205
run in the MSTP mode by default, their bridge priority, port priority and port route cost are
all in the default values (equal). The default configuration for switches is listed below:
Bridge Name
SwitchA
SwitchB SwitchC SwitchD
Bridge MAC
Address
…00-00-01 …00-00-02 …00-00-03 …00-00-04
Bridge Priority
32768
32768
32768
32768
Port 1
128
128
128
Port 2
128
128
128
Port 3
128
128
Port 4
128
128
Port 5
128
128
Port 6
128
128
Port Priority
Port 7
128
128
Port 1
200000
200000
200000
Port 2
200000
200000
200000
Port 3
200000
200000
Port 4
200000
200000
Port 5
200000
200000
Port 6
200000
200000
Route Cost
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:
z
Create VLAN 20, 30, 40, 50 in SwitchB, SwitchC and SwitchD.
z
Set ports 1-7 as trunk ports in SwitchB, SwitchC and SwitchD.
Step 2: Set SwitchB, SwitchC and SwitchD in the same MSTP:
z
Set SwitchB, SwitchC and SwitchD to have the same region name as mstp.
z
Map VLAN 20 and VLAN 30 in SwitchB, SwitchC and SwitchD to Instance 3;
Map VLAN 40 and VLAN 50 in SwitchB, SwitchC and SwitchD to Instance 4.
Step 3: Set SwitchC as the root bridge of Instance 3; Set SwitchD as the root bridge of
Instance 4
z
Set the bridge priority of Instance 3 in SwitchC as 0.
z
Set the bridge priority of Instance 4 in SwitchD as 0.
The detailed configuration is listed below:
