3com S7906E Manuel De Montage
1-23
Sometimes a device may fail to receive a BPDU from the upstream device because the upstream
device is busy. A spanning tree calculation that occurs in this case not only is unnecessary, but also
wastes the network resources. In a very stable network, you can avoid such unwanted spanning tree
calculations by setting the timeout factor to 5, 6, or 7.
device is busy. A spanning tree calculation that occurs in this case not only is unnecessary, but also
wastes the network resources. In a very stable network, you can avoid such unwanted spanning tree
calculations by setting the timeout factor to 5, 6, or 7.
Follow these steps to configure the timeout factor:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Configure the timeout factor of the device stp timer-factor factor
Required
3 by default
3 by default
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.
hello time. The maximum rate of a port is related to the physical status of the port and the network
structure.
Make this configuration on the root bridge and on the leaf nodes separately.
Follow these steps to configure the maximum rate of a port or a group of ports:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet interface
view, or Layer 2
aggregate interface
view
view, or Layer 2
aggregate interface
view
interface interface-type
interface-number
interface-number
Enter
interface
view or port
group view
interface
view or port
group view
Enter port group view
port-group manual
port-group-name
port-group-name
Required
Use either command.
Use either command.
Configure the maximum rate of the
ports
ports
stp transmit-limit
limit
Required
10 by default
10 by default
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 MSTP from using excessive network resources when the
network becomes instable. We recommend that you use the default setting.
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 MSTP from using excessive network resources when the
network becomes instable. We recommend that you use the default setting.
Configuring Ports as Edge Ports
If a port directly connects to a user terminal rather than another device or a shared LAN segment, this
port is regarded as an edge port. When a network topology change occurs, an edge port will not cause
a temporary loop. Because a device does not know whether a port is directly connected to a terminal,
you need to manually configure the port to be an edge port. After that, this port can transition rapidly
from the blocked state to the forwarding state without delay.
port is regarded as an edge port. When a network topology change occurs, an edge port will not cause
a temporary loop. Because a device does not know whether a port is directly connected to a terminal,
you need to manually configure the port to be an edge port. After that, this port can transition rapidly
from the blocked state to the forwarding state without delay.