Juniper Networks :: Technical Documentation :: Example: Configuring Network Regions for VLANs with MSTP on EX-series Switches

Juniper was the first North American IP routing vendor to achieve the prestigious TL 9000 certification by the Quality of Excellence for Suppliers of Telecommunications (QuEST) Forum in the router category, for design, development, provision and service and support.

What is J-Care?

It's the world-class service and support that you expect from a company that delivers the industry's best infrastructure and security products. With J-Care, you now have the confidence knowing that Juniper will do our part to keep you on top of the world!

Download PDFs
Example: Configuring Network Regions for VLANs with MSTP on EX-series Switches

Example: Configuring Network Regions for VLANs with MSTP on EX-series Switches

Multiple Spanning Tree Protocol (MSTP) is used to create a loop-free topology in networks using multiple spanning tree regions, each region containing multiple spanning-tree instances (MSTIs). MSTIs provide different paths for different VLANs. This functionality facilitates better load sharing across redundant links.

MSTP supports up to 64 regions, each one capable of supporting 4094 MSTIs.

This example describes how to configure MSTP on four EX-series switches:

Requirements

This example uses the following hardware and software components:

JUNOS Release 9.0 or later for EX-series switches
Four EX-series switches

Before you configure the switches for MSTP, be sure you have:

Installed the four switches. See Connecting and Configuring the EX-series Switch (J-Web Procedure).
Performed the initial software configuration on all switches. See Installing and Connecting an EX-series Switch.

Overview and Topology

When the number of VLANs grows in a network, MSTP provides a more efficient way of creating a loop-free topology using MSTIs. Each MSTI in the spanning tree domain maintains its own tree. Each tree can be mapped to different links, utilizing bandwidth that would be unavailable to a single tree. MSTIs reduce demand on system resources.

Figure 1: Network Topology for MSTP

Image g020032.gif

The interfaces shown in Table 1 will be configured for MSTP.

Table 1: Components of the Topology for Configuring MSTP on EX-series Switches

Property	Settings
Switch 1	The following ports on Switch 1 are connected in this way: ge-0/0/9 is connected to Switch 2 ge-0/0/13 is connected to Switch 4 ge-0/0/11 is connected to Switch 3
Switch 2	The following ports on Switch 2 are connected in this way: ge-0/0/14 is connected to Switch 1 ge-0/0/18 is connected to Switch 3
Switch 3	The following ports on Switch 3 are connected in this way: ge-0/0/26 is connected to Switch 1 ge-0/0/28 is connected to Switch 2 ge-0/0/24 is connected to Switch 4
Switch 4	The following ports on Switch 4 are connected in this way: ge-0/0/19 is connected to Switch 1 ge-0/0/23 is connected to Switch 3
VLAN names and tag IDs	voice-vlan, tag 10 employee-vlan, tag 20 guest-vlan, tag 30 camera-vlan, tag 40
MSTIs	1 2

The topology in Figure 1 shows a Common Internal Spanning Tree (CIST). The CIST is a single spanning tree connecting all devices in the network. The switch with the highest priority is elected as the root bridge of the CIST.

Also in an MSTP topology are 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.

In this example, one MSTP region, region1, contains Switch 1, Switch 2, Switch 3, and Switch 4. Within the region, four VLANs are created:

The voice-vlan supports voice traffic and has a VLAN tag identifier of 10.
employee-vlan supports data traffic and has a VLAN tag identifier of 20.
The guest-vlan supports guest VLAN traffic (for supplicants that fail 802-1X authentication) and has a VLAN tag identifier of 30.
The camera-vlan supports video traffic and has a VLAN tag identifier of 40.

The VLANs are associated with specific interfaces on each of the four switches. Two MSTIs, 1 and 2, are then associated with the VLAN tag identifiers, and some MSTP parameters, such as cost, are configured on each switch.

