Displaying And Maintaining The Spanning Tree - H3C SR8800 Configuration Manual

NOTE:
Do not enable loop guard on a port connecting user terminals. Otherwise, the port will stay in the
•
discarding state in all MSTIs because it cannot receive BPDUs.
Among loop guard, root guard and edge port settings, only one function (whichever is configured the
•
earliest) can take effect on a port at the same time.
Enabling TC-BPDU guard
When receiving topology change (TC) BPDUs (the BPDUs used to notify topology changes), a router
flushes its forwarding address entries. If someone forges TC-BPDUs to attack the router, the router will
receive a large number of TC-BPDUs within a short time and be busy with forwarding address entry
flushing. This affects network stability.
With the TC-BPDU guard function, you can set the maximum number of immediate forwarding address
entry flushes that the router can perform every a certain period of time (10 seconds). For TC-BPDUs
received in excess of the limit, the router performs forwarding address entry flush when the time period
expires. This prevents frequent flushing of forwarding address entries.
To enable TC-BPDU guard:
Step
1. Enter system view.
2. Enable the TC-BPDU guard function.
3. Configure the maximum number of
forwarding address entry flushes that the
router can perform every 10 seconds.
NOTE:
H3C does not recommend you disable this feature.

Displaying and maintaining the spanning tree

Task
Display information about ports blocked
by spanning tree protection functions.
Display BPDU statistics on ports.
Display information about ports shut
down by spanning tree protection
functions.
Display the historical information of port
role calculation for the specified MSTI or
all MSTIs.
Command
system-view
stp tc-protection enable
stp tc-protection threshold
number
Command
display stp abnormal-port [ | { begin |
exclude | include } regular-expression ]
display stp bpdu-statistics [ interface
interface-type interface-number [ instance
instance-id ] ] [ | { begin | exclude |
include } regular-expression ]
display stp down-port [ | { begin |
exclude | include } regular-expression ]
display stp [ instance instance-id ] history
[ slot slot-number ] [ | { begin | exclude |
include } regular-expression ]
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Remarks
N/A
Optional.
By default, TC-BPDU guard is
enabled.
Optional.
The default setting is 6.
Remarks
Available in any view
Available in any view
Available in any view
Available in any view