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Configuration Commands
When configuring STP bridge parameters, the following formulas must be used:
•
•2*(hello+1) ≤ mxage
Spanning Tree port configuration
The default configuration for STP/PVST+ is off for downlink ports
Spanning tree port parameters are used to modify STP operation on an individual port basis. STP port parameters include:
•Port priority
•Port path cost
The following table describes the Spanning Tree Port Configuration commands.
Table 110 Spanning Tree Port Configuration commands
Command | Description |
|
|
Configures the port priority. The port priority helps determine which | |
priority | 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. |
| The range is 0 to 255, and the default is 128. |
| RSTP/MSTP: The range is 0 to 240, in steps of 16 (0, 16, 32...) and the |
| default is 128. |
| Command mode: Interface port |
|
|
Configures the port path cost. The port path cost is used to help | |
determine the designated port for a segment. Generally speaking, the | |
| faster the port, the lower the path cost. |
| The range is 1 to 65535. The default is 100 for 10Mb ports, 10 for 100 |
| Mb ports, 4 for Gigabit ports, and 2 for 10Gb ports. |
| A value of 0 indicates that the default cost will be computed for an auto- |
| negotiated link speed. |
| RSTP/MSTP: The range is 1 – 200000000, and the default it 20000 for |
| Gigabit ports, 2000 for 10Gb ports. |
| Command mode: Interface port |
|
|
Defines the type of link connected to the port, as follows: | |
link {autop2pshared} | • |
| |
| match its settings. |
| • |
| • |
| a hub). |
| This command only applies when RSTP is turned on. See the “Common |
| Internal Spanning Tree configuration” section for more information. |
| Command mode: Interface port |
|
|
| 136 |