Technical Documentation

show spanning-tree bridge

Syntax

show spanning-tree bridge<brief | detail><msti msti-id><routing-instance routing-instance-name><vlan-id vlan-id>

Syntax (EX Series Switch)

show spanning-tree bridge<brief | detail><msti msti-id><vlan-id vlan-id>

Release Information

Command introduced in Junos OS Release 8.4.

Command introduced in Junos OS Release 9.0 for EX Series switches.

Description

Display the configured or calculated Spanning Tree Protocol (STP) parameters.

Options

none: (Optional) Display brief STP bridge information for all multiple spanning-tree instances (MSTIs).
brief | detail: (Optional) Display the specified level of output.
msti msti-id: (Optional) Display STP bridge information for the specified MSTI.
routing-instance routing-instance-name: (Optional) Display STP bridge information for the specified routing instance.
vlan-id vlan-id: (Optional) Display STP bridge information for the specified VLAN.

Required Privilege Level

view

List of Sample Output

show spanning-tree bridge routing-instance
show spanning-tree bridge msti
show spanning-tree bridge vlan-id (MSTP)
show spanning-tree bridge (VSTP)
show spanning-tree bridge vlan-id (VSTP)
Output Fields
Table 1 lists the output fields for the show spanning-tree bridge command. Output fields are listed in the approximate order in which they appear.
Table 1: show spanning-tree bridge Output Fields
Field Name
Field Description
Routing instance name
Name of the routing instance under which the bridge is configured.
Enabled protocol
Spanning Tree Protocol type enabled.
Root ID
Bridge ID of the elected spanning tree root bridge. The bridge ID consists of a configurable bridge priority and the MAC address of the bridge.
Root cost
Calculated cost to reach the root bridge from the bridge where the command is entered.
Root port
Interface that is the current elected root port for this bridge.
CIST regional root
Bridge ID of the elected MSTP regional root bridge.
CIST internal root cost
Calculated cost to reach the regional root bridge from the bridge where the command is entered.
Hello time
Configured number of seconds between transmissions of configuration bridge protocol data units (BPDUs).
Maximum age
Configured maximum expected arrival time of hello bridge protocol data units (BPDUs).
Forward delay
Configured time an STP bridge port remains in the listening and learning states before transitioning to the forwarding state.
Hop count
Configured maximum number of hops a BPDU can be forwarded in the MSTP region.
Message age
Number of elapsed seconds since the most recent BPDU was received.
Number of topology changes
Total number of STP topology changes detected since the routing device last booted.
Time since last topology change
Number of elapsed seconds since the most recent topology change.
Bridge ID (Local)
Locally configured bridge ID. The bridge ID consists of a configurable bridge priority and the MAC address of the bridge.
Extended system ID
System identifier.
MSTI regional root
Bridge ID of the elected MSTP regional root bridge.
Sample Output
show spanning-tree bridge routing-instance
user@host> show spanning-tree bridge routing-instance vs1 detail
STP bridge parameters Routing instance name : vs1 Enabled protocol : MSTP STP bridge parameters for CIST Root ID : 32768.00:13:c3:9e:c8:80 Root cost : 0 Root port : xe-10/2/0 CIST regional root : 32768.00:13:c3:9e:c8:80 CIST internal root cost : 22000 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Hop count : 18 Message age : 0 Number of topology changes : 1 Time since last topology change : 1191 seconds Local parameters Bridge ID : 32768.00:90:69:0b:7f:d1 Extended system ID : 1 STP bridge parameters for MSTI 1 MSTI regional root : 32769.00:13:c3:9e:c8:80 Root cost : 22000 Root port : xe-10/2/0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Hop count : 18 Number of topology changes : 1 Time since last topology change : 1191 seconds Local parameters Bridge ID : 32769.00:90:69:0b:7f:d1 Extended system ID : 1 STP bridge parameters for MSTI 2 MSTI regional root : 32770.00:13:c3:9e:c8:80 Root cost : 22000 Root port : xe-10/2/0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Hop count : 18 Number of topology changes : 1 Time since last topology change : 1191 seconds Local parameters Bridge ID : 32770.00:90:69:0b:7f:d1 Extended system ID : 1
show spanning-tree bridge msti
user@host> show spanning-tree bridge msti 1 routing-instance vs1 detail
STP bridge parameters Routing instance name : vs1 Enabled protocol : MSTP STP bridge parameters for MSTI 1 MSTI regional root : 32769.00:13:c3:9e:c8:80 Root cost : 22000 Root port : xe-10/2/0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Hop count : 18 Number of topology changes : 1 Time since last topology change : 1191 seconds Local parameters Bridge ID : 32769.00:90:69:0b:7f:d1 Extended system ID : 1
show spanning-tree bridge vlan-id (MSTP)
user@host> show spanning-tree bridge vlan-id 1 101 routing-instance vs1 detail
STP bridge parameters Routing instance name : vs1 Enabled protocol : MSTP STP bridge parameters for CIST Root ID : 32768.00:13:c3:9e:c8:80 Root cost : 0 Root port : xe-10/2/0 CIST regional root : 32768.00:13:c3:9e:c8:80 CIST internal root cost : 22000 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Hop count : 18 Message age : 0 Number of topology changes : 0 Local parameters Bridge ID : 32768.00:90:69:0b:7f:d1 Extended system ID : 1 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Path cost method : 32 bit Maximum hop count : 20
show spanning-tree bridge (VSTP)
user@host> show spanning-tree bridge
STP bridge parameters Routing instance name : GLOBAL Enabled protocol : RSTP Root ID : 28672.00:90:69:0b:3f:d0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Message age : 0 Number of topology changes : 58 Time since last topology change : 14127 seconds Local parameters Bridge ID : 28672.00:90:69:0b:3f:d0 Extended system ID : 0 STP bridge parameters for bridge VLAN 10 Root ID : 28672.00:90:69:0b:3f:d0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Message age : 0 Number of topology changes : 58 Time since last topology change : 14127 seconds Local parameters Bridge ID : 28672.00:90:69:0b:3f:d0 Extended system ID : 0 STP bridge parameters for bridge VLAN 20 Root ID : 28672.00:90:69:0b:3f:d0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Message age : 0 Number of topology changes : 58 Time since last topology change : 14127 seconds Local parameters Bridge ID : 28672.00:90:69:0b:3f:d0 Extended system ID : 0
show spanning-tree bridge vlan-id (VSTP)
user@host> show spanning-tree bridge vlan-id 10
STP bridge parameters Routing instance name : GLOBAL Enabled protocol : RSTP STP bridge parameters for VLAN 10 Root ID : 28672.00:90:69:0b:3f:d0 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Message age : 0 Number of topology changes : 58 Time since last topology change : 14127 seconds Local parameters Bridge ID : 28672.00:90:69:0b:3f:d0 Extended system ID : 0
Published: 2010-07-13

