Specifications

show spanning-tree
227
Item Meaning Displayed information
MAC Address MAC address MAC address for root bridge
Root Cost Root path cost Path cost value from the Switch to the root bridge
0 is displayed if the Switch is the root bridge.
Root Port Root port Displays the port number of the root port. If the root port
is a link aggregation port, the port list for the channel
group and the channel group number (ChGr) are
displayed.
A hyphen (-) is displayed if the Switch is the root bridge.
Port Information Displays information about the ports managed by Single Spanning Tree.
IF# Interface port number Number of the interface port whose information is to be
displayed
Up The port is in Up status. Indicates that the port is in Up status.
If link aggregation is used, this means that the channel
group is in Up status.
Down The port is in Down status. Indicates that the port is in Down status.
If link aggregation is used, this means that the channel
group is in Down status.
Status Port state If Mode is STP:
Blocking: Blocking
Listening: Listening
Learning: Learning
Forwarding: Indicates Forwarding status.
Disabled: Disabled
If Mode is Rapid STP:
Discarding: Discarding
Learning: Learning
Forwarding: Indicates Forwarding status.
Disabled: Disabled
This parameter becomes Disabled if the port is in the
Down status.
Role The role of the port Root: Root port
Designated: Designated port
Alternate: Alternate port
Backup: Backup port
If the port is in the Down status, a hyphen (-) is
displayed, because ports in this status are not included
in the topology calculations. These parameters are
commonly used when Mode is STP or Rapid STP.
PortFast PortFast Indicates that the port is a PortFast port.
PortFast(BPDU
Guard)
PortFast (BPDU guard
functionality is applied)
Indicates that the port is a PortFast port, and that the
BPDU guard functionality is applied.
BPDU Filter BPDU filter Indicates that the BPDU filter functionality is applied.
LoopGuard Loop guard Indicates that the port applies the loop guard
functionality.