105
[DeviceD] stp enable
6.
Verify the configurations:
In this example, suppose that Device B has the lowest root bridge ID. As a result, Device B is
elected as the root bridge in MSTI 0.
You can use the
display stp brief
command to display brief spanning tree information on each
device after the network is stable.
# Display brief spanning tree information on Device A.
[DeviceA] display stp brief
MSTID Port Role STP State Protection
0 Ethernet1/0/1 ALTE DISCARDING NONE
0 Ethernet1/0/2 DESI FORWARDING NONE
0 Ethernet1/0/3 ROOT FORWARDING NONE
1 Ethernet1/0/1 DESI FORWARDING NONE
1 Ethernet1/0/3 DESI FORWARDING NONE
3 Ethernet1/0/2 DESI FORWARDING NONE
3 Ethernet1/0/3 ROOT FORWARDING NONE
# Display brief spanning tree information on Device B.
[DeviceB] display stp brief
MSTID Port Role STP State Protection
0 Ethernet1/0/1 DESI FORWARDING NONE
0 Ethernet1/0/2 DESI FORWARDING NONE
0 Ethernet1/0/3 DESI FORWARDING NONE
1 Ethernet1/0/2 DESI FORWARDING NONE
1 Ethernet1/0/3 ROOT FORWARDING NONE
3 Ethernet1/0/1 DESI FORWARDING NONE
3 Ethernet1/0/3 DESI FORWARDING NONE
# Display brief spanning tree information on Device C.
[DeviceC] display stp brief
MSTID Port Role STP State Protection
0 Ethernet1/0/1 DESI FORWARDING NONE
0 Ethernet1/0/2 ROOT FORWARDING NONE
0 Ethernet1/0/3 DESI FORWARDING NONE
1 Ethernet1/0/1 ROOT FORWARDING NONE
1 Ethernet1/0/2 ALTE DISCARDING NONE
4 Ethernet1/0/3 DESI FORWARDING NONE
# Display brief spanning tree information on Device D.
[DeviceD] display stp brief
MSTID Port Role STP State Protection
0 Ethernet1/0/1 ROOT FORWARDING NONE
0 Ethernet1/0/2 ALTE DISCARDING NONE
0 Ethernet1/0/3 ALTE DISCARDING NONE
3 Ethernet1/0/1 ROOT FORWARDING NONE
3 Ethernet1/0/2 ALTE DISCARDING NONE
4 Ethernet1/0/3 ROOT FORWARDING NONE
Based on the output, you can draw the MSTI mapped to each VLAN, as shown in
.