NOTE
l RSTP uses a single spanning tree instance on the entire network. As a result, performance deterioration
cannot be prevented when the network scale grows. Therefore, the network diameter cannot be larger
than 7.
l It is recommended that you run the stp bridge-diameter diameter command to set the network
diameter. Then, the switching device calculates the optimal Forward Delay timer value, Hello timer
value, and Max Age timer value based on the configured network diameter.
----End
6.6.2.2 Setting the STP Timeout Interval
Context
If a device does not receive any BPDUs from the upstream device within the timeout interval,
the device considers the upstream device to have failed and recalculates the spanning tree.
Sometimes, a device cannot receive the BPDU from the upstream device within the timeout
interval because the upstream device is busy. In this case, recalculating the spanning tree will
cause a waste of network resources. To avoid wasting network resources, set a long timeout
interval on a stable network.
If a switching device does not receive any BPDUs from the upstream device within the timeout
interval, spanning tree recalculation is performed. The timeout interval is calculated as follows:
Timeout interval = Hello time x 3 x Timer Factor
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Run:
stp timer-factor factor
The Timer Factor value is set. This parameter determines the timeout interval during which the
device waits for BPDUs from the upstream device.
By default, the timeout period is 9 times the Hello timer value.
----End
6.6.2.3 Setting the STP Timers
Context
The following timers are used in spanning tree calculation:
l Forward Delay: specifies the delay before a state transition. After the topology of a ring
network changes, it takes some time to spread the new configuration BPDU throughout the
entire network. As a result, the original blocked port may be unblocked before a new port
is blocked. When this occurs, a loop exists on the network. You can set the Forward Delay
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
6 STP/RSTP Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
196
To Next Page
Loading...
