CLI Reference Guide-R02

Chapter 17 | Spanning Tree Commands
– 512 –
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆ When enabled, BPDUs are flooded to all other spanning-tree disabled ports on
the switch or within the receiving port's native VLAN as specified by the
spanning-tree system-bpdu-flooding command.
◆ The spanning-tree system-bpdu-flooding command has no effect if BPDU
flooding is disabled on a port by the spanning-tree port-bpdu-flooding
command.
Example
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree port-bpdu-flooding
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.
◆ The criteria used for determining the port role is based on root bridge ID, root
path cost, designated bridge, designated port, port priority, and port number,
in that order and as applicable to the role under question.