Information Menu 40
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
configuration bridge 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.
MSTP: The Type field appears in /info/cist.
