C H A P T E R 4

STP

##

4.1 STP

STP is a link management protocol that provides path redundancy while preventing undesirable loops in the network that are created by multiple active paths between devices. To establish path redundancy, STP creates a tree that spans all of the switches in an extended network, forcing redundant paths into a standby or blocked state.

For an Ethernet network to function properly, only one active path must exist between two stations. Multiple active paths between stations in a bridged network can cause loops in which Ethernet frames can endlessly circulate. STP can logically break such loops and prevent looping traffic from clogging the network. The dynamic control of the topology provides continued network operation in the presence of redundant or unintended looping paths.

##

4.2 STP Commands

The following commands enable you to configure STP:

- spanning-tree mode mst|rst

- spanning-tree

- spanning-tree compatibility

- spanning-tree timers

- spanning-tree mst forward-time / spanning-tree mst max-age

- spanning-tree transmit hold-count

- spanning-tree mst max-hops

- spanning-tree priority / spanning-tree mst root

- spanning-tree mst configuration

- name

- revision

- instance

- spanning-tree auto-edge

- spanning-tree

- spanning-tree restricted-role

- spanning-tree restricted-tcn

- spanning-tree mst - Properties of an interface for MSTP

- spanning-tree mst hello-time

- clear spanning-tree counters

- spanning-tree pathcost dynamic [lag-speed]

- clear spanning-tree detected protocols

- shutdown spanning-tree

- debug spanning-tree

- show spanning-tree

- show spanning-tree redundancy

- show spanning-tree detail

- show spanning-tree active

- show spanning-tree interface

- show spanning-tree root

- show spanning-tree bridge

- show spanning-tree mst - CIST or Specified MST Instance

- show spanning-tree mst configuration

- show spanning-tree mst - Port Specific Information

- show customer spanning-tree

- spanning-tree mode-mst|rst|pvrst|pvst

- spanning-tree vlan

- spanning-tree bpduguard

- spanning-tree guard

- spanning-tree encap

- spanning-tree vlan status

- spanning-tree vlan port-priority

- spanning-tree vlan cost

- show spanning-tree vlan - blockedports|pathcost|summary

- show spanning-tree vlan - bridge

- show spanning-tree vlan - root

- show spanning-tree vlan - interface

- show spanning-tree interface

- spanning-tree layer2-gateway-port

- spanning-tree bpdu-receive

- spanning-tree bpdu-transmit / spanning-tree bpdufilter

- spanning-tree mst - pseudoRootID priority

- show spanning-tree interface layer2-gateway-port

- spanning-tree mst max-instance

##

4.3 PVRST+

PVRST+ is a link management protocol that provides path redundancy while preventing undesirable loops in the network that are created by multiple active paths between stations working on same VLAN. To establish path redundancy, STP creates a tree for each VLAN that spans on the switches working on that VLAN, forcing redundant paths into a standby, or blocked state.

For an Ethernet network to function properly, only one active path must exist between two stations. Multiple active paths between stations in a bridged network can cause loops in which Ethernet frames can endlessly circulate. STP can logically break such loops and prevent looping traffic from clogging the network. The dynamic control of the topology provides continued network operation in the presence of redundant or unintended looping paths.

Note - For each VLAN, a spanning-tree instance is created. The number of spanning-tree instances supported in PVRST+ will depend on the number of instances supported by the hardware. There can be more VLANs operating in the switch, but PVRST+ will be operating only on supported instances.

##

4.4 PVRST+ Commands

The list of commands used for PVRST+ is as follows:

- spanning-tree mode-mst|rst|pvrst|pvst

- spanning-tree vlan

- spanning-tree bpduguard

- spanning-tree guard

- spanning-tree encap

- spanning-tree vlan status

- spanning-tree vlan port-priority

- spanning-tree vlan cost

- show spanning-tree vlan - blockedports|pathcost|summary

- show spanning-tree vlan - bridge

- show spanning-tree vlan - root

- show spanning-tree vlan - interface

- show spanning-tree interface

##

4.5 STP and PVRST+ Commands

### 4.5.1 `spanning-tree mode mst|rst`

Sets the spanning-tree operating mode.

    spanning-tree mode {mst | rst}

Syntax Description | mst - MSTP configuration rst - RSTP configuration
Mode | Global Configuration
Defaults | mst
Example | `SEFOS(config)#` spanning-tree mode rst
Notes | When SEFOS boots up, spanning-tree is enabled by default with MSTP operating in the switch. This command only starts and enables the spanning-tree mode. However, port-roles and states are computed only after enabling the spanning-tree. If the user-input for the spanning-tree mode is different from the current mode of operation, then SEFOS shuts down the operational spanning-tree and starts the spanning-tree per user-input.

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.2 `spanning-tree`

Enables the spanning-tree operation. The `no` form of the command disables the spanning-tree operation.

    spanning-tree

    no spanning-tree

Mode | Global Configuration
Defaults | Spanning-tree enabled is MSTP
Example | `SEFOS(config)#` spanning-tree

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.3 `spanning-tree compatibility`

Sets the compatibility version for the spanning-tree protocol. The `no` form of the command sets the compatibility version for spanning-tree protocol to its default value.

    spanning-tree compatibility {stp | rst | mst}

    no spanning-tree compatibility

Syntax Description | stp - STP configuration rst - RSTP configuration mst - MSTP configuration
Mode | Global Configuration
Defaults | If spanning-tree protocol enabled is MST, then MSTP compatible. If spanning-tree protocol enabled is RST, then RSTP compatible.
Example | `SEFOS(config)#` spanning-tree compatibility stp
Notes | The option mst is available only when MSTP is the operational mode of the spanning-tree. When the spanning-tree mode is `mst`, the fields in the dot1d Bridge-MIB are not updated, even when the compatibility mode has been set to `rst` or `stp`. If you want to use these MIB variables to manage or observe the switch, you must use spanning-tree mode `rst`.

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.4 `spanning-tree timers`

Sets the spanning-tree timers in seconds. The `no` form of the command sets the spanning-tree timers to the default values.

    spanning-tree {forward-time 4-30 | hello-time 1-2 | max-age 6-40}

    no spanning-tree { forward-time | hello-time | max-age }

Syntax Description | forward-time - Controls how fast a port changes its spanning-tree state from blocking state to forwarding state (in seconds). hello-time- Determines how often the switch broadcasts its hello message to other switches when it is the root of the spanning-tree (in seconds). max-age - The maximum age allowed for the STP information learnt from the network on any port before it is discarded (in seconds).
Mode | Global Configuration
Defaults | forward-time - 15 hello-time- 2 max-age - 20
Example | `SEFOS(config)#` spanning-tree max-age 6 SEFOS(config)# spanning-tree hello-time 1 SEFOS(config)# spanning-tree forward-time 4
Notes | The following relation must be observed while configuring the timers: 2 * (Forward-time - 1) >= Max-age Max-Age >= 2 * (Hello-time +1)

#### Related Commands

- show spanning-tree bridge - Displays spanning-tree configuration of the bridge forward time

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.5 `spanning-tree mst forward-time`

Configures the forward timer of the spanning-tree. The `no` form of the command sets the forward timer to the default value. The forward timer controls the speed at which a port changes its spanning-tree state from blocking state to forwarding state. The timer value ranges between 4 and 30 seconds.

This command operates similar to that of the command spanning-tree timers, but configures only the forward timer.

    spanning-tree mst forward-time 4-30

    no spanning-tree mst forward-time

Mode | Global Configuration
Defaults | forward-time - 15
Example | `SEFOS(config)#` spanning-tree mst forward-time 4
Notes | The following relation must be observed while configuring the timers: 2 * (Forward-time - 1) >= Max-age

#### Related Commands

- show spanning-tree bridge - Displays spanning-tree configuration of the bridge forward time

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.6 `spanning-tree mst max-age`

Configures the max-age timer of the spanning-tree. The `no` form of the command sets the `max-age` timer to the default value. The `max-age` timer denotes the time (in seconds) after which the spanning-tree protocol information learnt from the network on any port will be discarded. The timer value ranges between 6 and 40 seconds.

This command operates similar to the command spanning-tree timers, but configures only the `max-age` timer.

    spanning-tree mst max-age 6-40

    no spanning-tree mst max-age

Mode | Global Configuration
Defaults | max-age - 20
Example | `SEFOS(config)#` spanning-tree mst max-age 7
Notes | The following relation must be observed while configuring the timers: 2 * (Forward-time - 1) >= Max-age Max-Age >= 2 * (Hello-time +1)

#### Related Commands

- show spanning-tree bridge - Displays spanning-tree configuration of the bridge forward time

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.7 `spanning-tree transmit hold-count`

Sets the transmit hold-count value. The `no` form of the command sets the transmit `hold-count` to default value. The transmit `hold-count` value is a counter used to limit the maximum transmission rate of the switch.

    spanning-tree transmit hold-count 1-10

    no spanning-tree transmit hold-count

Mode | Global Configuration
Defaults | 3
Example | `SEFOS(config)#` spanning-tree transmit hold-count 5

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.8 `spanning-tree mst max-hops`

Sets the maximum number of hops permitted in the MST. The `no` form of the command sets the maximum number of hops permitted in the MST to the default value.

    spanning-tree mst max-hops 6-40

    no spanning-tree mst max-hops

Mode | Global Configuration
Defaults | 20
Example | `SEFOS(config)#` spanning-tree mst max-hops 10
Notes | The root switch of the instance always sends a BPDU with a cost of 0 and the hop count set to the maximum value.

#### Related Commands

show spanning-tree mst configuration - Displays multiple spanning-tree instance configuration

### 4.5.9 `spanning-tree priority`

Sets the bridge priority for the spanning-tree only in steps of 4096. The `no` form of the command sets the bridge priority to the default value.

    spanning-tree [mst instance-id_1-64] [priority 0-61440]

    no spanning-tree [mst instance-id_1-64] priority

Mode | Global Configuration
Defaults | 32768
Example | `SEFOS(config)#` spanning-tree priority 4096
Notes | spanning-tree priority`` 0-61440 configures the priority in RSTP if RSTP is running, or configures the CIST priority if MSTP is running. spanning-tree mst`` instance-id_1-64`` priority`` 0-61440 configures the priority in MSTI and is supported only if MSTP is running.

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.10 `spanning-tree mst root`

    spanning-tree mst instance-id_1-64 root {primary | secondary}

    no spanning-tree mst instance-id_1-64 root

Syntax Description | instance-id_1-64 - Instance identification number. This value ranges between 1 and 64. primary - Sets high enough priority (low value) for the switch so that the switch can be made as the bridge root of the spanning-tree instance. The priority value will be set as 24576. secondary - Sets the switch as a secondary root if the primary root fails. The priority value will be set as 28672.
Mode | Global Configuration
Example | `SEFOS(config)#` spanning-tree mst instance-id 1 root secondary

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.11 `spanning-tree mst configuration`

Helps enter MST configuration submode.

    spanning-tree mst configuration

Mode | Global Configuration
Example | `SEFOS(config)#` spanning-tree mst configuration
Notes | In MST mode, the switch supports up to 64 instances. This MST configuration submode is used to make instance-specific and MST region configurations only. The switch supports up to 64 instances.

