display stp

Function

The display stp command displays the status of and statistics about a spanning tree instance in a Multiple Spanning Tree Protocol (MSTP) process.

Format

display stp [ instance instance-id ] [ interface { interface-name | interface-type interface-number } | slot slot-id | vsi vsi-name pw pw-name ] [ brief ]

Parameters

Parameter	Description	Value
instance instance-id	Displays the status of and statistics about a spanning tree instance. If instance <instance-id> is not specified, the status of and statistics about all spanning tree instances will be displayed in the sequence of the interface numbers.	The value is an integer ranging from 0 to 4094, Value 0 indicates CIST.
interface interface-type interface-number	Displays information of a spanning tree on a specified interface. If interface <ifType> <ifNum> is not specified, the status of and statistics about all interfaces will be displayed in the sequence of the interface numbers.	-
slot slot-id	Specifies the number of the slot where the interface resides.	The value is a string of 1 to 23 case-sensitive characters, spaces not supported.
vsi vsi-name	Specifies the names of a virtual switching instance (VSI).	The vsi-name is a string of 1 to 31 case-sensitive characters, spaces not supported. When quotation marks are used around the string, spaces are allowed in the string.
pw pw-name	Specifies the names of a pseudo wire (PW).	The pw-name is a string of 1 to 15 case-sensitive characters, spaces not supported. When quotation marks are used around the string, spaces are allowed in the string.
brief	Displays the brief status.	-

Views

MSTP process view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mstp	write

Usage Guidelines

Usage Scenario

The display stp command is used to check whether the spanning tree protocol is run on the specified MSTP process.

If the Protocol Status field value is disabled, the spanning tree protocol is not run.
If STP/RSTP/MSTP has been run, information such as the working mode of the spanning tree protocol will be displayed.
When a network planner has deployed STP/RSTP/MSTP on the network, you can run the display stp command to check whether the configurations are correct and check the calculation result.

Example

The actual command output varies according to the device. The command output here is only an example.

# After run the stp enable command, display the status of and statistics about STP of MSTP process 1.

<HUAWEI> system-view
[~HUAWEI] stp process 1
[*HUAWEI-mst-process-1] display stp
-------[CIST Global Info][Mode MSTP]-------                                     
CIST Bridge         :32768.bc9c-31de-7489                                       
Config Times        :Hello 2s MaxAge 20s FwDly 15s MaxHop 20                    
Active Times        :Hello 2s MaxAge 20s FwDly 15s MaxHop 20                    
CIST Root/ERPC      :32768.bc9c-31de-7489 / 0 (This bridge is the root)         
CIST RegRoot/IRPC   :32768.bc9c-31de-7489 / 0 (This bridge is the root)         
CIST RootPortId     :0.0                                                        
BPDU-Protection     :Disabled                                                   
TC or TCN received  :0                                                          
TC count per hello  :0                                                          
STP Converge Mode   :Normal                                                     
Time since last TC  :0 days 0h:0m:0s                                            
Number of TC        :0                                                          
Topo Change Flag    :0

# When the stp enable command does not run, display the status of and statistics about STP on MSTP process 1.

<HUAWEI> system-view
[~HUAWEI] stp process 1
[*HUAWEI-mst-process-1] display stp
Protocol Status       :Disabled
 Protocol Standard     :IEEE 802.1s
 Version               :3
 CIST Bridge Priority  :32768
 MAC address           :00e0-fc12-3456
 Max age(s)            :20
 Forward delay(s)      :15
 Hello time(s)         :2
 Max hops              :20

