Administrator Guide

Table 50. Default Values for Port Cost
Port Cost Default Value
1000-Mb/s Ethernet interfaces 20000
10-Gigabit Ethernet interfaces 2000
40-Gigabit Ethernet interfaces 1400
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
NOTE: The Dell Networking OS implementation of PVST+ uses IEEE 802.1s costs as the default costs.
Other implementations use IEEE 802.1w costs as the default costs. If you are using Dell Networking
systems in a multi-vendor network, verify that the costs are values you intended.
To change the port cost or port priority of an interface, use the following commands.
• Change the port cost of an interface.
INTERFACE mode
spanning-tree pvst vlan cost.
The range is from 0 to 200000.
Refer to the table for the default values.
• Change the port priority of an interface.
INTERFACE mode
spanning-tree pvst vlan priority.
The range is from 0 to 240, in increments of 16.
The default is 128.
The values for interface PVST+ parameters are given in the output of the show spanning-tree pvst
command, as previously shown.
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 only
implement
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.
Per-VLAN Spanning Tree Plus (PVST+) 716