Allied Telesis AT-S63 - Manual (Page 448)

Chapter 25: Spanning Tree Protocol Commands
448 Section V: Spanning Tree Protocols
The root bridge parameter specifies the bridge identifier of the root bridge
of the spanning tree domain. The identifier consists of the bridge priority
value and MAC address of the root switch, separated by a slash (/). This
parameter only appears when STP is activated on the switch.
The root path cost parameter displays the path cost from the switch to the
root bridge of the spanning tree domain. If the switch is the root bridge, the
path cost is 0. This parameter only appears when STP is activated on the
switch.
The PORT parameter allows you to view the STP parameter settings for
the switch ports: An example of the display is shown in Figure 39.
Figure 39. SHOW STP PORT Command
Port is the port number.
State is the current state of a port. The possible states are Listening,
Learning, Forwarding, or Blocking when spanning tree is enabled on the
switch. When spanning tree is not enabled on the switch or if a port is not
being used, its state will be disabled.
Cost is the port cost of the port.
Priority is the port’s priority value. The number is used as a tie breaker
when two or more ports have equal costs to the root bridge.
Examples
The following command displays the switch’s STP settings:
show stp
The following command displays the STP settings for ports 1 to 4:
show stp port=1-4
Port State Cost Priority
----------------------------------------------
1
Forwarding 4 128
2 Forwarding 4 128
3 Forwarding 4 128
4 Forwarding 4 128
5 Forwarding 4 128
6 Forwarding 4 128
7 Forwarding 4 128
8 Forwarding 4 128
9 Forwarding 4 128
10 Forwarding 4 128
11 Forwarding 4 128