3Com Switch 8800 Advanced Software V5 Configuration Guide

116 CHAPTER 11: MSTP CONFIGURATION
Configuration example
# Set the forward delay to 1,600 centiseconds, hello time to 300 centiseconds,
and max age to 2,100 centiseconds.
<Sysname> system-view
[Sysname] stp timer forward-delay 1600
[Sysname] stp timer hello 300
[Sysname] stp timer max-age 2100
Configuring the Timeout
Factor
A device sends hello packets to the devices around it at a specific interval to check
whether any link is faulty. Typically, if a device does not receive a BPDU from the
upstream device within a period three times the hello time, it will assume that the
upstream device has failed and start a new spanning tree computing process.
In a very stable network, this kind of spanning tree computing may occur because
the upstream device is busy. In this case, you can avoid such unwanted spanning
tree computing by lengthening the timeout time.
Configuration procedure
Follow these steps to configure the timeout factor:
n
■ Timeout time = timeout factor × hello time.
■ Typically, we recommend that you set the timeout factor to 5, 6, or 7 for a
stable network.
Configuration example
# Set the timeout factor to 6.
<Sysname> system-view
[Sysname] stp timer-factor 6
Configuring the
Maximum Transmission
Rate of Ports
The maximum transmission rate of a port refers to the maximum number of MSTP
packets that the port can send within each hello time.
The maximum transmission rate of an Ethernet port is related to the physical
status of the port and the network structure.
Configuration procedure
Following these steps to configure the maximum transmission rate of a port or a
group of ports:
To do... Use the command... Remarks
Enter system view system-view -
Configure the timeout factor
of the device
stp timer-factor number Optional
3 by default
To do... Use the command... Remarks
Enter system view system-view -