Planet XGS3-24042 - Page 160

17-8
Port 4
200000
200000
Port 5
200000
200000
Port 6
200000
200000
Port 7
200000
200000
By default, the MSTP establishes a tree topology (in blue lines) rooted with SwitchA. The ports marked with
“x” are in the discarding status, and the other ports are in the forwarding status.
Configurations Steps:
Step 1: Configure port to VLAN mapping:
 Create VLAN 20, 30, 40, 50 in Switch2, Switch3 and Switch4.
 Set ports 1-7 as trunk ports in Switch2 Switch3 and Switch4.
Step 2: Set Switch2, Switch3 and Switch4 in the same MSTP:
 Set Switch2, Switch3 and Switch4 to have the same region name as mstp.
 Map VLAN 20 and VLAN 30 in Switch2, Switch3 and Switch4 to Instance 3; Map VLAN 40 and VLAN
50 in Switch2, Switch3 and Switch4 to Instance 4.
Step 3: Set Switch3 as the root bridge of Instance 3; Set Switch4 as the root bridge of Instance 4
 Set the bridge priority of Instance 3 in Switch3 as 0.
 Set the bridge priority of Instance 4 in Switch4 as 0.
The detailed configuration is listed below:
Switch2:
Switch2(config)#vlan 20
Switch2(Config-Vlan20)#exit
Switch2(config)#vlan 30
Switch2(Config-Vlan30)#exit
Switch2(config)#vlan 40
Switch2(Config-Vlan40)#exit
Switch2(config)#vlan 50
Switch2(Config-Vlan50)#exit
Switch2(config)#spanning-tree mst configuration
Switch2(Config-Mstp-Region)#name mstp
Switch2(Config-Mstp-Region)#instance 3 vlan 20;30
Switch2(Config-Mstp-Region)#instance 4 vlan 40;50
Switch2(Config-Mstp-Region)#exit
Switch2(config)#interface e1/0/1-7
Switch2(Config-Port-Range)#switchport mode trunk
Switch2(Config-Port-Range)#exit
Switch2(config)#spanning-tree
Switch3:
Switch3(config)#vlan 20
Switch3(Config-Vlan20)#exit
Switch3(config)#vlan 30