#### Related Commands

show spanning-tree mst configuration - Displays multiple spanning-tree instance configurations

### 4.5.12 `name`

Sets the configuration name for the MST region. The `no` form of the command deletes the configuration name.

    name optional-max-length-string

    no name

Mode | MSTP Configuration
Defaults | The default configuration name is 00: 00: 00: 00: 00: 00
Example | `SEFOS`(config-mst)# name regionone
Notes | The name string is case sensitive.

#### Related Commands

show spanning-tree mst configuration - Displays multiple spanning-tree instance configuration

### 4.5.13 `revision`

Sets the configuration revision number for the MST region. The `no` form of the command deletes the configuration revision number.

    revision 0-65535

    no revision

Mode | MSTP Configuration
Defaults | 0
Example | `SEFOS(config`-mst)# revision 100

#### Related Commands

show spanning-tree mst configuration - Displays multiple spanning-tree instance configurations

### 4.5.14 `instance`

Maps VLANs to an MST instance. The `no` form of the command deletes the instance and unmaps specific VLANs from the MST instance.

    instance {instance-id_1-64 | 4094} [vlan vlan-range]

    no instance instance-id_1-64 [vlan vlan-range]

Syntax Description | vlan - The VLAN range associated with a spanning-tree instance. MST instance 4094 is used only in Provider backbone bridging (BPP-TE) and is not supported in this release.
Mode | MSTP Configuration
Defaults | VLANs mapped for instance 0: 11-1024, 1025-2048, 2049-3072,3073-4094.
Example | `SEFOS(config`-mst`)#` instance 2 vlan 2
Notes | A single VLAN identified by a VLAN ID number is specified by a range of VLANs separated by a hyphen, or a series of VLANs separated by a comma.

#### Related Commands

show spanning-tree mst configuration - Displays multiple spanning-tree instance configuration

### 4.5.15 `spanning-tree auto-edge`

Enables automatic detection of a bridge attached to an interface. The `no` form of the command disables automatic detection of a bridge attached to an interface.

    spanning-tree auto-edge

    no spanning-tree auto-edge

Mode | Interface Configuration
Example | `SEFOS(config-if)#` spanning-tree auto-edge

#### Related Commands

show spanning-tree bridge - Displays the spanning-tree configuration of the bridge

### 4.5.16 `spanning-tree`

Sets the spanning-tree properties of an interface. The `no` form of the command sets the spanning-tree properties of an interface to the default value.

    spanning-tree {cost 0-200000000 | disable | link-type {point-to-point | shared} | portfast | port-priority 0-240}

    no spanning-tree {cost | disable | link-type | portfast | port-priority}

Syntax Description | cost - Path cost value associated with the port. disable - Disables the spanning-tree on the port. link-type - The link can be a point-to-point link or can be a shared LAN segment on which another bridge is present. The `no` form of the command sets the link type as auto. portfast - Specifies that port has only hosts connected and hence can transition to forwarding rapidly. port-priority - Port priority value.
Mode | Interface Configuration
Defaults | cost - 200000 port-priority - 128.1 portfast - Not in `portfast.` link-type - Shared.
Example | `SEFOS(config`-if`)#` spanning-tree cost 2200 SEFOS(config-if)# spanning-tree link-type point-to-point SEFOS(config-if)# spanning-tree portfast SEFOS(config-if)# spanning-tree port-priority 25
Notes | In MSTP mode, this configuration applies to the CIST context.

#### Related Commands

show spanning-tree interface - Displays the spanning-tree port specific configuration.

### 4.5.17 `spanning-tree restricted-role`

Enables the root-guard or restricted role feature on the port (prevents a specific port from becoming the root port). The `no` form of the command disables the root-guard or restricted role feature on the port.

    spanning-tree restricted-role

    no spanning-tree restricted-role

Mode | Interface Configuration
Defaults | Disabled.
Example | `SEFOS(config-if)#` spanning-tree restricted-role

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

### 4.5.18 `spanning-tree restricted-tcn`

Enables the topology change guard or restricted TCN feature on the port (prevents the topology change caused by that port). The `no` form of the command disables the topology change guard or restricted TCN feature on the port.

    spanning-tree restricted-tcn

    no spanning-tree restricted-tcn

Mode | Interface Configuration
Defaults | Disabled
Example | `SEFOS(config-if)#` spanning-tree restricted-tcn

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

### 4.5.19 `spanning-tree mst -` Properties of an interface for MSTP

Sets the spanning-tree properties of an interface for MSTP. The `no` form of the command sets the spanning-tree properties of an interface to the default value. The port-priority must be in increments of 16 with a maximum value of 240.

    spanning-tree mst instance-id_1-64 {cost 1-200000000 | port-priority 0-240 | disable}

    no spanning-tree mst instance-id_1-64 {cost | port-priority | disable}

Syntax Description | cost - Cost value associated with the port port-priority - Port priority value disable - Disables the spanning-tree on the port
Mode | Interface Configuration
Defaults | cost - 200000 port-priority - 128
Example | `SEFOS(config-if)#` spanning-tree mst 2 cost 4000 SEFOS(config-if)# spanning-tree mst 1 port-priority 32 SEFOS(config-if)# spanning-tree mst 2 disable
Notes | The MST instance must exist for this command. If all interfaces have the same priority value, the MST instance places the interface with the lowest interface number in the forwarding state and blocks other interfaces.

#### Related Commands

show spanning-tree mst - CIST or Specified MST Instance - Displays the spanning-tree properties of an interface for an MSTP instance

### 4.5.20 `spanning-tree mst hello-time`

This command configures the spanning tree hello time.

The `no` form of this command resets the hello time to its default value.

The hello time represents the time interval (in seconds) between two successive

configuration BPDUs generated by the switch on the port. This value is either 1 or 2 seconds. This value is applied to all active MSTIs.

    spanning-tree mst hello-time seconds_1-2

    no spanning-tree mst hello-time

Mode | Global Configuration, Interface Configuration
Defaults | 2 seconds.
Example | SEFOS(config-if)# spanning-tree mst hello-time 1 SEFOS(config)# spanning-tree mst hello-time 1
Notes | This command can be executed successfully, only if the spanning tree functionality is not shutdown in the switch. The type of spanning tree mode should be set as mst.

#### Related Commands

- shutdown spanning-tree - Shuts down spanning tree functionality in the switch.

- `spanning-tree mode` - Sets the type of spanning tree to be executed, enables spanning tree operation and starts spanning tree functionality in the switch.

- `show spanning-tree` - Summary, Blockedports, Pathcost, redundancy - Displays spanning tree related information available in the switch for the current STP enabled in the switch.

- show spanning-tree detail - Displays detailed spanning tree related information of the switch and all ports enabled in the switch.

- show spanning-tree interface - Displays the port related spanning tree information for the specified interface.

- show spanning-tree root - Displays the spanning tree root information.

- show spanning-tree bridge - Displays the spanning tree bridge information.

- `show spanning-tree mst` - Port Specific Configuration - Displays multiple spanning tree port speci fic information for the specified port.

### 4.5.21 `clear spanning-tree counters`

Resets all bridge and port level spanning tree statistics counters.

For RSTP, the information contains the number of:

- Transitions to forwarding state

- RSTP BPDU count received / transmitted

- Config BPDU count received / transmitted

- TCN BPDU count received / transmitted

- Invalid BPDU count transmitted

- Port protocol migration count

For MSTP, the information contains the number of:

- Port forward transitions

- Port received BPDUs

- Port transmitted BPDUs

- Port invalid BPDUs received

- Port protocol migration count

- BPDUs sent / received for each MSTI

For PVRST, the information contains the number of:

- Transitions to forwarding state

- PVRST BPDU count received / transmitted

- Config BPDU count received / transmitted

- TCN BPDU count received / transmitted

- Port protocol migration count

    clear spanning-tree [mst instance-id] counters [interface interface-type interface-id]

Syntax Description | mst instance-id - Clears the statistical counters specific to the MSTP instance already created in the switch. This value ranges between 1 and 64. The special value 4094 can be used only in the switch that supports Provider backbone bridging (BPP-TE) and is not supported in this release. This option is applicable, only if the spanning tree mode is set as `mst`. interface interface-type interface-id - Clears all port-level spanning-tree statistics counters for the given port.
Mode | Global Configuration
Example | `SEFOS(config)#` clear spanning-tree mst 1 counters
Notes | The statistics information can be deleted only if the spanning tree functionality is not shutdown in the switch. The type of spanning tree mode should be set if the functionality is already shutdown. Valid interfaces include physical ports, VLANs, and port channels. Port protocol migration count gets incremented consistently when there is a protocol migration.

#### Related Commands

- shutdown spanning-tree - Shuts down spanning tree functionality in the switch.

- spanning-tree mode mst|rst - Sets the type of spanning tree to be executed, enables spanning tree operation and starts spanning tree functionality in the switch.

- instance - Creates an MST instance and maps it to VLANs.

- show spanning-tree detail - Displays detailed spanning tree related information of the switch and all ports enabled in the switch.

- show spanning-tree active - Displays detailed spanning tree related information of the switch and all ports enabled in the switch.

- show spanning-tree interface - Displays the port related spanning tree information for the specified interface.

- show spanning-tree mst - CIST or Specified MST Instance - CIST or specified mst Instance - Displays multiple spanning tree information for all MSTIs in the switch.

- show spanning-tree mst - Port Specific Information - Displays multiple spanning tree port specific information for the specified port.

- spanning-tree vlan - Summary, Blockedports, Pathcost - Displays PVRST related information for the speci fied VLAN.

- show spanning-tree vlan - interface - Displays interface specific PVRST information for the specified VLAN.

### 4.5.22 `spanning-tree pathcost dynamic [lag-speed]`

Enables dynamic path cost calculation feature in the switch. The `no` form of the command disables dynamic path cost calculation. The dynamic pathcost calculation feature is disabled, even if the spanning tree mode is changed.

    spanning-tree pathcost dynamic [lag-speed]

    no spanning-tree pathcost dynamic [lag-speed]

Syntax Description | lag-speed - Calculates the path cost for change in speed of the port. This feature is used for LA ports whose speed changes due to addition or deletion of ports from the port channel. The manually assigned path cost is used even if the lag speed feature is enabled in the switch, if the path cost is assigned manually. The lag speed feature can be enabled only after enabling the dynamic pathcost calculation feature.
Mode | Global Configuration
Defaults | Disabled
Example | `SEFOS(config)#` spanning-tree pathcost dynamic
Notes | The dynamic pathcost calculation feature can be configured in the switch, only if the spanning tree functionality is not shutdown in the switch. The type of spanning tree mode should be set, if the functionality is already shutdown. This feature is applied only for the ports that are not shutdown during the execution of STP. On execution of this command, the path cost of all the ports are calculated dynamically based on the speed of the interface. This feature is applied only for the ports that are not shutdown during the execution of STP. If the cost has already been configured for a CIST or an RSTP interface, this command has no effect on those interfaces. If the cost has been configured previously for an MST instance on a particular interface, this command has no effect on that instance in the specified interface. Whereas, the path cost of all the other instances on the same interface are calculated dynamically.