Field Name	Field Description
Routing instance name	Name of the routing instance under which the bridge is configured.
Enabled protocol	Spanning Tree Protocol type enabled.
Root ID	Bridge ID of the elected spanning tree root bridge. The bridge ID consists of a configurable bridge priority and the MAC address of the bridge.
Root cost	Calculated cost to reach the root bridge from the bridge where the command is entered.
Root port	Interface that is the current elected root port for this bridge.
CIST regional root	Bridge ID of the elected MSTP regional root bridge.
CIST internal root cost	Calculated cost to reach the regional root bridge from the bridge where the command is entered.
Hello time	Configured number of seconds between transmissions of configuration bridge protocol data units (BPDUs).
Maximum age	Configured maximum expected arrival time of hello bridge protocol data units (BPDUs).
Forward delay	Configured time an STP bridge port remains in the listening and learning states before transitioning to the forwarding state.
Hop count	Configured maximum number of hops a BPDU can be forwarded in the MSTP region.
Message age	Number of elapsed seconds since the most recent BPDU was received.
Number of topology changes	Total number of STP topology changes detected since the routing device last booted.
Time since last topology change	Number of elapsed seconds since the most recent topology change.
Bridge ID (Local)	Locally configured bridge ID. The bridge ID consists of a configurable bridge priority and the MAC address of the bridge.
Extended system ID	System identifier.
MSTI regional root	Bridge ID of the elected MSTP regional root bridge.