This command displays the detailed settings and parameters for a specific switch port within a particular multiple spanning tree instance. The parameter mstid is a number that corresponds to the desired existing multiple spanning tree instance. The unit/slot/port is the desired switch port. Instead of unit/slot/port, lag lag-intf-num can be used as an alternate way to specify the LAG (Link Aggregation Group) interface. lag lag-intf-num can also be used to specify the LAG interface where lag-intf-num is the LAG port number.
| Format | show spanning-tree mst port detailed mstid unit/slot/port|lag lag-intf-num |
| Mode |
|
| MST Instance ID | The ID of the existing multiple spanning tree (MST) instance identifier. The value is 0–4094. |
| Port Identifier | The port identifier for the specified port within the selected MST instance. It is made up from the port priority and the interface number of the port. |
| Port Priority | The priority for a particular port within the selected MST instance. The port priority is displayed in multiples of 16. |
| Port Forwarding State | Current spanning tree state of this port. |
| Port Role | Each enabled MST Bridge Port receives a Port Role for each spanning tree. The port role is one of the following values: Root Port, Designated Port, Alternate Port, Backup Port, Master Port or Disabled Port |
| Auto-Calculate Port Path Cost | Whether auto calculation for port path cost is enabled. |
| Port Path Cost | Configured value of the Internal Port Path Cost parameter. |
| Designated Root | The Identifier of the designated root for this port. |
| Root Path Cost | The path cost to get to the root bridge for this instance. The root path cost is zero if the bridge is the root bridge for that instance. |
| Designated Bridge | Bridge Identifier of the bridge with the Designated Port. |
| Designated Port Identifier | Port on the Designated Bridge that offers the lowest cost to the LAN. |
| Loop Inconsistent State | The current loop inconsistent state of this port in this MST instance. When in loop inconsistent state, the port has failed to receive BPDUs while configured with loop guard enabled. Loop inconsistent state maintains the port in a blocking state until a subsequent BPDU is received. |
| Transitions Into Loop Inconsistent State | The number of times this interface has transitioned into loop inconsistent state. |
| Transitions Out of Loop Inconsistent State | The number of times this interface has transitioned out of loop inconsistent state. |
If you specify 0 (defined as the default CIST ID) as the mstid, this command displays the settings and parameters for a specific switch port within the common and internal spanning tree. The unit/slot/port is the desired switch port. In this case, the following are displayed.
| Port Identifier | The port identifier for this port within the CST. |
| Port Priority | The priority of the port within the CST. |
| Port Forwarding State | The forwarding state of the port within the CST. |
| Port Role | The role of the specified interface within the CST. |
| Auto-Calculate Port Path Cost | Whether auto calculation for port path cost is enabled or not (disabled). |
| Port Path Cost | The configured path cost for the specified interface. |
| Auto-Calculate External Port Path Cost | Whether auto calculation for external port path cost is enabled. |
| External Port Path Cost | The cost to get to the root bridge of the CIST across the boundary of the region. This means that if the port is a boundary port for an MSTP (Multiple Spanning Tree Protocol) region, then the external path cost is used. |
| Designated Root | Identifier of the designated root for this port within the CST. |
| Root Path Cost | The root path cost to the LAN by the port. |
| Designated Bridge | The bridge containing the designated port. |
| Designated Port Identifier | Port on the Designated Bridge that offers the lowest cost to the LAN. |
| Topology Change Acknowledgment | Value of flag in next Configuration Bridge Protocol Data Unit (BPDU) transmission indicating if a topology change is in progress for this port. |
| Hello Time | The hello time in use for this port. |
| Edge Port | The configured value indicating if this port is an edge port. |
| Edge Port Status | The derived value of the edge port status. True if operating as an edge port; false otherwise. |
| Point To Point MAC Status | Derived value indicating if this port is part of a point to point link. |
| CST Regional Root | The regional root identifier in use for this port. |
| CST Internal Root Path Cost | The internal root path cost to the LAN by the designated external port. |
| Loop Inconsistent State | The current loop inconsistent state of this port in this MST instance. When in loop inconsistent state, the port has failed to receive BPDUs while configured with loop guard enabled. Loop inconsistent state maintains the port in a blocking state until a subsequent BPDU is received. |
| Transitions Into Loop Inconsistent State | The number of times this interface has transitioned into loop inconsistent state. |
| Transitions Out of Loop Inconsistent State | The number of times this interface has transitioned out of loop inconsistent state. |
The following example shows CLI display output for the command in slot/port format.
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Download EPUB(Extreme 220) (Routing) #show spanning-tree mst port detailed 0 0/1
Port Identifier................................ 80:01
Port Priority.................................. 128
Port Forwarding State.......................... Disabled
Port Role...................................... Disabled
Auto-calculate Port Path Cost.................. Enabled
Port Path Cost................................. 0
Auto-Calculate External Port Path Cost......... Enabled
External Port Path Cost........................ 0
Designated Root................................ 80:00:00:10:18:48:FC:07
Root Path Cost................................. 0
Designated Bridge.............................. 80:00:00:10:18:48:FC:07
Designated Port Identifier..................... 00:00
Topology Change Acknowledge.................... FALSE
Hello Time..................................... 2
Edge Port...................................... FALSE
Edge Port Status............................... FALSE
Point to Point MAC Status...................... TRUE
CST Regional Root.............................. 80:00:00:10:18:48:FC:07
CST Internal Root Path Cost.................... 0
Loop Inconsistent State........................ FALSE
Transitions Into Loop Inconsistent State....... 0
Transitions Out Of Loop Inconsistent State..... 0
The following example shows CLI display output for the command using a LAG interface number.
(Extreme 220) (Routing) #show spanning-tree mst port detailed 0 lag 1 Port Identifier................................ 60:42 Port Priority.................................. 96 Port Forwarding State.......................... Disabled Port Role...................................... Disabled Auto-calculate Port Path Cost.................. Enabled Port Path Cost................................. 0 Auto-Calculate External Port Path Cost......... Enabled External Port Path Cost........................ 0 Designated Root................................ 80:00:00:10:18:48:FC:07 Root Path Cost................................. 0 Designated Bridge.............................. 80:00:00:10:18:48:FC:07 Designated Port Identifier..................... 00:00 Topology Change Acknowledge.................... FALSE Hello Time..................................... 2 Edge Port...................................... FALSE Edge Port Status............................... FALSE Point to Point MAC Status...................... TRUE CST Regional Root.............................. 80:00:00:10:18:48:FC:07 CST Internal Root Path Cost.................... 0 Loop Inconsistent State........................ FALSE Transitions Into Loop Inconsistent State....... 0 Transitions Out Of Loop Inconsistent State..... 0 --More-- or (q)uit (Extreme 220) (Routing) #