3Com Switch 8800 Family Configuration Guide

Configuring MSTP 141
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. 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.
If BPDU protection is enabled on the switch, the edged port is disabled when it
receives BPDU packets from the user. Only the network administrators can enable
the port.
By default, all the Ethernet ports of the switch have been configured as non-edge
ports.
n
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.
c
CAUTION: If STP has been enabled on the equipment connected to the switch, do
not configure the edged ports on the equipment. Otherwise the system will fail to
delete MAC address entries and ARP address entries on the port.
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.
Configuration in system view
Perform the following configuration in system view.
Configuration in Ethernet port view
Perform the following configuration in Ethernet port view.
Tab le 118 Configure a port as an edge port or a non-edge port
Operation Command
Configure a port as an edge port stp edged-port enable
Configure a port as a non-edge port stp edged-port disable
Restore the default setting of the port as a
non-edge port
undo stp edged-port
Tab le 119 Configure the path cost of a port
Operation Command
Configure the path cost of a port
stp interface interface-list [ instance
instance-id ] cost cost
Restore the default path cost of a port
undo stp interface interface-list [ instance
instance-id ] cost