**Table 1** Description of the **display stp** command output
Item	Description
CIST Bridge Priority	Priority of the switch in CIST.
CIST Global Info	CIST global information.
CIST Bridge	ID of the CIST bridge. The 16 left-most bits are the priority of the switch in CIST. The 48 right-most bits is the MAC address of the switch.
CIST Root/ERPC	CIST root bridge ID/External path cost (path cost from the switch to the CIST root bridge).
CIST RegRoot/IRPC	Region root bridge ID/Internal path cost (path cost from the switch to region root bridge).
CIST RootPortId	CIST root port ID. "0.0" indicates that the switch is a root bridge and has no root port.
Mode	The operation mode. The default mode is MSTP.
Config Times	Values configured manually in the BPDU: Hello: interval at which BPDUs are sent. MaxAge: maximum lifecycle of the BPDU. FwDly: forwarding delay timer. MaxHop: maximum hops in the MST region.
Active Times	Values used actually in the BPDU: Hello: interval at which BPDUs are sent. MaxAge: maximum lifecycle of the BPDU. FwDly: forwarding delay timer. MaxHop: maximum hops in the MST region.
BPDU-Protection	BPDU protection function: disabled. enabled.
TC or TCN received	Number of received topology change (TC) or topology change notification (TCN) BPDUs.
TC count per hello	Number of TC BPDUs received within a hello interval.
TC or TCN send	Number of TC or TCN BPDUs sent by the port.
STP Converge Mode	Convergence mode of the spanning tree protocol.
Time since last TC	Period from the last topology change to now.
Number of TC	Number of topology changes.
Topo Change Flag	Whether the topology is changed: 0: The topology is not changed. 1: The topology is changed.
Protocol Status	Status of the protocol.
Protocol Standard	Standards of the protocol.
Version	Protocol version: 0: STP. 2: RSTP. 3: MSTP.
MAC address	MAC address of the switch.
Max hops	Maximum hops in Multiple Spanning Tree (MST) region.
Max age(s)	Maximum lifecycle of the BPDU.
Forward delay(s)	Time interface status transition takes.
Hello time(s)	Interval at which BPDUs are sent from the root bridge.
Port Protocol	The status of the port protocol: enable: STP is enabled on the port. disable: STP is disabled on the port.
Port Role	In a CIST area, the four port roles are as follows: CIST Root Port. CIST Designated Port. CIST Alternate Port. CIST Backup Port.
Port Priority	Priority of the port.
Designated Bridge/Port	ID of the designated switch and port. The 16 left-most bits of the switch ID represent the priority of the switch in the CIST region; the 48 right-most bits represent the MAC address of the switch. The left-most 4 bits of the port ID represent the priority and the right-most 12 bits represent the port number.
Port Edged	Status of an edge port that is specified by the administrator. enabled. disabled. Config indicates that the value is configured by using the stp edged-port command. Active indicates the actual value.
Point-to-point	Link type of the port. Config indicates that the link type is configured using the stp point-to-point command. Active indicates the actual link type.
Transit Limit	Maximum number of the BPDUs sent by the current port before each Hello time expires.
Protection Type	Protection type , which can be: None: no protection. LoopBack: self-loop detection. BpduRoot: BPDU and root protection. ROOT: root protection. BPDU: BPDU protection. Loop: loop protection. BpduLoop: BPDU and loop protection.
Port STP Mode	STP mode on an interface.
Config-digest-snoop	Configuration digest snooping function: Displayed only after the stp config-digest-snoop command is configured to enable the configuration digest snooping function on the port. If the port does not have the function enabled, this field is not displayed. snooped=false: The configuration digest of the packets on the remote end is the same as that on the local end. snooped=true: The configuration digest of the packets on the remote end is different from that on the local end.
Port Protocol Type	Format of the packets that the interface receives and sends: auto. legacy. dot1s. The default value is auto. Config indicates that the packet format is configured using the stp compliance command. Active indicates the actual packet format.
BPDU Encapsulation	Format of the BPDUs received and sent through a port.
PortTimes	Values in the BPDUs on the interface: Hello: interval at which BPDUs are sent. MaxAge: maximum lifecycle of the BPDU. FwDly: forwarding delay timer. MaxHop: maximum hops in the MST region.
BPDU Sent	Statistics about sent BPDUs: TCN: topology change notification. Config: STP BPDUs. RST: RSTP BPDUs. MST: MSTP BPDUs.
BPDU Received	Statistics about received BPDUs.
Port Cost(Legacy)	Path cost of the port. It is calculated by dot1t algorithm. config: path cost manually configured. active: actual path cost.