Configuring The Maximum Port Rate; Configuring Ports As Edge Ports - 3Com S7906E Configuration Manual

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.
Follow these steps to configure the timeout factor:
Enter system view
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.
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:
Enter system view
Enter
interface
view or port
group view
Configure the maximum rate of the
ports
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.

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.
To do...
To do...
Enter Ethernet interface
view, or Layer 2
aggregate interface
view
Enter port group view
Use the command...
system-view
stp timer-factor factor
Use the command...
system-view
interface interface-type
interface-number
port-group manual
port-group-name
stp transmit-limit limit
1-23
Remarks
—
Required
3 by default
Remarks
—
Required
Use either command.
Required
10 by default