Configuring MSTP on Switch 1

To configure MSTP on Switch 1, perform these tasks:

CLI Quick Configuration

To quickly configure interfaces and MSTP 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 mstp configuration-name region1

set protocols mstp bridge-priority 16k

set protocols mstp interface ge-0/0/13.0 cost
1000

set protocols mstp interface ge-0/0/13.0 mode
point-to-point

set protocols mstp interface ge-0/0/9.0 cost
1000

set protocols mstp interface ge-0/0/9.0 mode
point-to-point

set protocols mstp interface ge-0/0/11.0 cost
1000

set protocols mstp interface ge-0/0/11.0 mode
point-to-point

set protocols mstp msti 1 bridge-priority 16k

set protocols mstp msti 1 vlan [10 20]

set protocols mstp msti 1 interface ge-0/0/11.0
cost 4000

set protocols mstp msti 2 bridge-priority 8k

set protocols mstp msti 2 vlan [30 40]

Step-by-Step Procedure

To configure interfaces and MSTP 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 guest-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 MSTP on the switch, including the two MSTIs:
[edit protocols] user@switch1# mstp configuration-name region1 user@switch1# mstp bridge-priority 16k user@switch1# mstp interface ge-0/0/13.0 cost 1000 user@switch1# mstp interface ge-0/0/13.0 mode point-to-point user@switch1# mstp interface ge-0/0/9.0 cost 1000 user@switch1# mstp interface ge-0/0/9.0 mode point-to-point user@switch1# mstp interface ge-0/0/11.0 cost 4000 user@switch1# mstp interface ge-0/0/11.0 mode point-to-point user@switch1# mstp msti 1 bridge-priority 16k user@switch1# mstp msti 1 vlan [10 20] user@switch1# mstp msti 1 interface ge-0/0/11.0 cost 4000 user@switch1# mstp msti 2 bridge-priority 8k user@switch1# mstp msti 2 vlan [30 40]

Results

Check the results of the configuration:



user@switch1> show configuration

interfaces {


ge-0/0/13 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/9 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/11 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}


}
protocols {


mstp {
configuration-name region1;
bridge-priority 16k;


interface ge-0/0/13.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/9.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/11.0 {
cost 4000;
mode point-to-point;
}






msti 1 {
bridge-priority 16k;
vlan [ 10 20 ];


interface ge-0/0/11.0 {
cost 4000;
}


}




msti 2 {
bridge-priority 8k;
vlan [ 30 40 ];
}


}
vlans {


voice-vlan {
vlan-id 10;
}




employee-vlan {
vlan-id 20;
}




guest-vlan {
vlan-id 30;
}




camera-vlan {
vlan-id 40;
}


}

Configuring MSTP on Switch 2

To configure on Switch 2, perform these tasks:

CLI Quick Configuration

To quickly configure interfaces and MSTP 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 mstp configuration-name region1

set protocols mstp bridge-priority 32k

set protocols mstp interface ge-0/0/14.0 cost
1000

set protocols mstp interface ge-0/0/14.0 mode
point-to-point

set protocols mstp interface ge-0/0/18.0 cost
1000

set protocols mstp interface ge-0/0/18.0 mode
point-to-point

set protocols mstp msti 1 bridge-priority 32k

set protocols mstp msti 1 vlan [10 20]

set protocols mstp msti 2 bridge-priority 4k

set protocols mstp msti 2 vlan [30 40]

Step-by-Step Procedure

To configure interfaces and MSTP 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 guest-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 MSTP on the switch, including the two MSTIs:
[edit protocols] user@switch2# mstp configuration-name region1 user@switch2# mstp bridge-priority 32k user@switch2# mstp interface ge-0/0/14.0 cost 1000 user@switch2# mstp interface ge-0/0/14.0 mode point-to-point user@switch2# mstp interface ge-0/0/18.0 cost 1000 user@switch2# mstp interface ge-0/0/18.0 mode point-to-point user@switch2# mstp interface all cost 1000 user@switch2# mstp msti 1 bridge-priority 32k user@switch2# mstp msti 1 vlan [10 20] user@switch2# mstp msti 2 bridge-priority 4k user@switch2# mstp msti 2 vlan [30 40]

Results

Check the results of the configuration:



user@switch2> show configuration

interfaces {


ge-0/0/14 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/18 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}