#### Related Commands

- spanning-tree compatibility - Sets the compatibility version for the spanning-tree protocol

- `spanning-tree -` Properties of an interface - Sets the spanning-tree properties of an interface

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

### 4.5.23 `spanning-tree loop-guard`

Enables the loop guard feature in a port. This feature prevents the alternative or root ports from becoming designated ports due to failure in a unidirectional link. This feature is useful when the neighbor bridge is faulty, that is, the bridge cannot send BPDUs but continues to send data traffic.

The `no` form of this command disables the loop guard feature in the port. The loop guard feature is disabled, even if the spanning tree mode is changed.

    spanning-tree loop-guard

    no spanning-tree loop-guard

Mode | Interface Configuration
Default | Disabled in all ports.
Example | SEFOS(config-if)# spanning-tree loop-guard
Notes | The loop guard feature can be configured, only if the spanning tree functionality is not shutdown in the switch. The type of spanning tree mode should be set, if the functionality is already shutdown.

#### Related Commands

- shutdown spanning-tree - Shuts down spanning tree functionality in the switch.

- `spanning-tree mode` - Sets the type of spanning tree to be executed, enables spanning tree operation and starts spanning tree functionality in the switch.

- show spanning-tree detail - Displays detailed spanning tree related information of the switch and all ports enabled in the switch.

- `show spanning-tree active detail` - Displays detailed spanning tree related information of the switch and all ports enabled in the switch.

- show spanning-tree interface - Displays the port related spanning tree information for the specified interface.

### 4.5.24 `clear spanning-tree detected protocols`

Restarts the protocol migration process on all the interfaces and forces renegotiation with the neighboring switches.

    clear spanning-tree detected protocols [{interface interface-type interface-id | switch context-name}]

Syntax Description | interface interface-type interface-id - Restarts the protocol migration process on the specified interface. Valid interfaces include physical ports, VLANs, and port channels. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | `SEFOS#` clear spanning-tree detected protocols interface extreme-ethernet 0/1
Notes | Port protocol migration count gets incremented consistently when there is a protocol migration.

#### Related Commands

- show spanning-tree interface - Displays the spanning-tree port specific configuration

- show spanning-tree mst - Port Specific Information - Displays multiple spanning-tree port specific configuration

### 4.5.25 `shutdown spanning-tree`

Shuts down spanning-tree operation.

    shutdown spanning-tree

Mode | Global Configuration
Defaults | MSTP is started and enabled.
Example | `SEFOS(config)#` shutdown spanning-tree
Notes | MSTP and RSTP are mutually exclusive and thus the MSTP module must be shutdown to start the RSTP module. The bridge module must be enabled for RSTP to be started.

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- show spanning-tree detail - Displays detailed spanning-tree information for STP/RSTP/MSTP configurations

### 4.5.26 `debug spanning-tree`

Provides spanning-tree debugging support. The `no` form of the command disables debugging.

    debug spanning-tree {global | {all | errors | init-shut | management | memory | bpdu | events | timer | state-machine {port-info | port-receive | port-role-selection | role-transition | state-transition | protocol-migration | topology-change | port-transmit | bridge-detection | pseudoInfo } | redundancy | sem-variables} switch context-name}

    no debug spanning-tree {global | {all | errors | init-shut | management | memory | bpdu |events | timer | state-machine {port-info | port-receive | port-role-selection | role-transition | state-transition | protocol-migration | topology-change | port-transmit | bridge-detection | pseudoInfo } redundancy | sem-variables} switch context-name}

Syntax Description | global - Global debug messages (this parameter is specific to multiple instance). all - All RSTP or MSTP debug messages. errors - Error code debug messages. init-shut - Init and Shutdown debug messages. management - Management messages. memory - Memory related messages. bpdu - BPDU related messages. timer - Timer module messages. events - Events related messages. state machine - State-machine related debug messages. port-info - Port information messages. port-recieve - Port received messages. port-role-selection - Port role selection messages. role-transition - Role transition messages. state-transition - State transition messages. protocol-migration - Protocol migration messages. topology-change - Topology change messages. port-transmit - Port transmission messages. bridge-detection - Bridge detection messages. pseudoInfo - Pseudo information debug statements. redundancy - Redundancy related messages. The keyword `redundancy` is not supported. sem-variables - State-machine variables debug messages. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Defaults | Debugging is disabled.
Example | `SEFOS#` debug spanning-tree all

#### Related Commands

show spanning-tree detail - Displays detailed spanning-tree information for STP/RSTP/MSTP configuration

### 4.5.27 `show spanning-tree`

Displays spanning-tree information, such as summary, blockedports, and path cost.

    show spanning-tree [{summary | blockedports | pathcost method}] [switch context-name]

Syntax Description | summary - Summary of port states. blockedports - Blocked ports in the system. pathcost method - Path cost method configured for a bridge. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Defaults | When SEFOS boots up, spanning-tree is enabled by default with MSTP operating in the switch.
Example | Single Instance: SEFOS# show spanning-tree Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 1900 Port 73 [po1] Max age 20 Sec, forward delay 15 Sec Hello Time 2 Sec MST00 Spanning tree Protocol has been enabled MST00 is executing the mstp compatible Multiple Spanning Tree Protocol Bridge Id Priority 32768 Address 00:01:02:03:04:01 Max age is 20 sec, forward delay is 15 sec Hello Time is 2 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Enabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Alternate Discarding 2000 128 P2P po1 Root Forwarding 1900 128 P2P
| `SEFOS#` show spanning-tree blockedports `` `Blocked Interfaces List:` `` `The Number of Blocked Ports in the system is :1` `` `SEFOS#` show spanning-tree pathcost method `` `spanning-tree port pathcost method is Long` `` `SEFOS#` show spanning-tree summary `` `spanning-tree enabled protocol is RSTP` `spanning-tree port pathcost method is Long` `` `RSTP Port Roles and States`
| `Port-Index Port-Role Port-State Port-Status` `---------- --------- ---------- -----------` `1 Designated Forwarding Enabled` `2 Designated Forwarding Enabled` `3 Designated Forwarding Enabled` `4 Designated Forwarding Enabled` `5 Designated Forwarding Enabled` `6 Designated Forwarding Enabled` `7 Designated Forwarding Enabled` `8 Designated Forwarding Enabled` `` `` `Multiple Instance:`
| `SEFOS#` show spanning-tree Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 1900 Port 73 [po1] Max age 20 Sec, forward delay 15 Sec Hello Time 2 Sec MST00 Spanning tree Protocol has been enabled MST00 is executing the mstp compatible Multiple Spanning Tree Protocol Bridge Id Priority 32768 Address 00:01:02:03:04:01 Max age is 20 sec, forward delay is 15 sec Hello Time is 2 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Enabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Alternate Discarding 2000 128 P2P po1 Root Forwarding 1900 128 P2P ``
| `SEFOS#` show spanning-tree summary `Switch - default`
| `spanning-tree port pathcost method is Long` `spanning-tree enabled protocol is MSTP` `` `MST00 Port Roles and States` `Port-Index Port-Role Port-State Port-Status` `---------- --------- ---------- -----------` `49 Disabled Forwarding Disabled` `` `Switch - cust1` `` `spanning-tree port pathcost method is Long`
| `spanning-tree enabled protocol is MSTP` `` `MST00 Port Roles and States` `Port-Index Port-Role Port-State Port-Status` `---------- --------- ---------- -----------` `1 Designated Forwarding Enabled` `2 Root Forwarding Enabled` `3 Designated Forwarding Enabled` `4 Disabled Discarding Enabled` `5 Disabled Discarding Enabled` `6 Disabled Discarding Enabled`
| `Switch - cust2` `` `spanning-tree port pathcost method is Long` `spanning-tree enabled protocol is MSTP` `MST00 Port Roles and States` `Port-Index Port-Role Port-State Port-Status` `---------- --------- ---------- -----------` `7 Designated Forwarding Enabled` `8 Root Forwarding Enabled` `9 Alternate Discarding Enabled` `10 Disabled Discarding Enabled` `11 Disabled Discarding Enabled` `12 Disabled Discarding Enabled`
Notes | This command is the same for both RSTP and MSTP.

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- spanning-tree - Enables the spanning-tree operation

- spanning-tree compatibility - Sets the compatibility version for the spanning-tree protocol

- spanning-tree timers - Sets the spanning-tree timers

- spanning-tree transmit hold-count - Sets the transmit hold-count value

- spanning-tree priority - Sets the bridge priority for the spanning-tree only in steps of 4096

- spanning-tree - Properties of an interface - Sets spanning-tree properties of an interface

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

- show spanning-tree bridge - Displays the spanning-tree configuration of the bridge

- show spanning-tree interface - Displays spanning-tree port configuration

### 4.5.28 `show spanning-tree redundancy`

Displays spanning-tree information.

    show spanning-tree [{summary | blockedports | pathcost method | redundancy}] [switch context-name]

Syntax Description | summary - Summary of port states. blockedports - Blocked ports in the system. pathcost method - Path cost method configured for a bridge. switch context-name - Context or switch name. This parameter is specific to multiple instance.
Mode | Privileged EXEC
Defaults | When SEFOS boots up, spanning-tree is enabled by default with MSTP operating in the switch.
Example | `SEFOS#` show spanning-tree redundancy Port Role/State for Instance 0 Port 1 ====================== Port Role 3 Port State 5 Port Role/State for Instance 0 Port 2 ====================== Port Role 1 Port State 2
| Dumping Data On Port 1 ------------------------ RootId 0:00:11:22:33:44:55 Designated BrId 0:00:11:22:33:44:55 Root path Cost 0 Length 0 Protocol Id 0 Port Id 8001 Message Age 0
| Max Age 14 Hello Time 2 Fwd Delay Time f Dest Addr 00:00:00:00:00:00 Src Addr 00:00:00:00:00:00 Version Length 0 Version 2 BPDU Type 2 Flags e
| Dumping Data On Port 2 ------------------------ RootId 0:00:11:22:33:44:55 Designated BrId 0:00:11:22:33:44:55 Root path Cost 0 Length 0 Protocol Id 0 Port Id 8002 Message Age 0
| Max Age 14 Hello Time 2 Fwd Delay Time f Dest Addr 00:00:00:00:00:00 Src Addr 00:00:00:00:00:00 Version Length 0 Version 2 BPDU Type 2 Flags e
| Instance 0 Port 1 ====================== Expected FdWile expiry time 0 Expected rcvdInfo exp Time 4654 Expected rrWhile exp Time 0 Expected rbWhile exp Time 0 Expected tcWhile exp Time 0 Instance 0 Port 1 TCN Var 1 STP Version 1 Proposing Flag 0 Info Is 4
| Instance 0 Port 2 ====================== Expected FdWile expiry time 0 Expected rcvdInfo exp Time 4656 Expected rrWhile exp Time 0 Expected rbWhile exp Time 0 Expected tcWhile exp Time 0 Instance 0 Port 2 TCN Var 1 STP Version 1 Proposing Flag 0 Info Is 4
Notes | This command is the same for both RSTP and MSTP.

