Administrator Guide

The following lists the default values for port cost by interface.
Table 46. Default Values for Port Costs by Interface
Port Cost Default Value
1000-Mb/s Ethernet interfaces 20000
40-Gigabit Ethernet interfaces 1400
10-Gigabit Ethernet interfaces 2000
Port Channel with one 10–Gigabit Ethernet interface 2000
Port Channel with one 40-Gigabit Ethernet interface 1400
Port Channel with two 10-Gigabit Ethernet interfaces 1800
Port Channel with two 40-Gigabit Ethernet
interfaces
600
To change the port cost or priority of an interface, use the following commands.
1 Change the port cost of an interface.
INTERFACE mode
spanning-tree msti number cost cost
The range is from 0 to 200000.
For the default, refer to the default values shown in the table.
2 Change the port priority of an interface.
INTERFACE mode
spanning-tree msti number priority priority
The range is from 0 to 240, in increments of 16.
The default is 128.
To view the current values for these interface parameters, use the show config command from INTERFACE
mode.
Configuring an EdgePort
The EdgePort feature enables interfaces to begin forwarding traffic approximately 30 seconds sooner.
In this mode, an interface forwards frames by default until it receives a BPDU that indicates that it should
behave otherwise; it does not go through the Learning and Listening states. The bpduguard shutdown-on-
violation
option causes the interface hardware to be shut down when it receives a BPDU. When you
implement only bpduguard, although the interface is placed in an Error Disabled state when receiving the
BPDU, the physical interface remains up and spanning-tree drops packets in the hardware after a BPDU
violation. BPDUs are dropped in the software after receiving the BPDU violation. This feature is the same as
PortFast mode in spanning tree.
Multiple Spanning Tree Protocol (MSTP) 612