10 set vlans employee-vlan
description “Employee VLAN”
set vlans employee-vlan
vlan-id 20 set vlans guest-vlan
description “Guest VLAN”
set vlans guest-vlan
vlan-id 30 set vlans camera-vlan
description “Camera VLAN”
set vlans camera-vlan
vlan-id 40 set interfaces ge-0/0/23
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/19
unit 0 family ethernet-switching vlan members [10 20 30 40] set interfaces ge-0/0/23
unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/19
unit 0 family ethernet-switching port-mode trunk
set protocols rstp
bridge-priority 16k set protocols rstp
interface ge-0/0/23.0 cost 1000 set protocols rstp
interface ge-0/0/23.0 mode point-to-point
set protocols rstp
interface ge-0/0/19.0 cost 1000 set protocols rstp
interface ge-0/0/19.0 mode point-to-point
If Switch 4 includes dual Routing Engines, configure NSB. To quickly configure nonstop bridging on Switch 4, copy the following commands and paste them into the switch terminal window:
set chassis redundancy graceful switchoverset system commit synchronizeset ethernet-switching-options nonstop-bridgingStep-by-Step Procedure
To configure RSTP and nonstop bridging on Switch 4:
- Configure the VLANs voice-vlan, employee-vlan, guest-vlan, and camera-vlan:
[edit vlans]
user@switch4# set voice-vlan description “Voice VLAN”
user@switch4# set voice-vlan vlan-id 10
user@switch4# set employee-vlan description “Employee VLAN”
user@switch4# set employee-vlan vlan-id 20
user@switch4# set guest-vlan description “Guest VLAN”
user@switch4# set guest-vlan vlan-id 30
user@switch4# set camera-vlan description “Camera VLAN”
user@switch4# set camera-vlan vlan-id 40
- Configure the VLANs on the interfaces, including support
for the Ethernet switching protocol:
[edit interfaces]
user@switch4# set ge-0/0/23 unit 0 family ethernet-switching vlan members [10 20 30 40]
user@switch4# set ge-0/0/19 unit 0 family ethernet-switching vlan members [10 20 30 40]
- Configure the port mode for the interfaces:
[edit interfaces]
user@switch4# set ge-0/0/23 unit 0 family ethernet-switching port-mode trunk
user@switch4# set ge-0/0/19 unit 0 family ethernet-switching port-mode trunk - Configure RSTP on the switch:
[edit protocols]
user@switch4# rstp bridge-priority 16k
user@switch4# rstp interface all cost 1000
user@switch4# rstp interface ge-0/0/23.0 cost 1000
user@switch4# rstp interface ge-0/0/23.0 mode point-to-point
user@switch4# rstp interface ge-0/0/19.0 cost 1000
user@switch4# rstp interface ge-0/0/19.0 mode point-to-point
Step-by-Step Procedure
If Switch 4 includes dual Routing Engines, configure nonstop bridging. To configure NSB on Switch 4:
- Enable graceful Routing Engine switchover (GRES):
[edit chassis redundancy]
user@switch4# set graceful-switchover - Configure the switch to always synchronize configuration
changes between the Routing Engines:
[edit system]
user@switch4# set commit synchronizeIf you try to commit a configuration in which nonstop bridging is configured but synchronization of configuration changes is not configured, the configuration is not committed.
- Enable nonstop bridging:
[edit ethernet-switching-options]
user@switch4# set nonstop-bridgingNote This process enables NSB for all NSB-supported Layer 2 protocols on the switch, including RSTP.
Results
Check the results of the configuration:
Verification
To confirm that the configuration is working properly, perform these tasks on both Routing Engines:
Verifying RSTP Configuration on Switch 1
Purpose
Verify the RSTP configuration on Switch 1.
Action
Use the operational mode command:
user@switch1> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/13.0 128:526 128:526 16384.0019e25040e0 1000 BLK ALT
ge-0/0/9.0 128:522 128:522 32768.0019e2503d20 1000 BLK ALT
ge-0/0/11.0 128:524 128:524 8192.0019e25051e0 1000 FWD ROOT
Meaning
The operational mode command show spanning-tree interface shows that ge-0/0/13.0 is in a forwarding state. The other interfaces on Switch 1 are blocking.
Verifying RSTP Configuration on Switch 2
Purpose
Use this procedure to verify the RSTP configuration on both Switch 2 Routing Engines.
Action
Use the operational mode command:
user@switch2> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/14.0 128:527 128:527 32768.0019e2503d20 1000 FWD DESG
ge-0/0/18.0 128:529 128:529 8192.0019e25051e0 1000 FWD ROOT
Meaning
The operational mode command show spanning-tree interface shows that ge-0/0/18.0 is in a forwarding state and is the root port.
Verifying RSTP Configuration on Switch 3
Purpose
Use this procedure to verify the RSTP configuration on both Switch 3 Routing Engines.
Action
Use the operational mode commands:
user@switch3> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/26.0 128:539 128:539 8192.0019e25051e0 1000 FWD DESG
ge-0/0/28.0 128:541 128:541 8192.0019e25051e0 1000 FWD DESG
ge-0/0/24.0 128:537 128:537 8192.0019e25051e0 1000 FWD DESG
Meaning
The operational mode command show spanning-tree interface shows that no interface is the root interface.
Verifying RSTP Configuration on Switch 4
Purpose
Use this procedure to verify the RSTP configuration on both Switch 4 Routing Engines.
Action
Use the operational mode commands:
user@switch4> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/23.0 128:536 128:536 8192.0019e25051e0 1000 FWD ROOT
ge-0/0/19.0 128:532 128:532 16384.0019e25040e0 1000 FWD DESG
Meaning
The operational mode command show spanning-tree interface shows that interface ge-0/0/23.0 is the root interface and forwarding.
Forcing RSTP or VSTP to Run as IEEE 802.1D STP (CLI Procedure)
This procedure uses Junos OS for EX Series switches with support for the Enhanced Layer 2 Software (ELS) configuration style. For ELS details, see Using the Enhanced Layer 2 Software CLI.
On EX Series switches running Rapid Spanning Tree Protocol (RSTP) (the default) or VLAN Spanning Tree Protocol (VSTP), you can force the original IEEE 802.1D Spanning Tree Protocol (STP) version to run in place of RSTP or VSTP. Configure the force-version stp statement for compatibility with older bridges that do not support RSTP or VSTP.
To force the spanning-tree protocol version to be the original IEEE 802.1D STP:
- Enable IEEE 802.1D STP:
[edit protocols]
user@switch# set (rstp | vstp) force-version stp
After using the force-version statement to enable xSTP globally, apply the force-version statement for specific Layer 2 ports.