NOTE:
•
MSTP provides the MSTP packet format incompatibility guard function. In MSTP mode, if a port is
configured to recognize/send MSTP packets in a mode other than
auto
, and if it receives a packet in a
format different from the specified type, the port becomes a designated port and remains in the
discarding state to prevent the occurrence of a loop.
•
MSTP provides the MSTP packet format frequent change guard function. If a port receives MSTP packets
of different formats frequently, the MSTP packet format configuration can contain errors. If the port is
working in MSTP mode, it will be disabled for protection. Only network administrators can restore those
closed ports.
Enabling the output of port state transition information
A large-scale, MSTP-enabled network can have many MSTIs, and ports might frequently transition from
one state to another. In this situation, you can enable devices to output the port state transition
information of all MSTIs or the specified MSTI in order to monitor the port states in real time.
Make this configuration separately on the root bridge and on the leaf nodes.
Follow these steps to enable output of port state transition information:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enable output of port state
transition information
stp port-log
{
all | instance
instance-id
}
Required
Enabled by default.
Enabling the MSTP feature
You must enable MSTP for the device before any other MSTP-related configurations can take effect.
Make this configuration on the root bridge and on the leaf nodes separately.
Follow these steps to enable the MSTP feature:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enable the MSTP feature globally
stp enable
Required
MSTP is globally disabled by
default.
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.
Enable the MSTP feature for the ports
stp
enable
Optional
By default, MSTP is enabled for
all ports after it is enabled for
the device globally.
72