Dell POWEREDGE M1000E - Manual (Page 660)

660 Configuring the Spanning Tree Protocol
Configuring MSTP
This example shows how to configure IEEE 802.1s Multiple Spanning Tree
(MST) protocol on the switches shown in Figure 22-16.
Figure 22-16. MSTP Configuration Example
To make multiple switches be part of the same MSTP region, make sure the
STP operational mode for all switches is MSTP. Also, make sure the MST
region name and revision level are the same for all switches in the region.
To configure the switches:
1 Create VLAN 10 (Switch A and Switch B) and VLAN 20 (all switches).
console#configure
console(config)#vlan database
console(config-vlan)#vlan 10
console(config-vlan)#vlan 20
console(config-vlan)#exit
NOTE: Even Switch B does not have any ports that are members of VLAN 10,
this VLAN must be created to allow the formation of MST regions made up of
all bridges that exchange the same MST Configuration Identifier. It is only
within these MST Regions that multiple instances can exist.
Switch A
Switch B
Switch C
Port 1
Port 1
Port 2
VLAN 20 VLAN 10
VLAN 20
VLAN 10
VLAN 20
Port 2
Port 2
Port 1