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    Example: Configuring Network Regions for VLANs with MSTP

    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 more efficient load sharing across redundant links.

    You can create up to 64 MSTI instances for QFX Series products, and each MSTI supports up to 4094 VLANs.

    This example describes how to configure MSTP on four QFX3500 switches:

    Requirements

    This example uses the following hardware and software components:

    • Junos OS Release 11.1 for the QFX3500 switches
    • Four QFX3500 switches

    Overview and Topology

    When the number of VLANs grows in a network, MSTP provides a more faster 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

    Network Topology for MSTP

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

    Note: You can configure MSTP on logical or physical interfaces. This example shows MSTP configured on logical interfaces.

    Table 1: Topology for Configuring MSTP on the QFX Series

    Components

    Settings

    Switch 1

    The following ports on Switch 1 are connected in this way:

    • xe-0/0/9 is connected to Switch 2
    • xe-0/0/13 is connected to Switch 4
    • xe-0/0/11 is connected to Switch 3

    Switch 2

    The following ports on Switch 2 are connected in this way:

    • xe-0/0/14 is connected to Switch 1
    • xe-0/0/18 is connected to Switch 3

    Switch 3

    The following ports on Switch 3 are connected in this way:

    • xe-0/0/26 is connected to Switch 1
    • xe-0/0/28 is connected to Switch 2
    • xe-0/0/24 is connected to Switch 4

    Switch 4

    The following ports on Switch 4 are connected in this way:

    • xe-0/0/19 is connected to Switch 1
    • xe-0/0/23 is connected to Switch 3

    VLAN names and tag IDs

    sales-vlan, tag 10
    engineering-vlan, tag 20
    publications-vlan, tag 30
    support-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 sales-vlan supports sales traffic and has a VLAN tag identifier of 10.
    • The engineering-vlan supports data traffic and has a VLAN tag identifier of 20.
    • The publications-vlan supports publications VLAN traffic (for supplicants that fail 802.1X authentication) and has a VLAN tag identifier of 30.
    • The support-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

    CLI Quick Configuration

    To quickly configure interfaces and MSTP on Switch 1, copy the following commands and paste them into the switch terminal window:

    Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

    [edit]

    set vlans sales-vlan description “Sales VLAN”

    set vlans sales-vlan vlan-id 10

    set vlans engineering-vlan description “Engineering VLAN”

    set vlans engineering-vlan vlan-id 20

    set vlans publications-vlan description “Publications VLAN”

    set vlans publications-vlan vlan-id 30

    set vlans support-vlan description “Support VLAN”

    set vlans support-vlan vlan-id 40

    set interfaces xe-0/0/13 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/9 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/11 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/13 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-0/0/9 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-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 xe-0/0/13.0 cost 1000

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

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

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

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

    set protocols mstp interface xe-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 xe-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:

    1. Configure the VLANs sales-vlan, engineering-vlan, publications-vlan, and support-vlan:
      [edit vlans]
      user@switch1# set sales-vlan description “Sales VLAN”
      user@switch1# set sales-vlan vlan-id 10
      user@switch1# set engineering-vlan description “Engineering VLAN”
      user@switch1# set engineering-vlan vlan-id 20
      user@switch1# set publications-vlan description “Publications VLAN”
      user@switch1# set publications-vlan vlan-id 30
      user@switch1# set support-vlan description “Support VLAN”
      user@switch1# set publications-vlan vlan-id 40
    2. Configure the VLANs on the interfaces, including support for the Ethernet switching protocol:
      [edit interfaces]
      user@switch1# set xe-0/0/13 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch1# set xe-0/0/9 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch1# set xe-0/0/11 unit 0 family ethernet-switching vlan members [10 20 30 40]
    3. Configure the port mode for the interfaces:

      Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

      [edit interfaces]
      user@switch1# set xe-0/0/13 unit 0 family ethernet-switching port-mode trunk
      user@switch1# set xe-0/0/9 unit 0 family ethernet-switching port-mode trunk
      user@switch1# set xe-0/0/11 unit 0 family ethernet-switching port-mode trunk
    4. 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 xe-0/0/13.0 cost 1000
      user@switch1# mstp interface xe-0/0/13.0 mode point-to-point
      user@switch1# mstp interface xe-0/0/9.0 cost 1000
      user@switch1# mstp interface xe-0/0/9.0 mode point-to-point
      user@switch1# mstp interface xe-0/0/11.0 cost 4000
      user@switch1# mstp interface xe-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 xe-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 {xe-0/0/13 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-0/0/9 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-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 xe-0/0/13.0 {cost 1000;mode point-to-point;}interface xe-0/0/9.0 {cost 1000;mode point-to-point;}interface xe-0/0/11.0 {cost 4000;mode point-to-point;}msti 1 {bridge-priority 16k;vlan [ 10 20 ];interface xe-0/0/11.0 {cost 4000;}}msti 2 {bridge-priority 8k;vlan [ 30 40 ];}}
    vlans {sales-vlan {vlan-id 10;}engineering-vlan {vlan-id 20;}publications-vlan {vlan-id 30;}support-vlan {vlan-id 40;}}

    Configuring MSTP on Switch 2

    CLI Quick Configuration

    To quickly configure interfaces and MSTP on Switch 2, copy the following commands and paste them into the switch terminal window:

    Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

    [edit]

    set vlans sales-vlan description “Sales VLAN”

    set vlans sales-vlan vlan-id 10

    set vlans engineering-vlan description “Engineering VLAN”

    set vlans engineering-vlan vlan-id 20

    set vlans publications-vlan description “Publications VLAN”

    set vlans publications-vlan vlan-id 30

    set vlans support-vlan description “Support VLAN”

    set vlans support-vlan vlan-id 40

    set interfaces xe-0/0/14 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/18 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/14 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-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 xe-0/0/14.0 cost 1000

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

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

    set protocols mstp interface xe-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:

    1. Configure the VLANs sales-vlan, engineering-vlan, publications-vlan, and support-vlan:
      [edit vlans]
      user@switch2# set sales-vlan description “Sales VLAN”
      user@switch2# set sales-vlan vlan-id 10
      user@switch2# set engineering-vlan description “Engineering VLAN”
      user@switch2# set engineering-vlan vlan-id 20
      user@switch2# set publications-vlan description “Publications VLAN”
      user@switch2# set publications-vlan vlan-id 30
      user@switch2# set support-vlan vlan-description “Support VLAN”
      user@switch2# set publications-vlan vlan-id 40
    2. Configure the VLANs on the interfaces, including support for the Ethernet switching protocol:
      [edit interfaces]
      user@switch2# set xe-0/0/14 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch2# set xe-0/0/18 unit 0 family ethernet-switching vlan members [10 20 30 40]
    3. Configure the port mode for the interfaces:

      Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

      [edit interfaces]
      user@switch2# set xe-0/0/14 unit 0 family ethernet-switching port-mode trunk
      user@switch2# set xe-0/0/18 unit 0 family ethernet-switching port-mode trunk

    4. 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 xe-0/0/14.0 cost 1000
      user@switch2# mstp interface xe-0/0/14.0 mode point-to-point
      user@switch2# mstp interface xe-0/0/18.0 cost 1000
      user@switch2# mstp interface xe-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 {xe-0/0/14 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-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 xe-0/0/14.0 {cost 1000;mode point-to-point;}interface xe-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 {sales-vlan {vlan-id 10;}engineering-vlan {vlan-id 20;}publications-vlan {vlan-id 30;}support-vlan {vlan-id 40;}}

    Configuring MSTP on Switch 3

    CLI Quick Configuration

    To quickly configure interfaces and MSTP on Switch 3, copy the following commands and paste them into the switch terminal window:

    Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

    [edit]

    set vlans sales-vlan description “Sales VLAN”

    set vlans sales-vlan vlan-id 10

    set vlans engineering-vlan description “Engineering VLAN”

    set vlans engineering-vlan vlan-id 20

    set vlans publications-vlan description “Publications VLAN”

    set vlans publications-vlan vlan-id 30

    set vlans support-vlan description “Support VLAN”

    set vlans support-vlan vlan-id 40

    set interfaces xe-0/0/26 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/28 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/24 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/26 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-0/0/28 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-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 xe-0/0/26.0 cost 1000

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

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

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

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

    set protocols mstp interface xe-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:

    1. Configure the VLANs sales-vlan, engineering-vlan, publications-vlan, and support-vlan:
      [edit vlans]
      user@switch3# set sales-vlan description “Sales VLAN”
      user@switch3# set sales-vlan vlan-id 10
      user@switch3# set engineering-vlan description “Engineering VLAN”
      user@switch3# set engineering-vlan vlan-id 20
      user@switch3# set publications-vlan description “Publications VLAN”
      user@switch3# set publications-vlan vlan-id 30
      user@switch3# set support-vlan description “Support VLAN”
      user@switch3# set publications-vlan vlan-id 40
    2. Configure the VLANs on the interfaces, including support for the Ethernet switching protocol:
      [edit interfaces]
      user@switch3# set xe-0/0/26 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch3# set xe-0/0/28 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch3# set xe-0/0/24 unit 0 family ethernet-switching vlan members [10 20 30 40]
    3. Configure the port mode for the interfaces:

      Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

      [edit interfaces]
      user@switch3# set xe-0/0/26 unit 0 family ethernet-switching port-mode trunk
      user@switch3# set xe-0/0/28 unit 0 family ethernet-switching port-mode trunk
      user@switch3# set xe-0/0/24 unit 0 family ethernet-switching port-mode trunk
    4. 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 xe-0/0/26.0 cost 1000
      user@switch3# mstp interface xe-0/0/26.0 mode point-to-point
      user@switch3# mstp interface xe-0/0/28.0 cost 1000
      user@switch3# mstp interface xe-0/0/28.0 mode point-to-point
      user@switch3# mstp interface xe-0/0/24.0 cost 1000
      user@switch3# mstp interface xe-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 {xe-0/0/26 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-0/0/28 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-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 xe-0/0/26.0 {cost 1000;mode point-to-point;}interface xe-0/0/28.0 {cost 1000;mode point-to-point;}interface xe-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 {sales-vlan {vlan-id 10;}engineering-vlan {vlan-id 20;}publications-vlan {vlan-id 30;}support-vlan {vlan-id 40;}}

    Configuring MSTP on Switch 4

    CLI Quick Configuration

    To quickly configure interfaces and MSTP on Switch 4, copy the following commands and paste them into the switch terminal window:

    Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

    [edit]

    set vlans sales-vlan description “Sales VLAN”

    set vlans sales-vlan vlan-id 10

    set vlans engineering-vlan description “Engineering VLAN”

    set vlans engineering-vlan vlan-id 20

    set vlans publications-vlan description “Publications VLAN”

    set vlans publications-vlan vlan-id 30

    set vlans support-vlan description “Support VLAN”

    set vlans support-vlan vlan-id 40

    set interfaces xe-0/0/23 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/19 unit 0 family ethernet-switching vlan members [10 20 30 40]

    set interfaces xe-0/0/23 unit 0 family ethernet-switching port-mode trunk

    set interfaces xe-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 xe-0/0/23.0 cost 1000

    set protocols mstp interface xe-0/0/23.0 mode point-to-point

    set protocols mstp interface xe-0/0/19.0 cost 1000

    set protocols mstp interface xe-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:

    1. Configure the VLANs sales-vlan, engineering-vlan, publications-vlan, and support-vlan:
      [edit vlans]
      user@switch4# set sales-vlan description “Sales VLAN”
      user@switch4# set sales-vlan vlan-id 10
      user@switch4# set engineering-vlan description “Engineering VLAN”
      user@switch4# set engineering-vlan vlan-id 20
      user@switch4# set publications-vlan description “Publications VLAN”
      user@switch4# set publications-vlan vlan-id 30
      user@switch4# set support-vlan description “Support VLAN”
      user@switch4# set publications-vlan vlan-id 40
    2. Configure the VLANs on the interfaces, including support for the Ethernet switching protocol:
      [edit interfaces]
      user@switch4# set xe-0/0/23 unit 0 family ethernet-switching vlan members [10 20 30 40]
      user@switch4# set xe-0/0/19 unit 0 family ethernet-switching vlan members [10 20 30 40]
    3. Configure the port mode for the interfaces:

      Note: If you are configuring MSTP on devices that support the Enhanced Layer 2 Switching (ELS) CLI, use the interface-mode statement instead of the port-mode statement. The port-mode statement has been replaced with the interface-mode statement.

