SMC Networks SMC8150L2 manual Spanning-tree port-priority

Spanning Tree Commands 4

•Fast Ethernet – half duplex: 200,000; full duplex: 100,000; trunk: 50,000

•Gigabit Ethernet – full duplex: 10,000; trunk: 5,000

•10 Gigabit Ethernet – full duplex: 1000; trunk: 500

Command Mode

Interface Configuration (Ethernet, Port Channel)

Command Usage

•This command is used by the Spanning Tree Algorithm to determine the best path between devices. Therefore, lower values should be assigned to ports attached to faster media, and higher values assigned to ports with slower media.

•Path cost takes precedence over port priority.

•When the spanning-tree pathcost method (page 4-149)is set to short, the maximum value for path cost is 65,535.

Example

Console(config)#interface ethernet 1/5

Console(config-if)#spanning-tree cost 50

Console(config-if)#

spanning-tree port-priority

This command configures the priority for the specified interface. Use the no form to restore the default.

Syntax

spanning-tree port-priority priority no spanning-tree port-priority

priority - The priority for a port. (Range: 0-240, in steps of 16)

Default Setting

128

Command Mode

Interface Configuration (Ethernet, Port Channel)

Command Usage

•This command defines the priority for the use of a port in the Spanning Tree Algorithm. If the path cost for all ports on a switch are the same, the port with the highest priority (that is, lowest value) will be configured as an active link in the spanning tree.

•Where more than one port is assigned the highest priority, the port with lowest numeric identifier will be enabled.

Example

Console(config)#interface ethernet 1/5

Console(config-if)#spanning-tree port-priority 0

4-155