Configuring The Path Cost Of A Port - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide
Table 38-14 Configure a port as an edge port or a non-edge port
Configure a port as an edge port.
Configure a port as a non-edge port.
Restore the default setting of the port as
a non-edge port.
You can configure a port as an edge port or a non-edge port with either of the
earlier-mentioned measures.
After configured as an edge port, the port can fast transit from blocking state to
forwarding state without any delay. You can only set the port connecting with the
terminal as an edge port.In the case that BPDU protection has not been enabled on the
switch, the configured edge port will turn into a non-edge port again when it receives
BPDU from other ports. In the case that BPDU protection is enabled, the port will be
disabled. The configuration of this parameter takes effect on all the STIs. In other words,
if a port is configured as an edge port or non-edge port, it is configured the same on all
the STIs.
It is better to configure the BPDU protection on the edged port, so as to prevent the
switch from being attacked.
Before BPDU protection is enabled on the switch, the port runs as a non-edge port
when it receives BPDU, even if the user has set it as an edge port.
If BPDU protection is enabled on the switch, the port is disabled. Only the network
administrators can enable the port.
By default, all the Ethernet ports of the switch have been configured as non-edge ports.
Note:
It is better to configure the port directly connected with the terminal as an edge port,
and enable the BPDU function on the port. That is, to realize fast state-transition and
prevent the switch from being attacked.

38.2.11 Configuring the Path Cost of a Port

Path Cost is related to the speed of the link connected to the port. On the MSTP switch,
a port can be configured with different path costs for different STIs. Thus the traffic from
different VLANs can run over different physical links, thereby implementing the
VLAN-based load-balancing.
You can configure the path cost of a port in the following ways.
Operation
38-23
Chapter 38 MSTP Region-configuration
Command
stp edged-port enable
stp edged-port disable
undo stp edged-port