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.