3Com 4800G Series, Configuration Manual

Page: 223 / 1246

Configuring the Root Bridge 223
Configuration procedure
Follow these steps to configure the MSTP packet format to be supported by a port
or a group of ports:
n
■
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 the format different from
the specified type, that port will become a designated port and remain in the
discarding state to prevent the occurrence of a loop.
■
If a port receives MSTP packets of different formats frequently, this means that
the MSTP packet formation configuration contains error. In this case, if the port
is working in MSTP mode, it will be disabled for protection. Those ports closed
thereby can be restored only by the network administers.
Configuration example
# Configure GigabitEthernet 1/0/1 to receive and send standard-format MSTP
packets.
<Sysname> system-view
[Sysname] interface GigabitEthernet 1/0/1
[Sysname-GigabitEthernet1/0/1] stp compliance dot1s
Enabling the Output of
Port State Transition
Information
In a large-scale, MSTP-enabled network, there are a large number of MSTP
instances, so ports may frequently transition from one state to another. In this
situation, you can enable the device to output the port state transition information
of all SPT instances or the specified SPT instance so as to monitor the port states in
real time.
Follow these steps to enable output of port state transition information:
To do… Use the command… Remarks
Enter system view system-view -
Enter
Ethernet
interface
view or
port group
view Enter
Ethernet
interface
view interface interface-type
interface-number
Required
Use either command.
Configurations made in
Ethernet interface view will take
effect on the current port only;
configurations made in port
group view will take effect on
all ports in the port group.
Enter port
group view port-group { manual
port-group-name | aggregation
agg-id }
Configure the mode the
port uses to
recognize/send MSTP
packets stp compliance { auto | dot1s |
legacy }
Optional
auto by default
To do… Use the command… Remarks
Enter system view system-view -
Enable output of port state
transition information of all
instances or a particular instance stp port-log { all | instance
instance-id }
Optional
Enabled by default