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- spanning-tree - Enables the spanning-tree operation

- spanning-tree compatibility - Sets the compatibility version for the spanning-tree protocol

- spanning-tree timers - Sets the spanning-tree timers

- spanning-tree transmit hold-count - Sets the transmit hold-count value

- spanning-tree priority - Sets the bridge priority for the spanning-tree only in steps of 4096

- spanning-tree - Properties of an interface - Sets spanning-tree properties of an interface

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

- show spanning-tree bridge - Displays the spanning-tree configuration of the bridge

- show spanning-tree interface - Displays spanning-tree port configuration

### 4.5.29 `show spanning-tree detail`

Displays detailed spanning-tree information.

    show spanning-tree detail [switch context-name]

Syntax Description | switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | `SEFOS#` show spanning-tree detail
| Spanning tree Protocol has been enabled MST00 is executing the mstp compatible Multiple Spanning Tree Protocol Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01 Configured Max age 20 sec, Forward delay 15 sec Configured Hello Time 2 sec Dynamic Path Cost Disabled Flush Interval 0 centi-sec, Flush Invocations 72 Flush Indication threshold 0 Current Root has priority 32768, address 00:02:02:03:04:01 cost of root path is 2000 Number of Topology Changes 1, Time since topology Change 89 seconds ago Transmit Hold-Count 3 Root Times : Max age 20 Sec Forward delay 15 Sec
| Port 45 [Ex0/45] of MST00 is Root , Forwarding Ex0/45 is operating in the MSTP Mode Port path cost 2000, Port priority 128, Port Identifier 128.45. Port HelloTime 2, Timers: Hello - 1, Forward Delay - 0, Topology Change - 0 Designated root has priority 32768, address 00:02:02:03:04:01
| Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.45, Designated pathcost is 0 Operational Forward delay 15, Max age 20 Received Hello Time 2 Sec Number of Transitions to forwarding State : 1 Auto-Edge is enabled PortFast is disabled, Oper-Edge is disabled
| Link type is point to Point BPDUs : sent 4, recieved 4466 Restricted Role is disabled. Restricted TCN is disabled. bpdu-transmit enabled bpdu-receive enabled Loop Guard is disabled

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- spanning-tree - Enables the spanning-tree operation

- spanning-tree compatibility - Sets the compatibility version for the spanning-tree protocol

- spanning-tree timers - Sets the spanning-tree timers

- spanning-tree transmit hold-count - Sets the transmit hold-count value

- spanning-tree priority - Sets the bridge priority for the spanning-tree only in steps of 4096

- spanning-tree - Properties of an interface - Sets spanning-tree properties of an interface

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

- show spanning-tree bridge - Displays the spanning-tree configuration of the bridge

- show spanning-tree interface - Displays spanning-tree port configuration

### 4.5.30 `show spanning-tree active`

Displays spanning-tree information of active ports.

    show spanning-tree active [detail] [switch context-name]

Syntax Description | detail - Displays in detail about the port and bridge. This includes designated bridge details, designated port details, timer values, root bridge, and so on. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree active Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port 45 [Ex0/45] Max age 20 Sec, forward delay 15 Sec Hello Time 2 Sec MST00 Spanning tree Protocol has been enabled MST00 is executing the stp compatible Multiple Spanning Tree Pr otocol Bridge Id Priority 32768 Address 00:01:02:03:04:01 Max age is 20 sec, forward delay is 15 sec
| Hello Time is 2 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ---- Ex0/45 Root Learning 2000 128 P2P
| SEFOS# show spanning-tree active switch default Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port 45 [Ex0/45] Max age 20 Sec, forward delay 15 Sec Hello Time 2 Sec MST00 Spanning tree Protocol has been enabled MST00 is executing the stp compatible Multiple Spanning Tree Pr otocol Bridge Id Priority 32768 Address 00:01:02:03:04:01 Max age is 20 sec, forward delay is 15 sec Hello Time is 2 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ----- Ex0/45 Root Learning 2000 128 P2P

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- spanning-tree - Enables the spanning-tree operation

- spanning-tree compatibility - Sets the compatibility version for the spanning-tree protocol

- spanning-tree timers - Sets the spanning-tree timers

- spanning-tree transmit hold-count - Sets the transmit hold-count value

- spanning-tree priority - Sets the bridge priority for the spanning-tree only in steps of 4096

- spanning-tree - Properties of an interface - Sets spanning-tree properties of an interface

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

- show spanning-tree bridge - Displays the spanning-tree configuration of the bridge

- show spanning-tree interface - Displays spanning-tree port configuration

### 4.5.31 `show spanning-tree interface`

Diplays spanning-tree port configuration.

    show spanning-tree interface interface-type interface-id [{cost | priority | portfast | rootcost | restricted-role | restricted-tcn | state | stats | detail}]

Syntax Description | cost - spanning-tree port cost state - spanning-tree state stats - Displays the input and output packets by switching path for the interface priority - spanning-tree port priority portfast - spanning-tree portfast state rootcost - spanning-tree rootcost (pathcost to reach the root ) value restricted-role - Spanning-tree Restricted Role restricted-tcn - Spanning-tree Restricted Topology Change detail - Displays in detail about the port and bridge
Mode | Privileged EXEC
Example | `SEFOS#` show spanning-tree interface extreme-ethernet 0/1 Instance Role State Cost Prio Type -------- ---- ----- ---- ---- ---- MST00 Root Forwarding 200000 128.1 SharedLan SEFOS# show spanning-tree interface extreme-ethernet 0/1 cost Port cost is 200000 SEFOS# show spanning-tree interface extreme-ethernet 0/1 priority Port Priority is 128
| `SEFOS#` show spanning-tree interface extreme-ethernet 0/1 portfast `` `PortFast is disabled` `` `SEFOS#` show spanning-tree interface extreme-ethernet 0/1 rootcost `` `Root Cost is 200000` `` `SEFOS#` show spanning-tree interface extreme-ethernet 0/1 state `` `Forwarding`
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 stats Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1 Number of RSTP BPDU Count received : 1692 Number of Config BPDU Count received : 9 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 735 Number of Config BPDU Count Transmitted : 11 Number of TCN BPDU Count Transmitted : 0 Number of Invalid BPDU Count Transmitted : 0 Port Protocol Migration Count : 1
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 detail Port 1 [Ex0/1] of MST00 is Alternate , Discarding Ex0/1 is operating in the MSTP Mode Port path cost 2000, Port priority 128, Port Identifier 128.1. Port HelloTime 2, Timers: Hello - 1, Forward Delay - 0, Topology Change - 0 Designated root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.1, Designated pathcost is 0 Operational Forward delay 15, Max age 20 Received Hello Time 2 Sec Number of Transitions to forwarding State : 1 Auto-Edge is disabled PortFast is disabled, Oper-Edge is disabled Link type is point to Point BPDUs : sent 19, recieved 484 Restricted Role is disabled. Restricted TCN is disabled. bpdu-transmit enabled bpdu-receive enabled Loop Guard is enabled
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 restricted-role Restricted Role is Disabled SEFOS# show spanning-tree interface extreme-ethernet 0/1 restricted-tcn Restricted TCN is Disabled
| Multiple Instance: SEFOS# show spanning-tree interface extreme-ethernet 0/1 Switch - default Role State Cost Prio Type ---- ----- ---- ---- ---- Root Forwarding 200000 128 SharedLan SEFOS# show spanning-tree interface extreme-ethernet 0/1 cost Port cost is 200000 Switch - default
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 priority Switch - default Port Priority is 128 SEFOS# show spanning-tree interface extreme-ethernet 0/1 portfast Switch - default PortFast is disabled
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 rootcost Switch - default Root Cost is 200000 SEFOS# show spanning-tree interface extreme-ethernet 0/1 state Switch - default Forwarding SEFOS# show spanning-tree interface extreme-ethernet 0/1 stats Switch - default
| Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1 Number of RSTP BPDU Count received : 1692 Number of Config BPDU Count received : 9 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 735 Number of Config BPDU Count Transmitted : 11 Number of TCN BPDU Count Transmitted : 0 Number of Invalid BPDU Count Transmitted : 0 Port Protocol Migration Count : 1 SEFOS# show spanning-tree interface extreme-ethernet 0/1 detail Port 1 [Ex0/1] of MST00 is Root , Forwarding Ex0/1 is operating in the MSTP Mode Port path cost 2000, Port priority 128, Port Identifier 128.1. Port HelloTime 2, Timers: Hello - 0, Forward Delay - 0, Topology Change - 0 Designated root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address
| 00:02:02:03:04:01 Designated Port Id is 128.1, Designated pathcost is 0 Operational Forward delay 15, Max age 20 Received Hello Time 2 Sec Number of Transitions to forwarding State : 2 Auto-Edge is enabled PortFast is disabled, Oper-Edge is disabled Link type is point to Point BPDUs : sent 21, recieved 1331 Restricted Role is disabled. Restricted TCN is disabled. bpdu-transmit enabled bpdu-receive enabled Loop Guard is disabled
| SEFOS# show spanning-tree interface fast 0/1 restricted-role Switch - default Restricted Role is Disabled SEFOS# show spanning-tree interface fast 0/1 restricted-tcn Switch - default Restricted TCN is Disabled
Notes | Enter each interface separated by a space. Ranges are not supported. Valid interfac es include physical ports. VLANs, and port channels.

