Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 264)

CLI display of detailed STP information for ports (Continued) TABLE 47
Field Description
Port number and
STP state The internal port number and the port STP state.
The internal port number is one of the following:
• The port interface number, if the port is the designated port for the LAN.
• The interface number of the designated port from the received BPDU, if the interface is not
the designated port for the LAN.
The state can be one of the following:
• BLOCKING - STP has blocked Layer 2 traffic on this port to prevent a loop. The device or
VLAN can reach the root bridge using another port, whose state is FORWARDING. When
a port is in this state, the port does not transmit or receive user frames, but the port does
continue to receive STP BPDUs.
• DISABLED - The port is not participating in STP. This can occur when the port is
disconnected or STP is administratively disabled on the port.
• FORWARDING - STP is allowing the port to send and receive frames.
• LISTENING - STP is responding to a topology change and this port is listening for a BPDU
from neighboring bridges in order to determine the new topology. No user frames are
transmitted or received during this state.
• LEARNING - The port has passed through the LISTENING state and will change to the
BLOCKING or FORWARDING state, depending on the results of STP reconvergence. The
port does not transmit or receive user frames during this state. However, the device can
learn the MAC addresses of frames that the port receives during this state and make
corresponding entries in the MAC table.
NOTE
If the state is DISABLED, no further STP information is displayed for the port.
Port Path cost The STP path cost for the port.
Port Priority This STP priority for the port. The value is shown as a hexadecimal number.
Root The ID assigned by STP to the root bridge for this spanning tree.
Designated Bridge The MAC address of the designated bridge to which this port is connected. The designated
bridge is the device that connects the network segment on the port to the root bridge.
Designated Port The port number sent from the designated bridge.
Designated Path
Cost The cost to the root bridge as advertised by the designated bridge that is connected to this
port. If the bridge is the root bridge itself, then the cost is 0. The identity of the designated
bridge is shown in the Designated Bridge field.
Spanning Tree Protocol
264 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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