122
Displaying and maintaining the spanning tree
Execute
display
commands in any view and
reset
command in user view.
Task Command
Display information about ports blocked by spanning tree
protection functions.
display stp abnormal-port
Display BPDU statistics on ports.
display stp bpdu-statistics
[
interface
interface-type interface-number
[
instance
instance-list
] ]
Display information about ports shut down by spanning
tree protection functions.
display stp down-port
Display the historical information of port role calculation
for the specified MSTI or all MSTIs.
display stp
[
instance
instance-list
|
vlan
vlan-id-list
]
history
[
slot
slot-number
]
Display the statistics of TC/TCN BPDUs sent and received
by all ports in the specified MSTI or all MSTIs.
display stp
[
instance
instance-list
|
vlan
vlan-id-list
]
tc
[
slot
slot-number
]
Display the spanning tree status and statistics.
display stp
[
instance
instance-list
|
vlan
vlan-id-list
]
[
interface
interface-list
|
slot
slot-number
]
[
brief
]
Display the MST region configuration information that has
taken effect.
display stp region-configuration
Display the root bridge information of all MSTIs.
display stp root
Clear the spanning tree statistics.
reset stp
[
interface
interface-list
]
Spanning tree configuration example
Network requirements
As shown in
, all devices on the network are in the same MST region. Device A and Device B
work at the distribution layer. Device C and Device D work at the access layer.
Configure MSTP so that packets of different VLANs are forwarded along different spanning trees:
•
VLAN 10 packets are forwarded along MSTI 1.
•
VLAN 30 packets are forwarded along MSTI 3.
•
VLAN 40 packets are forwarded along MSTI 4.
•
VLAN 20 packets are forwarded along MSTI 0.
VLAN 10 and VLAN 30 are terminated on the distribution layer devices, and VLAN 40 is terminated on
the access layer devices. The root bridges of MSTI 1 and MSTI 3 are Device A and Device B, respectively,
and the root bridge of MSTI 4 is Device C.