Users Guide

Port Cost Default Value
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.
• Enable EdgePort on an interface.
INTERFACE mode
spanning-tree mstp edge-port [bpduguard | shutdown-on-violation]
Dell Networking OS Behavior: Regarding bpduguard shutdown-on-violation behavior:
• If the interface to be shut down is a port channel, all the member ports are disabled in the hardware.
• When you add a physical port to a port channel already in the Error Disable state, the new member
port is also disabled in the hardware.
Multiple Spanning Tree Protocol (MSTP) 598