Spanning Tree

Role

Synopsis: { <empty string>, Root, Designated, Alternate, Backup, Master } Role of this port in Spanning Tree. This may be one of the following:

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).

Cost

Synopsis: 0 to 4294967295

Cost offered by this port. If the Bridge RSTP Parameters Cost Style is set to STP, 1Gbps ports will contribute 4, 100 Mbps ports will contribute 19 and 10 Mbps ports contribute a cost of 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 ID

Synopsis: $$ / ##-##-##-##-##-## where $$ is 0 to 65535, ## is 0 to FF

Provided on the root ports of designated bridges, the Bridge Identifier of the bridge this port is connected to.

RS400

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ROS™ v3.5

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RuggedCom RS400 manual Spanning Tree Role, Cost