Configuring Spanning Tree Protocol (STP)

 

 

Table 5.3: CLI Display of STP Information (Continued)

 

 

 

 

 

 

This Field...

 

Displays...

 

 

 

 

 

 

State

 

The port’s STP state. 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 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 bridge(s) 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’s 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.

 

 

 

 

 

 

Fwd Trans

 

The number of times STP has changed the state of this port between

 

 

 

BLOCKING and FORWARDING.

 

 

 

 

 

 

Design Cost

 

The cost to the root bridge as advertised by the designated bridge that

 

 

 

is connected to this port. If the designated bridge is the root bridge

 

 

 

itself, then the cost is 0. The identity of the designated bridge is

 

 

 

shown in the Design Bridge field.

 

 

 

 

 

 

Design Root

 

The root bridge as recognized on this port. The value is the same as

 

 

 

the root bridge ID listed in the Root ID field.

 

 

 

 

 

 

Design Bridge

 

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.

 

 

 

 

 

USING THE WEB MANAGEMENT INTERFACE

To display STP information:

1.Log on to the device using a valid user name and password for read-only or read-write access. The System configuration panel is displayed.

2.Click on the plus sign next to Monitor in the tree view to display the monitoring options.

3.Select the STP link to display the STP bridge and port parameters.

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