HPE OfficeConnect 1920S 24G series, Management And Configuration Manual

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Page 56 Spanning Tree
Table 21. Spanning Tree MSTP Port Edit and Details Fields
Field Description
Interface 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.
Port Priority The priority for the port within the CST. This value is used in determining which port on a
switch becomes the root port when two ports have the same least-cost path to the root. The
port with the lower priority value becomes the root port. If the priority values are the same, the
port with the lower interface index becomes the root port.
Admin Edge Port Select this option administratively configure the interface as an edge port. An edge port is an
interface that is directly connected to a host and is not at risk of causing a loop.
Port Path Cost The path cost from the port to the root bridge.
Auto-calculate Port Path
Cost
Shows whether the path cost from the port to the root bridge is automatically determined by
the speed of the interface (Enabled) or configured manually (Disabled).
Hello Timer The amount of time the port waits between sending hello BPDUs.
External Port Path Cost The cost of the path from the port to the CIST root. This value becomes important when the
network includes multiple regions.
Auto-calculate External
Port Path Cost
Shows whether the path cost from the port to the CIST root is automatically determined by
the speed of the interface (Enabled) or configured manually (Disabled).
BPDU Filter When enabled, this feature filters the BPDU traffic on the edge ports. Edge ports do not need
to participate in the spanning tree, so BPDU filtering allows BPDU packets received on edge
ports to be dropped.
BPDU Guard Effect Shows the status of BPDU Guard Effect on the interface. When enabled, BPDU Guard Effect
can disable edge ports that receive BPDU packets. This prevents a new device from entering
the existing STP topology. Thus devices that were originally not a part of STP are not allowed
to influence the STP topology.
Port ID A unique value that is automatically generated based on the port priority value and the
interface index.
Port Up Time Since
Counters Last Cleared
The amount of time that the port has been up since the counters were cleared.
Port Mode The administrative mode of spanning tree on the port.
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.
Port Role 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.
Designated Root The bridge ID of the root bridge for the CST.
Designated Cost The path cost offered to the LAN by the designated port.