}
protocols {


mstp {
configuration-name region1;
bridge-priority 32k;


interface ge-0/0/14.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/18.0 {
cost 1000;
mode point-to-point;
}




msti 1 {
bridge-priority 32k;
vlan [ 10 20 ];
}




msti 2 {
bridge-priority 4k;
vlan [ 30 40 ];
}


}


}
vlans {


voice-vlan {
vlan-id 10;
}




employee-vlan {
vlan-id 20;
}




guest-vlan {
vlan-id 30;
}




camera-vlan {
vlan-id 40;
}


}

Configuring MSTP on Switch 3

To configure MSTP on Switch 3, perform these tasks:

CLI Quick Configuration

To quickly configure interfaces and MSTP 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 mstp configuration-name region1

set protocols mstp bridge-priority 8k

set protocols mstp interface ge-0/0/26.0 cost
1000

set protocols mstp interface ge-0/0/26.0 mode
point-to-point

set protocols mstp interface ge-0/0/28.0 cost
1000

set protocols mstp interface ge-0/0/28.0 mode
point-to-point

set protocols mstp interface ge-0/0/24.0 cost
1000

set protocols mstp interface ge-0/0/24.0 mode
point-to-point

set protocols mstp msti 1 bridge-priority 4k

set protocols mstp msti 1 vlan [10 20]

set protocols mstp msti 2 bridge-priority 16k

set protocols mstp msti 2 vlan [30 40]

Step-by-Step Procedure

To configure interfaces and MSTP 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 guest-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 MSTP on the switch, including the two MSTIs:
[edit protocols] user@switch3# mstp configuration-name region1 user@switch3# mstp bridge-priority 8k user@switch3# mstp interface ge-0/0/26.0 cost 1000 user@switch3# mstp interface ge-0/0/26.0 mode point-to-point user@switch3# mstp interface ge-0/0/28.0 cost 1000 user@switch3# mstp interface ge-0/0/28.0 mode point-to-point user@switch3# mstp interface ge-0/0/24.0 cost 1000 user@switch3# mstp interface ge-0/0/24.0 mode point-to-point user@switch3# mstp interface all cost 1000 user@switch3# mstp msti 1 bridge-priority 4k user@switch3# mstp msti 1 vlan [10 20] user@switch3# mstp msti 2 bridge-priority 16k user@switch3# mstp msti 2 vlan [30 40]

Results

Check the results of the configuration:



user@switch3> show configuration



interfaces {


ge-0/0/26 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/28 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/24 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}


}


}
protocols {


mstp {
configuration-name region1;
bridge-priority 8k;


interface ge-0/0/26.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/28.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/24.0 {
cost 1000;
mode point-to-point;
}




msti 1 {
bridge-priority 4k;
vlan [ 10 20 ];
}




msti 2 {
bridge-priority 16k;
vlan [ 30 40 ];
}


}


}
vlans {


voice-vlan {
vlan-id 10;
}




employee-vlan {
vlan-id 20;
}




guest-vlan {
vlan-id 30;
}




camera-vlan {
vlan-id 40;
}


}

Configuring MSTP on Switch 4

To configure MSTP on Switch 4, perform these tasks:

CLI Quick Configuration

To quickly configure interfaces and MSTP 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 mstp configuration-name region1

set protocols mstp bridge-priority 16k

set protocols mstp interface ge—0/0/23.0
cost 1000

set protocols mstp interface ge—0/0/23.0
mode point-to-point

set protocols mstp interface ge—0/0/19.0
cost 1000

set protocols mstp interface ge—0/0/19.0
mode point-to-point

set protocols mstp msti 1 bridge-priority 16k

set protocols mstp msti 1 vlan [10 20]

set protocols mstp msti 2 bridge-priority 32k

set protocols mstp msti 2 vlan [30 40]

Step-by-Step Procedure

To configure interfaces and MSTP 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 guest-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 MSTP on the switch, including the two MSTIs:
[edit protocols] user@switch4# mstp configuration-name region1 user@switch4# mstp bridge-priority 16k user@switch4# mstp interface all cost 1000 user@switch4# mstp interface ge—0/0/23.0 cost 1000 user@switch4# mstp interface ge—0/0/23.0 mode point-to-point user@switch4# mstp interface ge—0/0/19.0 cost 1000 user@switch4# mstp interface ge—0/0/19.0 mode point-to-point user@switch4# mstp msti 1 bridge-priority 16k user@switch4# mstp msti 1 vlan [10 20] user@switch4# mstp msti 2 bridge-priority 32k user@switch4# mstp msti 2 vlan [30 40]

Results

Check the results of the configuration:



user@switch4> show configuration

interfaces {


ge-0/0/23 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}




ge-0/0/19 {


unit 0 {


family ethernet-switching {
port-mode trunk;


vlan {
members 10;
members 20;
members 30;
members 40;
}


}


}


}


}
protocols {


mstp {
configuration-name region1;
bridge-priority 16k;


interface ge-0/0/23.0 {
cost 1000;
mode point-to-point;
}




interface ge-0/0/19.0 {
cost 1000;
mode point-to-point;
}




msti 1 {
bridge-priority 16k;
vlan [ 10 20 ];
}




msti 2 {
bridge-priority 32k;
vlan [ 30 40 ];
}


}


}
vlans {


voice-vlan {
vlan-id 10;
}




employee-vlan {
vlan-id 20;
}




guest-vlan {
vlan-id 30;
}




camera-vlan {
vlan-id 40;
}


}

Verification

To confirm that the configuration is working properly, perform these tasks:

Verifying MSTP Configuration on Switch 1

Purpose

Verify the MSTP configuration on Switch 1.

Action

Use the operational mode commands:

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    128:527      128:525  16384.0019e25040e0      1000  FWD    ROOT 
ge-0/0/9.0     128:529      128:513  32768.0019e2503d20      1000  BLK    ALT  
ge-0/0/11.0    128:531      128:513   8192.0019e25051e0      4000  BLK    ALT  

Spanning tree interface parameters for instance 1

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/13.0    128:527      128:525  16385.0019e25040e0      1000  FWD    ROOT 
ge-0/0/9.0     128:529      128:513  32769.0019e2503d20      1000  BLK    ALT  
ge-0/0/11.0    128:531      128:513   4097.0019e25051e0      4000  BLK    ALT  

Spanning tree interface parameters for instance 2

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/13.0    128:527      128:527   8194.0019e25044e0      1000  FWD    DESG 
ge-0/0/9.0     128:529      128:513   4098.0019e2503d20      1000  FWD    ROOT 
ge-0/0/11.0    128:531      128:531   8194.0019e25044e0      1000  FWD    DESG

user@switch1> show spanning-tree bridge

STP bridge parameters 
Context ID                          : 0
Enabled protocol                    : MSTP

STP bridge parameters for CIST
  Root ID                           : 8192.00:19:e2:50:51:e0
  Root cost                         : 0
  Root port                         : ge-0/0/13.0
  CIST regional root                : 8192.00:19:e2:50:51:e0
  CIST internal root cost           : 2000
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 18 
  Message age                       : 0 
  Number of topology changes        : 3
  Time since last topology change   : 921 seconds
  Local parameters 
    Bridge ID                       : 16384.00:19:e2:50:44:e0
    Extended system ID              : 0
    Internal instance ID            : 0

STP bridge parameters for MSTI 1
  MSTI regional root                : 4097.00:19:e2:50:51:e0
  Root cost                         : 2000
  Root port                         : ge-0/0/13.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 18 
  Local parameters 
    Bridge ID                       : 16385.00:19:e2:50:44:e0
    Extended system ID              : 0
    Internal instance ID            : 1

STP bridge parameters for MSTI 2
  MSTI regional root                : 4098.00:19:e2:50:3d:20
  Root cost                         : 1000
  Root port                         : ge-0/0/9.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Local parameters 
    Bridge ID                       : 8194.00:19:e2:50:44:e0
    Extended system ID              : 0
    Internal instance ID            : 2

Meaning

The operational mode command show spanning-tree interface displays spanning-tree domain information such as the designated port and the port roles.

