Alcatel Carrier Internetworking Solutions Switch/Router ユーザーズマニュアル

Page 17-36

The 

 command allows you to view the current Fast Spanning Tree port parameters on a 

selected group or 

VLAN

. To view the port parameters, enter the 

 command as shown:

where 

 is the number of the group in the switch for which you want to view 

Fast Spanning Tree port parameters. For example, to view parameters for Group 1, enter:

If Fast Spanning Tree is not enabled (default), a screen similar to the following will appear:

As a variation on this command, you can enter 

at the system prompt without specifying 

a group number. This will allow you to view the port parameters on the currently selected 
group. For information on how to select a group, see Selecting a Default Group on page 17-7.

The fields displayed by the 

 command include.

. The slot and interface (port) number of the port.

. The service type and instance of the service connected to the port.

 The port's current state as defined by application of the fast spanning tree protocol. 

This state controls what action a port takes on reception of a frame. The 

 values include:

Disabled - The port has been disabled.

Blocking - The port is not participating in transmitting data in order to 
prevent loops.

Listening - The port is preparing to transmit data, but is temporarily 
disabled in order to prevent loops. 

BPDU

 processing does occur, but no 

user data is being passed.

Learning - The port is preparing to transmit data, adding source 

MAC

 

addresses to the bridging table, but incoming data frames are dropped. 

Forwarding - The port is transmitting data. This state applies to Root 
Ports and Designated Ports.

Forwards - The port is transmitting data. This state applies to Designated 
Ports, and monitors old root ports for a period equivalent to two times 
the Forward Delay Timer default time period (default = 15 seconds).

Forwarder - The port is transmitting data. This state applies to 
Designated Ports, and monitors old root ports for a period equivalent to 
the Forward Delay Timer default time period (default = 15 seconds). 

Forgetting - The port is discarding frames, and is not learning source 
addresses. This state applies to prior Designated Ports that are placed 
into an Alternate Role. Forgetting State minimizes potential denial of 
service due to information races during extensive reconfigurations.