#### Related Commands

- spanning-tree mst - Properties of an interface for MSTP - Sets spanning-tree properties of an interface

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

- clear spanning-tree detected protocols - Restarts the protocol migration process on all the interfaces

- clear spanning-tree counters - Resets all bridge and port level statistics counters

### 4.5.32 `show spanning-tree root`

Displays spanning-tree root information.

    show spanning-tree root [{address | cost | forward-time | id | max-age | port | priority | detail }] [switch context-name]

Syntax Description | address - Root bridge MAC address. cost - Cost value associated with the port. forward-time - Root bridge forward time. id - Root bridge identifier. max-age - Root bridge maximum age port - Root port priority - Root bridge priority detail - Displays in detail about the port and bridge. This information includes designated bridge details, designated port details, timer values, root bridge, and so on. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | Single Instance: `SEFOS#` show spanning-tree root Root ID RootCost MaxAge FwdDly RootPort ------- -------- ------ ------ -------- 80:00:00:01:02:03:04:11 0 20 15 0 SEFOS# show spanning-tree root address Root Bridge Address is 00:01:02:03:04:11
| SEFOS# show spanning-tree root cost Root Cost is 0 SEFOS# show spanning-tree root forward-time Forward delay is 15 sec
| SEFOS# show spanning-tree root id Root Bridge Id is 80:00:00:01:02:03:04:11 SEFOS# show spanning-tree root max-age Root MaxAge is 20 SEFOS# show spanning-tree root port Root Port is 0
| SEFOS# show spanning-tree root priority Root Priority is 32768 SEFOS# show spanning-tree root detail We are the root of the spanning-tree Root Id Priority 32768 Address 00:01:02:03:04:11 Cost 0 Port 0 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec
| Multiple Instance: SEFOS# show spanning-tree root Switch - default Instance Root ID RootCost MaxAge FwdDly RootPort -------- ------- -------- ------ ------ -------- MST00 80:00:00:01:02:03:04:01 0 20 15 0 Switch - cust1
| Instance Root ID RootCost MaxAge FwdDly RootPort -------- ------- -------- ------ ------ -------- MST00 00:00:00:01:02:03:04:04 200000 20 15 Ex0/2

#### Related Commands

- spanning-tree timers - Sets the spanning-tree Timers

- spanning-tree priority - Sets the Bridge Priority for the spanning-tree only in steps of 4096

- show spanning-tree detail - Displays detailed spanning-tree information

### 4.5.33 `show spanning-tree bridge`

Displays the spanning-tree configuration of the bridge.

    show spanning-tree bridge [{address | forward-time | hello-time | id | max-age | protocol | priority | detail}] [switch context-name]

Syntax Description | address - Bridge address. forward-time - Bridge forward time. hello-time - Bridge hello time. id - Bridge identifier. max-age - Bridge maximum age. protocol - spanning-tree protocol. priority - Bridge priority. detail - Bridge detail. switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree bridge address Bridge Address is 00:01:02:03:04:21 SEFOS# show spanning-tree bridge forward-time Bridge Forward delay is 15 sec SEFOS# show spanning-tree bridge Bridge ID HelloTime MaxAge FwdDly Protocol --------- --------- ------ ------ -------- 80:00:00:01:02:03:04:21 2 20 15 rstp SEFOS# show spanning-tree bridge hello-time Bridge Hello Time is 2 sec
| SEFOS# show spanning-tree bridge id Bridge ID is 80:00:00:01:02:03:04:21 SEFOS# show spanning-tree bridge max-age Bridge Max Age is 20 sec SEFOS# show spanning-tree bridge protocol Bridge Protocol Running is RSTP
| SEFOS# show spanning-tree bridge priority Bridge Priority is 32768 SEFOS# show spanning-tree bridge detail Bridge Id Priority 32768, Address 00:01:02:03:04:21 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec
| Multiple Instance: SEFOS# show spanning-tree bridge Switch - default MST Instance Bridge ID MaxAge FwdDly Protocol ------------ --------- ------ ------ -------- MST00 0 :00:00:01:02:03:04:01 20 15 mstp Switch - cust1
| MST Instance Bridge ID MaxAge FwdDly Protocol ------------ --------- ------ ------ -------- MST00 0 :00:00:01:02:03:04:02 20 15 mstp SEFOS# show spanning-tree bridge address Switch - default MST00 00:01:02:03:04:01 Switch - cust1 MST00 00:01:02:03:04:0
Notes | Expressions are case sensitive.

#### Related Commands

- spanning-tree timers - Sets the spanning-tree timers

- spanning-tree mst forward-time - Configures the forward timer of the spanning-tree

- spanning-tree mst max-age - Configures the max-age timer of the spanning-tree

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.34 `show spanning-tree mst` - CIST or Specified MST Instance

Displays multiple spanning-tree information for the CIST instance or specified MST instance.

    show spanning-tree mst [instance-id_1-64 | 4094] [detail] [switch context-name]

Syntax Description | instance-id_1-64 - Range of spanning-tree instances. detail - Spanning-tree MST instance specific details. switch contex-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree mst 1 ## MST01 Vlans mapped: 2 Bridge Address 00:01:02:03:04:11 Priority 32768 Root Address 00:01:02:03:04:11 Priority 32768 Root this switch for MST01 Interface Role Sts Cost Prio.Nbr Type --------- ---- --- ---- -------- ---- Ex0/1 Master Forwarding 200000 128.1 SharedLan SEFOS# show spanning-tree mst 1 detail ## MST01
| Vlans mapped: 2 Bridge Address 00:01:02:03:04:11 Priority 32768 Root Address 00:01:02:03:04:11 Priority 32768 Root this switch for MST01 Ex0/1 of MST01 is Master , Forwarding Port info port id 128.1 priority 128 cost 200000 Designated root address 00:01:02:03:04:11 priority 32768 cost 0 Designated bridge address 00:01:02:03:04:11 priority 32768 port id 128.1
| Multiple Instance: SEFOS# show spanning-tree mst 1 Switch - default ## MST01 Vlans mapped: 2 Bridge Address 00:01:02:03:04:11 Priority 32768 Root Address 00:01:02:03:04:11 Priority 32768 Root this switch for MST01 Interface Role Sts Cost Prio.Nbr Type --------- ---- --- ---- -------- ---- Ex0/1 Master Forwarding 200000 128.1 SharedLan
Notes | The option mst is available only when MSTP is the operational mode of the spanning-tree.

#### Related Commands

- instance - Maps VLANS to an MST instance

- spanning-tree priority - Sets the Bridge Priority for the spanning-tree only in steps of 4096

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

### 4.5.35 `show spanning-tree mst configuration`

Diplays multiple spanning-tree instance configuration.

    show spanning-tree mst configuration [switch context-name]

Syntax Description | switch context-name - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree mst configuration Name [00:01:02:99:99:99] Revision 0 Instance Vlans mapped -------- ------------------------------------------ 0 11-1024,1025-2048,2049-3072,3073-4094 1 - 2 - 4094 1-10 -------------------------------------------------------
| Multiple Instance: SEFOS# show spanning-tree mst configuration Switch - default Name [00:01:02:03:04:01] Revision 0 Instance Vlans mapped -------- ------------------------------------------ 0 1-1024,1025-2048,2049-3072,3073-4094 ------------------------------------------------------- Switch - cust1
| Name [00:01:02:03:04:02] Revision 0 Instance Vlans mapped -------- ------------------------------------------ 0 1-1024,1025-2048,2049-3072,3073-4094 -------------------------------------------------------

#### Related Commands

- name - Sets Configuration name

- revision - Sets the configuration revision number

- instance - Maps VLANs to an MST instance

### 4.5.36 `show spanning-tree mst` - Port Specific Information

Displays multiple spanning-tree port specific configuration.

    show spanning-tree mst [instance-id_1-64 ] interface interface-type interface-id [{stats | hello-time | detail}]

Syntax Description | instance-id - Range of spanning-tree instances. interface - Details about a particular interface. stats - Displays the input and output packets by switching path for the interface. hello-time - Determines how often the switch broadcasts its hello. message to other switches when it is the root of the spanning-tree. detail - Detailed multiple spanning-tree port specific configuration.
Mode | Privileged EXEC
Example | SEFOS# show spanning-tree mst 1 interface extreme-ethernet 0/1 Instance Role Sts Cost Prio.Nbr -------- ---- --- ---- -------- 1 Master Forwarding 200000 128.1 SEFOS# show spanning-tree mst 1 interface extreme-ethernet 0/1 stats MST01 Bpdus sent 2, Received 0 SEFOS# show spanning-tree mst 1 interface extreme-ethernet 0/1 hello-time MST01 2 SEFOS# show spanning-tree mst 1 interface extreme-ethernet 0/1 detail
| Ex0/1 of MST01 is Master , Forwarding Port info port id 128.1 priority 128 cost 200000 Designated root address 00:01:02:03:04:11 priority 32768 cost 0 Designated bridge address 00:01:02:03:04:11 priority 32768 port id 128.1
Notes | Valid interfaces include physical ports and port channels.

#### Related Commands

- instance - Maps VLANS to an MST instance

- spanning-tree mst hello-time - Sets the port based hello timer value

- spanning-tree - Properties of an interface - Sets spanning-tree properties of an interface

- show spanning-tree mst - CIST or Specified MST Instance - CIST or specified mst Instance- Displays multiple spanning-tree information for the CIST Instance or specified MST Instance

- show spanning-tree interface - Displays Spanning-tree port configuration

- clear spanning-tree detected protocols - Restarts the protocol migration process on all the interfaces

- clear spanning-tree counters - Resets all bridge and port level statistics counters

### 4.5.37 `show customer spanning-tree`

Displays the detailed customer spanning-tree information.

    show customer spanning-tree [cep interface interface-type interface-id] [{detail [active] | active [detail]}]

Syntax Description | cep interface interface-type interface-id - Customer edge port detail - Displays in detail about the port and bridge. This includes designated Bridge details, designated port details, timer values, root bridge, and so on. active - Displays the bridge and details of the active (active ports are those ports that are participating in the spanning-tree) ports.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show customer spanning-tree cep interface fast 0/1 Port [Ex0/1] We are the root of the spanning-tree Root Id Priority 65535 Address 00:01:02:03:04:01 Cost 0 Root Ports Hello Time 2 Sec, Max Age 0 Sec, Forward Delay 0 Sec Customer spanning-tree Enabled Protocol RSTP Bridge Id Priority 65535 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec
| Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ PEP-Service: 2 Designated Forwarding 128 32 SharedLan CEP-Ex0/1 Designated Forwarding 200000 32 SharedLan SEFOS# show customer spanning-tree Port [Ex0/1] We are the root of the spanning-tree Root Id Priority 65535 Address 00:01:02:03:04:01 Cost 0 Root Ports Hello Time 2 Sec, Max Age 0 Sec, Forward Delay 0 Sec
| Customer spanning-tree Enabled Protocol RSTP Bridge Id Priority 65535 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ PEP-Service: 2 Designated Forwarding 128 32 SharedLan CEP-Ex0/1 Designated Forwarding 200000 32 SharedLan -------------------------------------------------------
| Multiple Instance: SEFOS# show customer spanning-tree Switch default Port [Ex0/1] We are the root of the spanning-tree Root Id Priority 65535 Address 00:01:02:03:04:01 Cost 0 Root Ports Hello Time 2 Sec, Max Age 0 Sec, Forward Delay 0
| Sec Customer spanning-tree Enabled Protocol RSTP Bridge Id Priority 65535 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ PEP-Service: 2 Designated Forwarding 128 32 SharedLan CEP-Ex0/1 Designated Forwarding 200000 32 SharedLan SEFOS# show customer spanning-tree cep interface fastethernet 0/1 Switch default
| Port [Ex0/1] We are the root of the spanning-tree Root Id Priority 65535 Address 00:01:02:03:04:01 Cost 0 Root Ports Hello Time 2 Sec, Max Age 0 Sec, Forward Delay 0 Sec Customer spanning-tree Enabled Protocol RSTP Bridge Id Priority 65535
| Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ PEP-Service: 2 Designated Forwarding 128 32 SharedLan CEP-Ex0/1 Designated Forwarding 200000 32 SharedLan
Notes | The port must be configured as CEP.