The operational mode command show spanning-tree bridge displays the spanning-tree domain information at either the bridge level or interface level. If the optional interface name is omitted, all interfaces in the spanning-tree domain are displayed.

Verifying MSTP Configuration on Switch 2

Purpose

Verify the MSTP configuration on Switch 2.

Action

Use the operational mode commands:

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     128:513      128:513  32768.0019e2503d20      1000  FWD    DESG 
ge-0/0/18.0     128:519      128:515   8192.0019e25051e0      1000  FWD    ROOT 

Spanning tree interface parameters for instance 1

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/14.0     128:513      128:513  32769.0019e2503d20      1000  FWD    DESG 
ge-0/0/18.0     128:519      128:515   4097.0019e25051e0      1000  FWD    ROOT 

Spanning tree interface parameters for instance 2

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/14.0     128:513      128:513   4098.0019e2503d20      1000  FWD    DESG   
ge-0/0/18.0     128:519      128:519   4098.0019e2503d20      1000  FWD    DESG

user@switch2> show spanning-tree bridge

STP bridge parameters 
Context ID                          : 0
Enabled protocol                    : MSTP

STP bridge parameters for CIST
  Root ID                           : 8192.00:19:e2:50:51:e0
  Root cost                         : 0
  Root port                         : ge-0/0/18.0
  CIST regional root                : 8192.00:19:e2:50:51:e0
  CIST internal root cost           : 1000
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Message age                       : 0 
  Number of topology changes        : 1
  Time since last topology change   : 782 seconds
  Local parameters 
    Bridge ID                       : 32768.00:19:e2:50:3d:20
    Extended system ID              : 0
    Internal instance ID            : 0

STP bridge parameters for MSTI 1
  MSTI regional root                : 4097.00:19:e2:50:51:e0
  Root cost                         : 1000
  Root port                         : ge-0/0/18.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Local parameters 
    Bridge ID                       : 32769.00:19:e2:50:3d:20
    Extended system ID              : 0
    Internal instance ID            : 1

STP bridge parameters for MSTI 2
  MSTI regional root                : 4098.00:19:e2:50:3d:20
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Local parameters 
    Bridge ID                       : 4098.00:19:e2:50:3d:20
    Extended system ID              : 0
    Internal instance ID            : 2

Meaning

The operational mode command show spanning-tree interface displays spanning-tree domain information such as the designated port and the port roles.

Verifying MSTP Configuration on Switch 3

Purpose

Verify the MSTP configuration on Switch 3.

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     128:513      128:513   8192.0019e25051e0      1000  FWD    DESG 
ge-0/0/28.0     128:515      128:515   8192.0019e25051e0      1000  FWD    DESG 
ge-0/0/24.0     128:517      128:517   8192.0019e25051e0      1000  FWD    DESG 

Spanning tree interface parameters for instance 1

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/26.0     128:513      128:513   4097.0019e25051e0      1000  FWD    DESG 
ge-0/0/28.0     128:515      128:515   4097.0019e25051e0      1000  FWD    DESG 
ge-0/0/24.0     128:517      128:517   4097.0019e25051e0      1000  FWD    DESG  

Spanning tree interface parameters for instance 2

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/26.0     128:513      128:531   8194.0019e25044e0      1000  BLK    ALT  
ge-0/0/28.0     128:515      128:519   4098.0019e2503d20      1000  FWD    ROOT 
ge-0/0/24.0     128:517      128:517  16386.0019e25051e0      1000  FWD    DESG

user@switch3> show spanning-tree bridge

STP bridge parameters 
Context ID                          : 0
Enabled protocol                    : MSTP

STP bridge parameters for CIST
  Root ID                           : 8192.00:19:e2:50:51:e0
  CIST regional root                : 8192.00:19:e2:50:51:e0
  CIST internal root cost           : 0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Number of topology changes        : 3
  Time since last topology change   : 843 seconds
  Local parameters 
    Bridge ID                       : 8192.00:19:e2:50:51:e0
    Extended system ID              : 0
    Internal instance ID            : 0

