3Com 7700 Configuration Manual page 240

232 C 8: STP O
HAPTER PERATION
Configuring a Port as an
Edge Port
Configuring the Path
Cost of a Port
An edge port refers to the port not directly connected to any switch or indirectly
connected to a switch over the connected network.
You can configure a port as an edge port or non-edge port in the following ways.
Configuring in System View
Perform the following configuration in system view.
Table 29 Configure a Port as an Edge Port or a Non-edge Port
Operation
Configure a port as an edge port.
Configure a port as a non-edge port.
Restore the default setting, non-edge port, of
the port.
Configuring in Ethernet Port View
Perform the following configuration in Ethernet port view.
Table 30 Configure a Port as an Edge Port or a Non-edge Port
Operation
Configure a port as an edge port.
Configure a port as a non-edge port.
Restore the default setting, non-edge port, of
the port.
For more about the commands, see the Switch 7700 Command Reference Guide.
After it is configured as an edge port, the port can transit rapidly from a blocking
state to a forwarding state without any delay. In the case that BPDU protection has
not been enabled on the switch, the configured edge port will turn into non-edge
port again when it receives BPDU from the other port. In case BPDU protection is
enabled, the port will be disabled. The this parameter is configured the same and
takes effect on all the STIs.
It is better to configure the BPDU protection on the edge 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.
By default, all the Ethernet ports of the switch have been configured as non-edge
ports.
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.
Command
stp interface interface-list edged-port
enable
stp interface interface-list edged-port
disable
undo stp interface interface-list edged-port
Command
stp edged-port enable
stp edged-port disable
undo stp edged-port