#### Related Commands

show customer spanning-tree - Displays the detailed customer spanning information

### 4.5.38 `spanning-tree mode-mst|rst|pvrst|pvst`

Sets the spanning-tree operating mode. The `no` form of the command sets the default spanning-tree operating mode.

    spanning-tree mode {mst | rst | pvrst | pvst}

    no spanning-tree mode

Syntax Description | mst - Multiple spanning-tree configuration. rst - Rapid spanning-tree configuration. pvrst - Per-VLAN-rapid spanning-tree configuration. pvst - Per-VLAN-spanning-tree configuration. The keyword `pvst` is not supported.
Mode | Global Configuration
Defaults | mst
Example | `SEFOS(config)#` spanning-tree mode pvrst
Notes | When SEFOS boots up, spanning-tree is enabled by default with MSTP operating in the switch. This command starts and enables only the spanning-tree mode. However, port-roles and states are computed only after enabling the spanning-tree. If the user-input for the spanning-tree mode is different from the current mode of operation, SEFOS shuts down the operational spanning-tree and start the spanning-tree as per user-input. GVRP must be disabled for setting the spanning-tree mode as PVRST.

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.39 `spanning-tree vlan`

Configures spanning-tree on a per VLAN basis. The `no` form of the command is used to return to the default setting.

    spanning-tree vlan 1-4094 {forward-time 4-30 | hello-time 1-10 | max-age 6-40 | hold-count 1-10 | brg-priority 0-61440 | root {primary | secondary}}

    no spanning-tree vlan 1-4096 {forward-time | hello-time | max-age | hold-count | brg-priority | root}

Syntax Description | vlan-id - VLAN identifier associated with a spanning-tree instance. The range is 1 to 4094. forward-time - The range is 4 to 30 seconds. Sets the forward-delay time for the specified spanning-tree instance. The forwarding time controls how long each of the listening and learning states last before the interface begins forwarding. hello-time - The range is 1 to 10 seconds. Sets the interval between hello bridge protocol data units (BPDUs) sent by the switch. max-age - The range is 6 to 40 seconds. Sets the interval between messages the spanning-tree receives from the root switch. If a switch does not receive a BPDU message from the root switch within this interval, it recomputes the spanning-tree topology. hold-count - The range is 1 to 10. Sets the holding limit of the bridge. The bridge responds to the messages only when it is within the range of its hold-count. brg-priority - Sets the bridge priority for the given instance. root - Sets the spanning-tree root with two options: primary - Forces the switch to be the root bridge. secondary - Forces the switch to be the root switch when the primary root fails.
Mode | Global Configuration
Defaults | Spanning-tree is enabled on all VLANs. forward-delay - 15 seconds. hello-time - 2 seconds. max-age - 20 seconds. hold-count - 3 brg-priority - 32768 + vlan-id
Example | `SEFOS(config)#` no spanning-tree vlan 5 hello-time SEFOS(config)# spanning-tree vlan 20 forward-time 18

#### Related Commands

show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.40 `spanning-tree bpduguard`

Places an interface in the error-disabled state when it receives a bridge protocol data unit (BPDU). The `no` form of the command sets it to the default configuration of `bpduguard`.

    spanning-tree bpduguard {disable | enable}

    no spanning-tree bpduguard

Syntax Description | disable - Disables BPDU guard on the specified interface enable - Enables BPDU guard on the specified interface
Mode | Interface Configuration
Defaults | BPDU guard is disabled.
Example | SEFOS(config-if)# switchport mode trunk SEFOS(config-if)# spanning-tree bpduguard enable

### 4.5.41 `spanning-tree guard`

Enables root guard or loop guard on all the VLANs associated with the selected interface. The `no` form of the command is used to return to the default setting.

    spanning-tree guard {root | none | loop}

    no spanning-tree guard

Syntax Description | root - Enables root guard on the specified interface. Root guard restricts which interface is allowed to be the spanning-tree root port or the path-to-the-root for the switch. none - Disables root guard on the specified interface loop - Enables loop guard on the specified interface. Loop guard prevents alternate or root ports from becoming designated ports when a failure creates a unidirectional link.
Mode | Interface Configuration
Defaults | Root guard is disabled.
Example | SEFOS(config-if)# spanning-tree guard root
Notes | VLAN port mode should be configured as trunk port prior to the execution of this command.

#### Related Commands

switchport mode - Configures the VLAN port mode.

### 4.5.42 `spanning-tree encap`

Sets the encapsulation type on the interface. The no form of the command sets the encapsulation type to `dot1q`.

    spanning-tree encap {dot1q | ISL}

    no spanning-tree encap

Syntax Description | dot1q - Sets the encapsulation type as `dot1q` ISL - Sets the encapsulation type as ISL
Mode | Interface Configuration
Defaults | `dot1q` encapsulation is set.
Example | SEFOS(config-if)# switchport mode trunk SEFOS(config-if)# spanning-tree encap ISL

### 4.5.43 `spanning-tree vlan status`

Enables or disables the PVRST status of an instance on a port.

    spanning-tree vlan 1-4094 status {disable | enable}

Syntax Description | vlan-id 1-4094 - VLAN identifier disable - Disables the PVRST status for the VLAN-ID enable - Enables the PVRST status for the VLAN-ID
Mode | Interface Configuration
Defaults | PVRST status is enable
Example | SEFOS(config-if)# spanning-tree vlan 1 status disable

#### Related Commands

show spanning-tree vlan - interface - Displays spanning-tree port information

### 4.5.44 `spanning-tree vlan port-priority`

Sets port priority for the given VLAN. The `no` form of the command sets port priority for the given VLAN to the default value.

    spanning-tree vlan 1-4094 port-priority 0-240

    no spanning-tree vlan 1-4094 port-priority

Syntax Description | vlan - VLAN identifier port-priority - Port priority value
Mode | Interface Configuration
Defaults | port-priority - 128
Example | SEFOS(config-if)# spanning-tree vlan 1 port-priority 16

#### Related Commands

show spanning-tree vlan - interface - Displays spanning-tree port information

### 4.5.45 `spanning-tree vlan cost`

Sets port cost for the given VLAN. The `no` form of the command sets the spanning-tree VLAN cost to the default value.

    spanning-tree vlan 1-4094 cost 0-200000

    no spanning-tree vlan 1-4094 cost

Syntax Description | vlan - VLAN identifier. cost - Cost value per VLAN.
Mode | Interface Configuration
Defaults | Cost on the port is 200000.
Example | SEFOS(config-if)# spanning-tree vlan 1 cost 250

#### Related Commands

show spanning-tree vlan - interface - Displays spanning-tree port information

### 4.5.46 `show spanning-tree vlan - blockedports|pathcost|summary`

Displays spanning-tree information, such as summary, blocked ports, and path cost.

    show spanning-tree vlan 1-4094 [{active [detail] | blockedports | detail [active] | pathcost-method | summary}]

Syntax Description | vlan - VLAN identifier. active [detail] - Displays details about the port and bridge, including: designated bridge details, designated port details, timer values, root bridge, and so on. blockedports - Blocked ports in the system. detail [active] - Displays the bridge and details of the active ports (active ports are those ports that are participating in the spanning-tree). pathcost-method - spanning-tree port priority. summary - Summary of port states.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree vlan 1 active Spanning-tree for VLAN 1 Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port Ex0/46 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32769 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Root Forwarding 2000 128 P2P
| Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/1 Designated Forwarding 200000 128 SharedLan SEFOS# show spanning-tree vlan 1 active detail Spanning-tree for VLAN 1 Bridge is executing the rstp compatible PVRST Protocol Bridge Identifier has priority 32769, Address 00:01:02:03:04:01 Configured Hello time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Number of Topology Changes 1 Time since topology Change 0 seconds ago Transmit Hold-Count 3 Root Times: Max Age 20 Sec, Forward Delay 15 Sec, Hello Time 2 Sec Port 46 [Ex0/46] of VLAN 1 is Root , Forwarding Port PathCost 2000 , Port Priority 128 , Port Identifier 128.46 Designated Root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.46, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 3 , recieved 46
| SEFOS# show spanning-tree vlan 1 blockedports Blocked Interfaces List: Ex0/2,Ex0/3,Ex0/4,Ex0/5,Ex0/6,Ex0/7,Ex0/8,Ex0/9,Ex0/10, ...
| The Number of Blocked Ports in the system is :23 SEFOS# show spanning-tree vlan 1 detail active Spanning-tree for VLAN 1 Bridge is executing the rstp compatible PVRST Protocol Bridge Identifier has priority 32769, Address 00:01:02:03:04:01 Configured Hello time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Number of Topology Changes 1 Time since topology Change 0 seconds ago Transmit Hold-Count 3 Root Times: Max Age 20 Sec, Forward Delay 15 Sec, Hello Time 2 Sec
| Port 46 [Ex0/46] of VLAN 1 is Root , Forwarding Port PathCost 2000 , Port Priority 128 , Port Identifier 128.46 Designated Root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.46, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 3 , recieved 46
| SEFOS# show spanning-tree vlan 1 pathcost-method spanning-tree port pathcost method is Long SEFOS# show spanning-tree vlan 1 summary spanning-tree enabled protocol is PVRST Spanning-tree pathcost method is long PVRST Port Roles and States Port-Index Port-Role Port-State Port-Status ---------- --------- ---------- ----------- 1 Designated Forwarding Enabled 2 Designated Forwarding Enabled 3 Designated Discarding Enabled 4 Designated Discarding Enabled 5 Designated Discarding Enabled 6 Designated Discarding Enabled 7 Designated Discarding Enabled 8 Designated Discarding Enabled ...
| Multiple Instance: SEFOS# show spanning-tree Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port 45 [Ex0/45] Max age 20 Sec, forward delay 15 Sec Hello Time 2 Sec MST00 Spanning tree Protocol has been enabled MST00 is executing the stp compatible Multiple Spanning Tree Pr otocol Bridge Id Priority 32768 Address 00:01:02:03:04:01 Max age is 20 sec, forward delay is 15 sec Hello Time is 2 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ----- Ex0/45 Root Learning 2000 128 P2P
| SEFOS# show spanning-tree vlan 1 active Spanning-tree for VLAN 1 Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port Ex0/46 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32769 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Root Forwarding 2000 128 P2P
| SEFOS# show spanning-tree vlan 1 active detail switch default Spanning-tree for VLAN 1 Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port Ex0/46 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32769 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Root Forwarding 2000 128 P2P
| Port 46 [Ex0/46] of VLAN 1 is Root , Forwarding Port PathCost 2000 , Port Priority 128 , Port Identifier 128.46 Designated Root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.46, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 3 , recieved 235
| SEFOS# show spanning-tree vlan 1 blockedports switch default Switch default
| Blocked Interfaces List: The Number of Blocked Ports in the system is :0 SEFOS# show spanning-tree vlan 1 detail active switch default Spanning-tree for VLAN 1 Bridge is executing the rstp compatible PVRST Protocol Bridge Identifier has priority 32769, Address 00:01:02:03:04:01 Configured Hello time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Number of Topology Changes 1 Time since topology Change 0 seconds ago Transmit Hold-Count 3 Root Times: Max Age 20 Sec, Forward Delay 15 Sec, Hello Time 2 Sec
| Port 46 [Ex0/46] of VLAN 1 is Root , Forwarding Port PathCost 2000 , Port Priority 128 , Port Identifier 128.46 Designated Root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.46, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 3 , recieved 235
| SEFOS# show spanning-tree vlan 1 pathcost-method switch default Switch default spanning-tree port pathcost method is Long SEFOS# show spanning-tree vlan 1 summary switch default
| Switch default spanning-tree enabled protocol is PVRST Spanning-tree pathcost method is long PVRST Port Roles and States Port-Index Port-Role Port-State Port-Status ---------- --------- ---------- ----------- 1 Designated Discarding Enabled 2 Designated Forwarding Enabled
Notes | Enter each interface separated by a space. Ranges are not supported. Valid interfaces include physical ports, VLANs, and port channels.

