DELL PC6224F User Manual

Spanning Tree Commands

Use the spanning-tree mode command in Global Configuration mode to 

configure the spanning-tree protocol. To return to the default configuration, 

use the no form of this command.

spanning-tree mode {stp | rstp |mstp}
no spanning-tree mode

• stp — Spanning Tree Protocol (STP) is enabled.
• rstp — Rapid Spanning Tree Protocol (RSTP) is enabled.
•

mstp — Multiple Spanning Tree Protocol (MSTP) is enabled.

Rapid Spanning Tree Protocol (RSTP) is supported.

Global Configuration mode

In RSTP mode the switch would use STP when the neighbor switch is using 

STP. In MSTP mode the switch would use RSTP when the neighbor switch is 

using RSTP and would use STP when the neighbor switch is using STP.

The following example configures the spanning-tree protocol to MSTP.

console(config)#spanning-tree mode mstp

Use the spanning-tree mst 0 external-cost command to set the external cost 

for the common spanning tree. The external cost is used by the switch when 

negotiating spanning tree topology outside the region. 

  Since by default each switch is in its own region, the external cost is considered in 

determining the spanning tree in the network.