Spanning Tree Cst Port Configuration - Ubiquiti EdgeSwitch ES-24-250W Administration Manual

EdgeSwitch Administration Guide
™

Spanning Tree CST Port Configuration

Use the CST Port page to view and configure the Common Spanning Tree (CST) settings for each interface on
the device. To configure CST settings for an interface and to view additional information about the interface's
role in the CST topology, select the interface to view or configure and click Edit.
To display the Spanning Tree CST Port page, click Switching > Spanning Tree > CST Port in the navigation menu.
Field
Interface
Port Role
Port Forwarding State
Ubiquiti Networks, Inc.
Spanning Tree CST Port
Spanning Tree CST Port Fields
Description
The port or link aggregation group (LAG) associated with the rest of the data in the row. When
configuring CST settings for an interface, this field identifies the interface being configured.
The role of the port within the CST, 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.
• 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 populate 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.
Configuring Switching Information
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