N8406-023 1Gb Intelligent L3 Switch Command Reference Guide (ISCLI) 33
The following table describes the STP parameters in RSTP or MSTP mode.
Table 23 Rapid Spanning Tree parameter descriptions
Parameter
Description
Current Root
Shows information about the root bridge for the Spanning Tree. Information includes the
priority (hex) and MAC address of the root.
Path-Cost
Path-cost is the total path cost to the root bridge. It is the summation of the path cost
between bridges (up to the root bridge).
Port
The current root port refers to the port on the switch that receives data from the current
root. Zero (0) indicates the root bridge of the STP.
Priority (bridge)
The bridge priority parameter controls which bridge on the network will become the STP
root bridge.
Hello
The hello time parameter specifies, in seconds, how often the root bridge transmits a
configurationbridge protocol data unit (BPDU). Any bridge that is not the root bridge uses
the root bridge hello value.
MaxAge
The maximum age parameter specifies, in seconds, the maximum time the bridge waits
without receiving a configuration bridge protocol data unit before it reconfigures the STP
network. If the bridge is not the root bridge, it uses the
MaxAge
value of the root bridge.
FwdDel
The forward delay parameter specifies, in seconds, the amount of time that a bridge port
has to wait before it changes from learning state to forwarding state. If the bridge is not
the root bridge, it uses the
FwdDel
value of the root bridge.
Aging
The aging time parameter specifies, in seconds, the amount of time the bridge waits
without receiving a packet from a station before removing the station from the
Forwarding Database.
Priority (port)
The port priority parameter helps determine which bridge port becomes the designated
port. In a network topology that has multiple bridge ports connected to a single segment,
the port with the lowest port priority becomes the designated port for the segment.
Cost
The port path cost parameter is used to help determine the designated port for a
segment. Generally speaking, the faster the port, the lower the path cost. A setting of
zero (0) indicates that the cost will be set to the appropriate default after the link speed
has been auto-negotiated.
State
Shows the current state of the port. The State field in RSTP/MSTP mode can be one of
the following:
Discarding (DISC), Learning (LRN)
,
Forwarding (FWD)
, or
Disabled (DSB)
.
Role
Shows the current role of this port in the Spanning Tree. The port role can be one of the
following: Designated (DESG), Root (ROOT), Alternate (ALTN), Backup (BKUP), Master
(MAST), or Unknown (UNK).
Designated bridge
Shows information about the bridge connected to each port, if applicable. Information
includes the priority (hex) and MAC address of the Designated Bridge.
Designated port
The port ID of the port on the Designated Bridge to which this port is connected.
Type
Type of link connected to the port, and whether the port is an edge port. Link type values
are AUTO, P2P, or SHARED.
