25. Spanning Tree
ROX™ v2.2 User Guide
257
RuggedBackbone™ RX5000
The role of this port in the spanning tree:
• Designated : The port is designated for (i.e. carries traffic towards the root for) the LAN it is
connected to.
• Root : The single port on the bridge, which provides connectivity towards the root bridge.
• Backup : The port is attached to a LAN that is serviced by another port on the bridge. It is not
used but is standing by.
• Alternate : The port is attached to a bridge that provides connectivity to the root bridge. It is not
used but is standing by.
• Master : Only exists in MSTP. The port is an MST region boundary port and the single port on the
bridge, which provides connectivity for the Multiple Spanning Tree Instance towards the Common
Spanning Tree root bridge (i.e. this port is the root port for the Common Spanning Tree Instance).
STP Cost
Synopsis: unsigned integer
The cost offered by this port. If the Bridge RSTP Parameters Cost Style is set to STP, 1Gbps ports
will contribute a cost of four, 100 Mbps ports will contribute 19 and 10 Mbps ports contribute 100. If
the Cost Style is set to RSTP, 1Gbps will contribute 20,000, 100 Mbps ports will contribute a cost
of 200,000 and 10 Mbps ports contribute a cost of 2,000,000. Note that even if the Cost style is set
to RSTP, a port that migrates to STP will have its cost limited to a maximum of 65535.
Desig Bridge Priority
Synopsis: integer
Provided on the root ports of the designated bridges, the Bridge Identifier of the bridge this port
is connected to.
Desig Bridge MAC
Synopsis: Ethernet MAC address in colon-separated hexadecimal notation
Provided on the root ports of designated bridges, the Bridge Identifier of the bridge this port is
connected to.
Oper Edge
Synopsis: boolean
Whether or not the port is operating as an edge port.
RX RSTs
Synopsis: unsigned integer
The count of RSTP configuration messages received on this port.
TX RSTs
Synopsis: unsigned integer
The count of RSTP configuration messages transmitted on this port.
RX Configs
Synopsis: unsigned integer
The count of STP configuration messages received on this port.
TX Configs
Synopsis: unsigned integer
The count of STP configuration messages transmitted on this port.
RX Tcns
Synopsis: unsigned integer
The count of configuration change notification messages received on this port. Excessively high or
rapidly increasing counts signal network problems.