show mstp

Displays the MSTP information.
Syntax
show mstp { [ detail ] mstp-id | configuration }
Parameters
detail
Displays detailed MSTP information for the specified ID.
mstp-id
Displays the MSTP information for a specific ID.
configuration
Displays MSTP configuration information.
Modes

User EXEC mode

Privileged EXEC mode

Global configuration mode

Interface configuration mode

VLAN configuration mode

The show mstp command displays the following information:

Output field Description
MSTP Instance The ID of the MSTP instance whose statistics are being displayed. For the CIST, this number is 0.
VLANs The number of VLANs that are included in this instance of MSTP. For the CIST, this number will always be 1.
Bridge Identifier The MAC address of the bridge.
Bridge MaxAge sec Displays the configured maximum age.
Bridge Hello sec Displays the configured Hello variable.
Bridge FwdDly sec Displays the configured FwdDly variable.
Bridge Hop cnt Displays the configured Max Hop count variable.
Root MaxAge sec The maximum age configured on the root bridge.
Root Hello sec Hello interval configured on the root bridge.
Root FwdDly sec FwdDly interval configured on the root bridge.
Root Hop Cnt Maximum hop count left from the root bridge.
Root Bridge Bridge identifier of the root bridge.
ExtPath Cost The configured path cost on a link connected to this port to an external MSTP region.
Regional Root Bridge The Regional Root Bridge is the MAC address of the root bridge for the local region.
IntPath Cost The configured path cost on a link connected to this port within the internal MSTP region.
Designated Bridge The MAC address of the bridge that sent the best BPDU that was received on this port.
Root Port Port indicating shortest path to root. Set to "Root" if this bridge is the root bridge.
Port Num The port number of the interface.
Pri The configured priority of the port. The default is 128.
PortPath Cost Configured or auto-detected path cost for port.
P2P Mac Indicates if the port is configured with a point-to-point link:
  • T - The port is configured in a point-to-point link.
  • F - The port is not configured in a point-to-point link.
Edge Indicates if the port is configured as an operational edge port:
  • T - Indicates that the port is defined as an edge port.
  • F - Indicates that the port is not defined as an edge port.
Role The port current spanning tree state. A port can have one of the following states:
  • Forwarding
  • Discarding
  • Learning
  • Disabled
Designated Cost Port path cost to the root bridge.
Max Hop cnt The maximum hop count configured for this instance.
Examples

The following example displays the MSTP information for a specified MSTP instance. 

device# show mstp 1
MSTP Instance 1 - VLANs: 2
----------------------------------------------------------------------------------
Bridge            Max          RegionalRoot       IntPath     Designated       Root    Root
Identifier        Hop          Bridge             Cost        Bridge           Port    Hop
hex               cnt          hex                            hex                      cnt
8001000cdb80af01  20           8001000cdb80af01   0           8001000cdb80af01  Root   20
Port    Pri       PortPath     Role State         Designa-    Designated
Num     Cost                                      ted cost    bridge
3/1 128 2000      MASTER       FORWARDING         0           8001000cdb80af01

The following example displays the detailed MSTP information. 

device# show mstp detail
MSTP Instance 0 (CIST) - VLANs: 4093
----------------------------------------------------------------------------
Bridge: 800000b000c00000 [Priority 32768, SysId 0, Mac 00b000c00000]
FwdDelay 15, HelloTime 2, MaxHops 20, TxHoldCount 6
Port 6/54 - Role: DESIGNATED - State: FORWARDING
PathCost 20000, Priority 128, OperEdge T, OperPt2PtMac F, Boundary T
Designated - Root 800000b000c00000, RegionalRoot 800000b000c00000,
Bridge 800000b000c00000, ExtCost 0, IntCost 0
ActiveTimers - helloWhen 1
MachineState - PRX-DISCARD, PTX-IDLE, PPM-SENDING_RSTP, PIM-CURRENT
PRT-ACTIVE_PORT, PST-FORWARDING, TCM-INACTIVE
BPDUs - Rcvd MST 0, RST 0, Config 0, TCN 0
Sent MST 6, RST 0, Config 0, TCN 0

The following example displays the MSTP configuration details. 

device# show mstp configuration
MSTP CONFIGURATION
------------------
Name : Reg1
Revision : 1
Version : 3 (MSTP mode)
Status : Started
Instanc  VLANs
-------- --------------
0        4093
Parent topic: Show Commands