Ubiquiti ES-24-250W, Administration Manual

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165
Configuring Switching Information EdgeSwitch
™
Administration Guide
Ubiquiti Networks, Inc.
Spanning Tree CST Port Fields (Continued)
Field Description
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.
Port Path Cost The path cost from the port to the root bridge.
Description A user-configured description of the port. If you select an interface and click Edit , the Edit CST Port
Entry dialog box (described below) opens and allows you to edit the CST port settings and view
additional CST information for the interface.
Edit CST Port Entry dialog box – When you click Edit , this dialog box opens and allows you to configure these additional fields:
Admin Edge Port Select this option to 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.
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 Select this option to enable this feature. 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 Flood Select this option to enable this feature, which determines the behavior of the interface if STP is
disabled on the port and the port receives a BPDU. If BPDU flooding is enabled, the port will flood the
received BPDU to all the ports on the switch that are similarly disabled for spanning tree.
BPDU Guard Effect Shows the status ( Disabled or Enabled ) 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 Used to Enable or Disable 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 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.
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.
Designated Bridge The bridge ID of the bridge with the designated port.
Designated Port The port ID of the designated port.