      [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
    4. 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 xe-0/0/23.0 cost 1000
      user@switch4# mstp interface xe-0/0/23.0 mode point-to-point
      user@switch4# mstp interface xe-0/0/19.0 cost 1000
      user@switch4# mstp interface xe-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 {xe-0/0/23 {unit 0 {family ethernet-switching {port-mode trunk;vlan {members 10;members 20;members 30;members 40;}}}}xe-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 xe-0/0/23.0 {cost 1000;mode point-to-point;}interface xe-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 {sales-vlan {vlan-id 10;}engineering-vlan {vlan-id 20;}publications-vlan {vlan-id 30;}support-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:

    Spanning tree interface parameters for instance 0
    
    Interface    Port ID    Designated      Designated         Port    State  Role
                             port ID        bridge ID          Cost
    xe-0/0/13.0    128:527      128:525  16384.0019e25040e0      1000  FWD    ROOT 
    xe-0/0/9.0     128:529      128:513  32768.0019e2503d20      1000  BLK    ALT  
    xe-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
    xe-0/0/13.0    128:527      128:525  16385.0019e25040e0      1000  FWD    ROOT 
    xe-0/0/9.0     128:529      128:513  32769.0019e2503d20      1000  BLK    ALT  
    xe-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
    xe-0/0/13.0    128:527      128:527   8194.0019e25044e0      1000  FWD    DESG 
    xe-0/0/9.0     128:529      128:513   4098.0019e2503d20      1000  FWD    ROOT 
    xe-0/0/11.0    128:531      128:531   8194.0019e25044e0      1000  FWD    DESG 
    
    
    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                         : xe-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                         : xe-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                         : xe-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 the 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:

    
    Spanning tree interface parameters for instance 0
    
    Interface    Port ID    Designated      Designated         Port    State  Role
                             port ID        bridge ID          Cost
    xe-0/0/14.0     128:513      128:513  32768.0019e2503d20      1000  FWD    DESG 
    xe-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
    xe-0/0/14.0     128:513      128:513  32769.0019e2503d20      1000  FWD    DESG 
    xe-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
    xe-0/0/14.0     128:513      128:513   4098.0019e2503d20      1000  FWD    DESG   
    xe-0/0/18.0     128:519      128:519   4098.0019e2503d20      1000  FWD    DESG
    
    
    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                         : xe-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                         : xe-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.

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

    Verifying MSTP Configuration on Switch 3

    Purpose

    Verify the MSTP configuration on Switch 3.

    Action

    Use the operational mode commands:

    Spanning tree interface parameters for instance 0
    
    Interface    Port ID    Designated      Designated         Port    State  Role
                             port ID        bridge ID          Cost
    xe-0/0/26.0     128:513      128:513   8192.0019e25051e0      1000  FWD    DESG 
    xe-0/0/28.0     128:515      128:515   8192.0019e25051e0      1000  FWD    DESG 
    xe-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
    xe-0/0/26.0     128:513      128:513   4097.0019e25051e0      1000  FWD    DESG 
    xe-0/0/28.0     128:515      128:515   4097.0019e25051e0      1000  FWD    DESG 
    xe-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
    xe-0/0/26.0     128:513      128:531   8194.0019e25044e0      1000  BLK    ALT  
    xe-0/0/28.0     128:515      128:519   4098.0019e2503d20      1000  FWD    ROOT 
    xe-0/0/24.0     128:517      128:517  16386.0019e25051e0      1000  FWD    DESG
     
    
    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                         : xe-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.

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

    Verifying MSTP Configuration on Switch 4

    Purpose

    Verify the MSTP configuration on Switch 4.

    Action

    Use the operational mode commands:

    Spanning tree interface parameters for instance 0
    
    Interface    Port ID    Designated      Designated         Port    State  Role
                             port ID        bridge ID          Cost
    
    xe-0/0/23.0    128:523      128:517   8192.0019e25051e0      1000  FWD    ROOT 
    xe-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 
    xe-0/0/23.0    128:523      128:517   4097.0019e25051e0      1000  FWD    ROOT 
    xe-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
    xe-0/0/23.0    128:523      128:517  16386.0019e25051e0      1000  BLK    ALT  
    xe-0/0/19.0    128:525      128:527   8194.0019e25044e0      1000  FWD    ROOT 
    
    
    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                         : xe-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                         : xe-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                         : xe-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.

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

    Modified: 2016-08-30