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MES1000, MES2000 Ethernet Switches
APPENDIX A SAMPLES OF USE AND CONFIGURATION OF DEVICE
Configuration of multiple spanning trees (MSTP)
MSTP Protocol allows to build multiple spanning trees for separate VLAN groups in switches of
local network which allows to balance load. For simplicity lets consider case with three switches joined
into ring topology.
Let the vlan 10, 20, 30 are joined in firts copy of MSTP, vlan 40, 50, 60 are joined in second copy. It
is required that traffic of VLANs 10, 20, 30 between first and second switches is transferred directly, and
traffic of VLANs 40, 50, 60 is transferred through transit via switch 3. Lets assign switch 2 as root one for
internal spanning tree (IST – Internal Spanning Tree) where service information is transferred to. Switches
are joined into ring using ports g1 and g2. Below you can find digram illustrating logic topology of the
network.
Figure 27 - Configuration of protocol of multiple spanning trees
When one of switches is fault or the channel is broken, multiple trees MSTP are rebuild which
allows minimizing consequences of the fault. Below you can find switches configuration process. For faster
configuration common configuration template is created, this template is uploaded to TFTP server and
later is used for configuration of all switches.
1.
Creation of the template and configuration of first switch
console# configure
console(config)# vlan database
console(config-vlan)# vlan 10,20,30,40,50,60
console(config-vlan)# exit
console(config)# interface vlan 1
console(config-if)# ip address 192.168.16.1 /24
console(config-if)# exit
console(config)# spanning-tree mode mstp
console(config)# interface range gigabitethernet 1/0/1-2
console(config-if)# switchport mode trunk
console(config-if)# switchport trunk allowed vlan add 10,20,30,40,50,60
console(config-if)# exit
console(config)# spanning-tree mst configuration
console(config-mst)# name sandbox
console(config-mst)# instance 1 add vlan 10,20,30
console(config-mst)# instance 2 add vlan 40,50,60
console(config-mst)# exit
