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 determine whether a port is directly connected to a
terminal, you must manually configure the port as an edge port. After that, the port can transition rapidly
from the blocked state to the forwarding state.
Make this configuration on the root bridge and on the leaf nodes separately.
Follow these steps to specify a port or a group of ports as edge port or ports:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet interface view
or Layer 2 aggregate
interface view
interface
interface-type
interface-number
Enter interface
view or port
group view
Enter port group view
port-group manual
port-group-name
Required
Use either command.
Configure the current ports as edge ports
stp
edged-port enable
Required
All ports are non-edge ports
by default.
NOTE:
•
If BPDU guard is disabled, a port set as an edge port will become a non-edge port again if it receives
a BPDU from another port. To restore the edge port, re-enable it.
•
If a port directly connects to a user terminal, configure it as an edge port and enable BPDU guard for it.
This enables the port to transition to the forwarding state quickly while ensuring network security.
Otherwise, the port can be blocked and changes to the forwarding state after a period twice the
Forward Delay. In the waiting period, service traffic is interrupted.
•
Among loop guard, root guard and edge port settings, only one function (whichever is configured the
earliest) can at a time take effect on a port.
Configuring path costs of ports
Path cost is a parameter related to the rate of a port. On an MSTP-enabled device, a port can have
different path costs in different MSTIs. Setting appropriate path costs allows VLAN traffic flows to be
forwarded along different physical links, achieving VLAN-based load balancing.
You can have the device automatically calculate the default path cost, or you can configure the path cost
for ports.
Make the following configurations on the leaf nodes only.
Specifying a standard that the device uses when it calculates the default path cost
You can specify a standard for the device to use in automatic calculation for the default path cost. The
device supports the following standards:
•
dot1d-1998
—The device calculates the default path cost for ports based on IEEE 802.1d-1998.
•
dot1t
—The device calculates the default path cost for ports based on IEEE 802.1t.
•
legacy
—The device calculates the default path cost for ports based on a private standard.
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