Setting The Timeout Factor; Setting The Bpdu Transmission Rate - H3C S7500E-X Configuration Manual

Step
Set the max age timer.
4.

Setting the timeout factor

The timeout factor is a parameter used to decide the timeout period. The formula for calculating the
timeout period is: timeout period = timeout factor × 3 × hello time.
On a stable network, each non-root-bridge device forwards configuration BPDUs to the downstream
devices at the hello time interval to detect link failures. If a device does not receive a BPDU from the
upstream device within nine times the hello time, it assumes that the upstream device has failed.
Then, it starts a new spanning tree calculation process.
An upstream device might be too busy to forward configuration BPDUs in time, for example, many
Layer 2 interfaces are configured on the upstream device. As a result, the downstream device fails to
receive a BPDU within the timeout period and then starts an undesired spanning tree calculation.
The calculation might fail, and it also wastes network resources. To prevent undesired spanning tree
calculation and save network resources on a stable network, you can set the timeout factor to 5, 6, or
7.
To set the timeout factor:
Step
Enter system view.
1.
Set the timeout factor of the
2.
device.

Setting the BPDU transmission rate

The maximum number of BPDUs a port can send within each hello time equals the BPDU
transmission rate plus the hello timer value. Set an appropriate BPDU transmission rate based on
the physical status of the port and the network structure.
The higher the BPDU transmission rate, the more BPDUs are sent within each hello time, and the
more system resources are used. By setting an appropriate BPDU transmission rate, you can limit
the rate at which the port sends BPDUs. Setting an appropriate rate also prevents spanning tree
protocols from using excessive network resources when the network topology changes. As a best
practice, use the default setting.
To set the BPDU transmission rate:
Step
Enter system view.
1.
Enter Layer 2 Ethernet or
2.
aggregate interface view.
Set the BPDU transmission
3.
Command
stp vlan vlan-id-list timer hello
time
•
In STP/RSTP/MSTP mode:
stp timer max-age time
•
In PVST mode:
stp vlan vlan-id-list timer
max-age time
Command
system-view
stp timer-factor factor
Command
system-view
interface interface-type
interface-number
stp transmit-limit limit
80
Remarks
The default setting is 20 seconds.
Remarks
N/A
The default setting is 3.
Remarks
N/A
N/A
The default setting is 10.