MES53xx, MES33xx, MES23xx Ethernet Switch Series
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APPENDIX A. EXAMPLE OF DEVICE USAGE AND CONFIGURATION
Configuration of multiple spanning trees (MSTP)
MSTP is used to create multiple spanning trees for separate VLAN groups on the local network
switches, which allows you to balance load. For simplicity, let us consider the case with three switches
joined into a ring topology.
Let the VLAN 10, 20, 30 be joined in the first copy of MSTP and the VLAN 40, 50, 60 joined in the
second copy. It is required that the traffic of VLAN 10, 20, 30 is transferred directly between the first and
second switch, and the traffic of VLAN 40, 50, 60 is transmitted via transit through switch 3. Let's assign
switch 2 as the root one for the internal spanning tree (IST) where service information is transmitted. The
switches are joined into a ring using ports te1 and te2. Below you can find a diagram illustrating logic
topology of the network.
Figure 25. Configuration of the multiple spanning tree protocol
When one of the switches fails or the link is broken, multiple MSTP trees are rebuilt, which
mitigates the consequences of the failure. Below you can find the configuration processes for the
switches. For faster configuration, a common configuration template is created. This template is uploaded
to a TFTP server and later is used for configuration of all switches.
1.
Creating a template and configuring the 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 mst
console(config)#
interface range TengigabitEthernet
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
