Configuring The Timeout Factor; Configuring The Maximum Port Rate - HP 5120 EI Series Lan Switching Configuration Manual

Step
3. Configure the hello timer.
4. Configure the max age
timer.

Configuring the timeout factor

The timeout factor is a parameter used to decide the timeout time, in the following formula: Timeout time
= timeout factor × 3 × hello time.
After the network topology is stabilized, each non-root-bridge device forwards configuration BPDUs to
the downstream devices at the interval of hello time to determine whether any link is faulty. 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 and starts a new spanning tree calculation process.
Sometimes a device might fail to receive a BPDU from the upstream device because the upstream device
is busy. If a spanning tree calculation occurs, the calculation can fail and also waste network resources.
In a stable network, you can prevent undesired spanning tree calculations by setting the timeout factor to
5, 6, or 7.
To configure the timeout factor:
Step
1. Enter system view.
2. Configure the timeout factor of the
device.

Configuring the maximum port rate

The maximum rate of a port refers to the maximum number of BPDUs the port can send within each hello
time. The maximum rate of a port is related to the physical status of the port and the network structure.
The higher the maximum port rate is, the more BPDUs will be sent within each hello time, and the more
system resources will be used. By setting an appropriate maximum port rate, you can limit the rate at
which the port sends BPDUs and prevent spanning tree protocols from using excessive network resources
when the network becomes unstable. HP recommends you to use the default setting.
To configure the maximum rate of a port or a group of ports:
Step
1. Enter system view.
Command
•
In STP/RSTP/MSTP mode:
stp timer hello time
•
In PVST mode:
stp vlan vlan-list timer hello time
•
In STP/RSTP/MSTP mode:
stp timer max-age time
•
In PVST mode:
stp vlan vlan-list timer max-age time
Command
system-view
stp timer-factor factor
Command
system-view
80
Remarks
Optional.
Use one of the commands.
The default setting is 2
seconds.
Optional.
Use one of the commands.
The default setting is 20
seconds.
Remarks
N/A
3 by default.
Remarks
N/A