Users Guide

Table 60. Default Values for Port Costs by Interface
Port Cost Default Value
100-Mb/s Ethernet interfaces 200000
1-Gigabit Ethernet interfaces 20000
10-Gigabit Ethernet interfaces 2000
25-Gigabit Ethernet interfaces 1700
40-Gigabit Ethernet interfaces 1400
50-Gigabit Ethernet interfaces 1200
100-Gigabit Ethernet interfaces 200
Port Channel with 100 Mb/s Ethernet interfaces 180000
Port Channel with 1-Gigabit Ethernet interfaces 18000
Port Channel with 10-Gigabit Ethernet interfaces 1800
Port Channel with 25-Gigabit Ethernet interfaces 1200
Port Channel with 50-Gigabit Ethernet interfaces 200
Port Channel with 100-Gigabit Ethernet interfaces 180
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.
CAUTION
: Configure EdgePort only on links connecting to an end station. EdgePort can cause loops if you enable it on
an interface connected to a network.
To enable EdgePort on an interface, use the following command.
Multiple Spanning Tree Protocol (MSTP) 536