Spanning Tree
49
Spanning Tree MSTP Port Summary
To display the Spanning Tree MSTP Port Summary page, click
Switching
>
Spanning Tree
in the
navigation pane, and then click the
MSTP Port
tab.
Figure 27. Spanning Tree MSTP Port Summary Page
Table 17. Spanning Tree MSTP Port Summary Fields
Field
Description
MSTP ID
The menu contains the ID of each MST instance that has been created on the device.
Interface
The port or link aggregation group (LAG) associated with the rest of the data in the row. When
configuring MST settings for an interface, this field identifies the interface being configured.
Port Role
The role of the port within the MST, which is one of the following:
Root – A port on the non-root bridge that has the least-cost path to the root bridge.
Designated – A port that has the least-cost path to the root bridge on its segment.
Alternate – A blocked port that has an alternate path to the root bridge.
Backup – A blocked port that has a redundant path to the same network segment as
another port on the bridge.
Master – The port on a bridge within an MST instance that links the MST instance to
other STP regions.
Disabled – The port is administratively disabled and is not part of the spanning tree.
Port Forwarding State
Blocking – The port discards user traffic and receives, but does not send, BPDUs. During
the election process, all ports are in the blocking state. The port is blocked to prevent
network loops.
Listening – The port sends and receives BPDUs and evaluates information to provide a
loop-free topology. This state occurs during network convergence and is the first state in
transitioning to the forwarding state.
Learning – The port learns the MAC addresses of frames it receives and begins to popu-
late the MAC address table. This state occurs during network convergence and is the
second state in transitioning to the forwarding state.
Forwarding – The port sends and receives user traffic.
Disabled – The port is administratively disabled and is not part of the spanning tree.