### 4.5.47 `show spanning-tree vlan - bridge`

Displays the spanning-tree configuration of the bridge.

    show spanning-tree vlan 1-4094 bridge [{address | detail | forward-time | hello-time | id | max-age | priority [system-id] | protocol}]

Syntax Description | vlan - VLAN identifier. address - Bridge address. detail - Bridge detail. forward-time - Bridge forward time. hello-time - Bridge hello time. id - Bridge identifier. max-age - Bridge max age. priority - Bridge priority. system-id - Bridge system identifier. protocol - Spanning-tree protocol.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree vlan 1 bridge Bridge ID HelloTime MaxAge FwdDly Protocol --------- --------- ------ ------ -------- 80:00:00:01:02:03:04:01 2 20 15 Pvrst SEFOS# show spanning-tree vlan 1 bridge address Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge detail Bridge Id Priority 32769, Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec,
| Forward Delay 15 sec SEFOS# show spanning-tree vlan 1 bridge forward-time Bridge Forward delay is 15 sec SEFOS# show spanning-tree vlan 1 bridge hello-time Bridge Hello Time is 2 sec SEFOS# show spanning-tree vlan 1 bridge id Bridge ID is 80:00:00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge max-age Bridge Max Age is 20 sec
| SEFOS# show spanning-tree vlan 1 bridge priority Bridge Priority is 32769 SEFOS# show spanning-tree vlan 1 bridge priority system-id Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge protocol Bridge Protocol Running is PVRST
| Multiple Instance: SEFOS# show spanning-tree vlan 1 bridge switch default Switch default Bridge ID HelloTime MaxAge FwdDly Protocol --------- --------- ------ ------ -------- 80:00:00:01:02:03:04:01 2 20 15 Pvrst SEFOS# show spanning-tree vlan 1 bridge address Switch default
| Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge detail switch default Switch default Bridge Id Priority 32769, Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec SEFOS# show spanning-tree vlan 1 bridge forward-time switch default
| Switch default Bridge Forward delay is 15 sec SEFOS# show spanning-tree vlan 1 bridge hello-time switch default Switch default Bridge Hello Time is 2 sec SEFOS# show spanning-tree vlan 1 bridge id switch default Switch default
| Bridge ID is 80:00:00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge max-age switch default Switch default Bridge Max Age is 20 sec switch default SEFOS# show spanning-tree vlan 1 bridge priority Switch default Bridge Priority is 32769 SEFOS# show spanning-tree vlan 1 bridge priority system-id switch default
| Switch default Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 bridge protocol switch default Switch default Bridge Protocol Running is PVRST SEFOS# show spanning-tree vlan 1 bridge switch default Switch default
| Bridge ID HelloTime MaxAge FwdDly Protocol --------- --------- ------ ------ -------- 80:00:00:01:02:03:04:01 2 20 15 Pvrst
Notes | Expressions are case sensitive.

#### Related Commands

- spanning-tree mode mst|rst - Sets the spanning-tree operating mode

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.48 `show spanning-tree vlan - root`

Displays spanning-tree root information.

    show spanning-tree vlan 1-4094 root [{address | cost | detail | forward-time | hello-time | root-bridge-id | max-age | port | priority [system-id]}]

Syntax Description | vlan-id 1-4094 - VLAN identifier. address - Root bridge MAC address. cost - Cost value associated with the port. detail - Displays in detail about the port and bridge. This includes designated Bridge details, designated port details, timer values, root bridge, and so on. forward-time - Root bridge forward time. hello-time - Root bridge hello time. root-bridge-id - Root bridge identifier. max-age - Root bridge maximum age. port - Root port. priority - Root bridge priority. system-id - Root bridge system identifier.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree vlan 1 Spanning-tree for VLAN 1 Root Id Priority 32768 Address 00:02:02:03:04:01 Cost 2000 Port Ex0/46 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32769 Address 00:01:02:03:04:01 Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Dynamic Path Cost is Disabled Dynamic Path Cost Lag-Speed Change is Disabled Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/46 Root Forwarding 2000 128 P2P
| SEFOS# show spanning-tree vlan 1 root address Root Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 root cost Root Cost is 0 SEFOS# show spanning-tree vlan 1 root detail We are the root of the spanning-tree Root Id Priority 32769 Address 00:01:02:03:04:01 Cost 0 Port 0 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec
| SEFOS# show spanning-tree vlan 1 root forward-time Forward delay is 15 sec SEFOS# show spanning-tree vlan 1 root hello-time Hello Time is 2 sec SEFOS# show spanning-tree vlan 1 root id Root Bridge Id is 80:01:00:01:02:03:04:01
| SEFOS# show spanning-tree vlan 1 root max-age Root MaxAge is 20 SEFOS# show spanning-tree vlan 1 root port Root Port is 0 SEFOS# show spanning-tree vlan 1 root priority Root Priority is 32769
| Multiple Instance: SEFOS# show spanning-tree vlan 1 root switch default Switch default Root ID RootCost HelloTime MaxAge FwdDly RootPort ------- -------- --------- ------ ------ -------- 80:01:00:01:02:03:04:01 0 2 20 15 0 SEFOS# show spanning-tree vlan 1 root address switch default
| Switch default Root Bridge Address is 00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 root cost Switch default Root Cost is 0 SEFOS# show spanning-tree vlan 1 root detail switch default Switch default We are the root of the spanning-tree Root Id Priority 32769 Address 00:01:02:03:04:01 Cost 0 Port 0 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec
| SEFOS# show spanning-tree vlan 1 root forward-time Switch default
| Forward delay is 15 sec SEFOS# show spanning-tree vlan 1 root hello-time switch default Switch default Hello Time is 2 sec SEFOS# show spanning-tree vlan 1 root id switch default Switch default Root Bridge Id is 80:01:00:01:02:03:04:01 SEFOS# show spanning-tree vlan 1 root max-age switch default Switch default
| Root MaxAge is 20 SEFOS# show spanning-tree vlan 1 root port switch default Switch default Root Port is 0 SEFOS# show spanning-tree vlan 1 root priority switch default Switch default Root Priority is 32769 SEFOS# show spanning-tree vlan 1 root priority system-id switch default Switch default

#### Related Commands

- spanning-tree vlan - Configures spanning-tree on a per-VLAN basis

- show spanning-tree detail - Displays detailed spanning-tree information

### 4.5.49 `show spanning-tree vlan - interface`

Displays instance specific interface information.

    show spanning-tree vlan 1-4094 interface ifXtype ifnum [{cost | detail | priority | rootcost | state | stats}]

Syntax Description | vlan - VLAN identifier. ifXtype - Interface type. ifnum - Interface number. cost - Spanning-tree port cost. detail - Displays detaisl about the port and bridge. priority - Spanning-tree port priority. rootcost - Spanning-tree root cost value (path cost to reach the root). state - Spanning-tree state. stats - Displays input and output packets by switching path for the interface
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 Role State Cost Prio ---- ----- ---- ---- Designated Forwarding 200000 128 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 cost Port cost is 200000 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 detail
| Port 1 [Ex0/1] of VLAN 1 is Designated, Forwarding Port PathCost 200000 , Port Priority 128 , Port Identifier 128.1 Designated Root has priority 32769, address 00:01:02:03:04:01 Designated Bridge has priority 32769, address 00:01:02:03:04:01 Designated Port Id is 128.1, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 59 , recieved 0
| SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 priority
| Port Priority is 128 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 rootcost Root Cost is 0 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 state Forwarding SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 stats Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1
| Number of RSTP BPDU Count received : 0 Number of Config BPDU Count received : 0 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 97 Number of Config BPDU Count Transmitted : 0 Number of TCN BPDU Count Transmitted : 0 Port Protocol Migration Count : 0
| Multiple Instance: SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 cost Switch default Port cost is 200000 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 detail
| Switch default Port 1 [Ex0/1] of VLAN 1 is Designated, Forwarding Port PathCost 200000 , Port Priority 128 , Port Identifier 128.1
| Designated Root has priority 32769, address 00:01:02:03:04:01 Designated Bridge has priority 32769, address 00:01:02:03:04:01 Designated Port Id is 128.1, Designated PathCost 0 Timers: Hello Time - 2, MaxAge - 20, Forward Delay - 15, Hold - 1 No of Transitions to forwarding State :1 BPDUs : sent 233 , recieved 0 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 priority Switch default
| Port Priority is 128 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 rootcost Switch default Root Cost is 0 SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 state Switch default Forwarding SEFOS# show spanning-tree vlan 1 interface extreme-ethernet 0/1 stats
| Switch default Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1 Number of RSTP BPDU Count received : 0 Number of Config BPDU Count received : 0 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 261 Number of Config BPDU Count Transmitted : 0 Number of TCN BPDU Count Transmitted : 0 Port Protocol Migration Count : 0

#### Related Commands

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

### 4.5.50 `show spanning-tree interface`

Displays the spanning-tree port configuration.