STP bridge parameters for MSTI 1
  MSTI regional root                : 4097.00:19:e2:50:51:e0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Local parameters  
    Bridge ID                       : 4097.00:19:e2:50:51:e0
    Extended system ID              : 0
    Internal instance ID            : 1

STP bridge parameters for MSTI 2
  MSTI regional root                : 4098.00:19:e2:50:3d:20
  Root cost                         : 1000
  Root port                         : ge-0/0/28.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Local parameters 
    Bridge ID                       : 16386.00:19:e2:50:51:e0
    Extended system ID              : 0
    Internal instance ID            : 2

Meaning

The operational mode command show spanning-tree interface displays spanning-tree domain information such as the designated port and the port roles.

Verifying MSTP Configuration on Switch 4

Purpose

Verify the MSTP configuration on Switch 4.

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    128:523      128:517   8192.0019e25051e0      1000  FWD    ROOT 
ge-0/0/19.0    128:525      128:525  16384.0019e25040e0      1000  FWD    DESG 

Spanning tree interface parameters for instance 1

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost 
ge-0/0/23.0    128:523      128:517   4097.0019e25051e0      1000  FWD    ROOT 
ge-0/0/19.0    128:525      128:525  16385.0019e25040e0      1000  FWD    DESG 


Spanning tree interface parameters for instance 2

Interface    Port ID    Designated      Designated         Port    State  Role
                         port ID        bridge ID          Cost
ge-0/0/23.0    128:523      128:517  16386.0019e25051e0      1000  BLK    ALT  
ge-0/0/19.0    128:525      128:527   8194.0019e25044e0      1000  FWD    ROOT

user@switch4> show spanning-tree bridge

STP bridge parameters 
Context ID                          : 0
Enabled protocol                    : MSTP

STP bridge parameters for CIST
  Root ID                           : 8192.00:19:e2:50:51:e0
  Root cost                         : 0
  Root port                         : ge-0/0/23.0
  CIST regional root                : 8192.00:19:e2:50:51:e0
  CIST internal root cost           : 1000
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Message age                       : 0 
  Number of topology changes        : 4
  Time since last topology change   : 887 seconds
  Local parameters 
    Bridge ID                       : 16384.00:19:e2:50:40:e0
    Extended system ID              : 0
    Internal instance ID            : 0

STP bridge parameters for MSTI 1
  MSTI regional root                : 4097.00:19:e2:50:51:e0
  Root cost                         : 1000
  Root port                         : ge-0/0/23.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 19 
  Local parameters 
    Bridge ID                       : 16385.00:19:e2:50:40:e0
    Extended system ID              : 0
    Internal instance ID            : 1

STP bridge parameters for MSTI 2
  MSTI regional root                : 4098.00:19:e2:50:3d:20
  Root cost                         : 2000
  Root port                         : ge-0/0/19.0
  Hello time                        : 2 seconds
  Maximum age                       : 20 seconds
  Forward delay                     : 15 seconds
  Hop count                         : 18 
  Local parameters 
    Bridge ID                       : 32770.00:19:e2:50:40:e0
    Extended system ID              : 0
    Internal instance ID            : 2

Meaning

The operational mode command show spanning-tree interface displays spanning-tree domain information such as the designated port and the port roles.

Support

Example: Configuring Network Regions for VLANs with MSTP on EX-series Switches

Requirements

Overview and Topology

Configuring MSTP on Switch 1

CLI Quick Configuration

Step-by-Step Procedure

Results

Configuring MSTP on Switch 2

CLI Quick Configuration

Step-by-Step Procedure

Results

Configuring MSTP on Switch 3

CLI Quick Configuration

Step-by-Step Procedure

Results

Configuring MSTP on Switch 4

CLI Quick Configuration

Step-by-Step Procedure

Results

Verification

Verifying MSTP Configuration on Switch 1

Purpose

Action

Meaning

Verifying MSTP Configuration on Switch 2

Purpose

Action

Meaning

Verifying MSTP Configuration on Switch 3

Purpose

Action

Meaning

Verifying MSTP Configuration on Switch 4

Purpose

Action

Meaning