This command is an extension of the `show spanning-tree interface` command. Additional options `bpduguard`, `encapsulation type`, and `rootguard` are added for PVRST.

    show spanning-tree interface interface-type interface-id [{bpduguard | cost | encapsulationtype | priority | portfast | rootcost | rootguard | restricted-role | restricted-tcn | state | stats | detail}]

Syntax Description | bpduguard - Spanning-tree BPDU guard. cost - Spanning-tree port cost. encapsulationtype - spanning-tree encapsulation type. state - Spanning-tree state. stats - Displays input and output packets per switching path for the interface. priority - Spanning-tree port priority. portfast - Spanning-tree portfast state. rootcost - Spanning-tree rootcost (pathcost to reach the root ) value. rootguard - Spanning-tree rootguard. restricted-role - Spanning-tree restricted role. restricted-tcn - Spanning-tree restricted topology change. detail - Displays details about the port and bridge.
Mode | Privileged EXEC
Example | Single Instance: SEFOS# show spanning-tree interface extreme-ethernet 0/1 Role State Cost Prio Type ---- ----- ---- ---- ---- Root Forwarding 200000 128 SharedLan SEFOS# show spanning-tree interface extreme-ethernet 0/1 cost
| Port cost is 200000 SEFOS# show spanning-tree interface extreme-ethernet 0/1 priority Port Priority is 128 SEFOS# show spanning-tree interface extreme-ethernet 0/1 portfast PortFast is disabled SEFOS# show spanning-tree interface extreme-ethernet 0/1 rootcost Root Cost is 200000
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 state Forwarding SEFOS# show spanning-tree interface extreme-ethernet 0/1 stats Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1 Number of RSTP BPDU Count received : 1692 Number of Config BPDU Count received : 9 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 735 Number of Config BPDU Count Transmitted : 11 Number of TCN BPDU Count Transmitted : 0 Number of Invalid BPDU Count Transmitted : 0 Port Protocol Migration Count : 1
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 detail Port 1 [Ex0/1] of MST00 is Alternate, Discarding Ex0/1 is operating in the MSTP Mode Port path cost 2000, Port priority 128, Port Identifier 128.1. Port HelloTime 2, Timers: Hello - 1, Forward Delay - 0, Topology Change - 0 Designated root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.1, Designated pathcost is 0 Operational Forward delay 15, Max age 20 Received Hello Time 2 Sec Number of Transitions to forwarding State : 1 Auto-Edge is disabled PortFast is disabled, Oper-Edge is disabled Link type is point to Point BPDUs : sent 19, recieved 484 Restricted Role is disabled. Restricted TCN is disabled. bpdu-transmit enabled bpdu-receive enabled Loop Guard is enabled
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 restricted-role Restricted Role is Disabled SEFOS# show spanning-tree interface extreme-ethernet 0/1 restricted-tcn Restricted TCN is Disabled
| Multiple Instance: SEFOS# show spanning-tree interface extreme-ethernet 0/1 Switch - default Role State Cost Prio Type ---- ----- ---- ---- ---- Root Forwarding 200000 128 SharedLan SEFOS# show spanning-tree interface extreme-ethernet 0/1 cost Port cost is 200000 Switch - default SEFOS# show spanning-tree interface extreme-ethernet 0/1 priority
| Switch - default Port Priority is 128 SEFOS# show spanning-tree interface extreme-ethernet 0/1 portfast Switch - default PortFast is disabled SEFOS# show spanning-tree interface extreme-ethernet 0/1 rootcost Switch - default
| Root Cost is 200000 SEFOS# show spanning-tree interface extreme-ethernet 0/1 state Switch - default Forwarding SEFOS# show spanning-tree interface extreme-ethernet 0/1 stats Switch - default
| Statistics for Port Ex0/1 Number of Transitions to forwarding State : 1 Number of RSTP BPDU Count received : 1692 Number of Config BPDU Count received : 9 Number of TCN BPDU Count received : 0 Number of RSTP BPDU Count Transmitted : 735 Number of Config BPDU Count Transmitted : 11 Number of TCN BPDU Count Transmitted : 0 Number of Invalid BPDU Count Transmitted : 0 Port Protocol Migration Count : 1
| SEFOS# show spanning-tree interface extreme-ethernet 0/1 detail Port 1 [Ex0/1] of MST00 is Root , Forwarding Ex0/1 is operating in the MSTP Mode Port path cost 2000, Port priority 128, Port Identifier 128.1. Port HelloTime 2, Timers: Hello - 0, Forward Delay - 0, Topology Change - 0 Designated root has priority 32768, address 00:02:02:03:04:01 Designated Bridge has priority 32768, address 00:02:02:03:04:01 Designated Port Id is 128.1, Designated pathcost is 0 Operational Forward delay 15, Max age 20 Received Hello Time 2 Sec Number of Transitions to forwarding State : 2 Auto-Edge is enabled PortFast is disabled, Oper-Edge is disabled Link type is point to Point BPDUs : sent 21, recieved 1331 Restricted Role is disabled. Restricted TCN is disabled. bpdu-transmit enabled bpdu-receive enabled Loop Guard is disabled
| SEFOS# show spanning-tree interface fast 0/1 restricted-role Switch - default Restricted Role is Disabled SEFOS# show spanning-tree interface fast 0/1 restricted-tcn Switch - default Restricted TCN is Disabled

#### Related Commands

- spanning-tree mst - Properties of an interface for MSTP - Sets the spanning-tree properties of an interface for MSTP

- show spanning-tree detail - Displays detailed spanning-tree information

- show spanning-tree active - Displays spanning-tree information of active ports

- clear spanning-tree detected protocols - Restarts the protocol migration process on all the interfaces

- clear spanning-tree counters - Resets all bridge and port level statistics counters

### 4.5.51 `spanning-tree layer2-gateway-port`

Configures port as layer two gateway port. The `no` form of the command withdraws layer two gateway port status.

    spanning-tree layer2-gateway-port

    no spanning-tree layer2-gateway-port

Mode | Interface Configuration
Defaults | By default, the port is not configured as layer two gateway port.
Example | SEFOS(config-if)# spanning-tree layer2-gateway-port
Notes | The BPDU transmit status of the port must be disabled before configuring the port as layer two gateway port.

#### Related Commands

- show spanning-tree detail - Displays in detail about the spanning-tree port and bridge configuration.

- spanning-tree layer2-gateway-port - Displays spanning-tree layer two gateway port specific configuration.

### 4.5.52 `spanning-tree bpdu-receive`

Configures the BPDU receive status of the port.

    spanning-tree bpdu-receive {enabled | disabled}

Syntax Description | enabled - Receives the BPDUs on the port. disabled - Ignores the BPDUs received on the port.
Mode | Interface Configuration
Defaults | Enabled.
Example | SEFOS(config-if)# spanning-tree bpdu-receive enabled

#### Related Commands

- show spanning-tree detail - Displays in detail about the spanning-tree port and bridge configuration.

### 4.5.53 `spanning-tree bpdu-transmit`

Configures BPDU transmit status of the port.

    spanning-tree bpdu-transmit {enabled | disabled}

Syntax Description | enabled - The port transmits BPDUs. disabled - The port does not transmit BPDUs.
Mode | Interface Configuration
Defaults | Enabled.
Example | SEFOS(config-if)# spanning-tree bpdu-transmit enabled
Notes | The BPDU transmit status of the port must be disabled before configuring the port as layer two gateway port.

#### Related Commands

- show spanning-tree detail - Displays in detail about the spanning-tree port and bridge configuration.

### 4.5.54 `spanning-tree bpdufilter`

Enables or disables the BPDU filter on an interface. The `no` form of the command returns to the default setting.

This command operates similar to that of the spanning-tree bpdu-receive and spanning-tree bpdu-transmit commands.

    spanning-tree bpdufilter {disable | enable}

    no spanning-tree bpdufilter

Syntax Description | enable - Enables BPDU filtering on the interface. disable - Disables BPDU filtering on the interface.
Mode | Interface Configuration
Defaults | Disabled.
Example | SEFOS(config-if)# spanning-tree bpdufilter enable
Notes | The BPDU transmit status of the port must be disabled before configuring the port as layer two gateway port.

#### Related Commands

- show spanning-tree detail - Displays in detail about the spanning-tree port and bridge configuration.

### 4.5.55 `spanning-tree mst - pseudoRootID priority`

Sets the `pseudoroot` MAC address and priority for the spanning-tree in steps of 4096. The `no` form of the command resets the `pseudoroot` identifier for the spanning-tree to bridge identifier.

    spanning-tree [mst instance-id_1-64] pseudoRootID priority 0-61440 mac-address ucast-mac

    no spanning-tree [mst instance-id_1-64] pseudoRootId

Syntax Description | mst - Specifies the spanning-tree instance. This value ranges from 1 to 64. priority - Specifies the `pseudoroot` priority. This value ranges from 0 to 61440. mac-address - Specifies the `pseudoroot` unicast MAC address.
Mode | Interface Configuration
Defaults | Default bridge identifier is set for the spanning-tree.
Example | SEFOS(config-if)# spanning-tree mst 1 pseudoRootId priority 8192 mac-address 00:00:12:34:45:55
Notes | The `pseudoroot` identifier is used by layer two gateway port as the root identifier in generated BPDUs.

#### Related Commands

- show spanning-tree detail - Displays in detail about the spanning-tree port and bridge configuration

- spanning-tree layer2-gateway-port - Displays spanning-tree layer two gateway port specific configuration

### 4.5.56 `show spanning-tree interface layer2-gateway-port`

Displays the spanning-tree layer two gateway port specific configuration.

    show spanning-tree interface [interface-type interface-id] layer2-gateway-port [switch context_name]

Syntax Description | interface-type - Type of interface. interface-id - Interface identifier. switch - Context or switch name. This parameter is specific to multiple instance. The keyword `switch` is not supported.
Mode | Privileged EXEC
Example | SEFOS# show spanning-tree int extreme-ethernet 0/1 layer2-gateway-port Port Ex0/1 PseudoRootId Instance Priority MacAddress State ---------- ---------- ------------------- ---------- MST00 32768 00:01:02:99:99:99 Discarding MST01 8192 00:00:12:34:45:55 Forwarding

#### Related Commands

- spanning-tree layer2-gateway-port - Configures the port as layer two gateway port

- spanning-tree mst - pseudoRootID priority - Sets the pseudoroot MAC address and priority for the spanning-tree in steps of 4096

### 4.5.57 `spanning-tree mst max-instance`

Sets maximum MSTP instance value. The `no` form of the command resets maximum MSTP instance value.

    spanning-tree mst max-instance 1-64

    no spanning-tree mst max-instance

Mode | Global Configuration
Example | SEFOS(config)# spanning-tree mst max-instance 1

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