H3C Technologies H3C WX5500E Series Access Controllers User Manual
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Configuring the mode a port uses to recognize and
send MSTP packets
A port can receive and send MSTP packets in the following formats:
•
dot1s—802.1s-compliant standard format
•
legacy—Compatible format
By default, the packet format recognition mode of a port is auto. The port automatically distinguishes the
two MSTP packet formats, and determines the format of packets that it will send based on the recognized
format.
You can configure the MSTP packet format on a port. When operating in MSTP mode after the
configuration, the port sends and receives only MSTP packets of the format that you have configured to
communicate with devices that send packets of the same format.
MSTP provides MSTP packet format incompatibility guard. 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 MSTP packet format frequent change guard. If a port receives MSTP packets of different
formats frequently, the MSTP packet format configuration contains errors. If the port is operating in MSTP
mode, it will be shut down for protection. Ports disabled in this way can be re-activated after a detection
interval. For more information about the detection interval, see Fundamentals Configuration Guide.
To configure the MSTP packet format to be supported on a port or a group of ports:
Step Command Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view or port
group view.
•
Enter Layer 2 Ethernet interface view or
Layer 2 aggregate interface view:
interface interface-type
interface-number
•
Enter port group view:
port-group manual port-group-name
Use one of the commands.
3.
Configure the mode that the
port uses to recognize/send
MSTP packets.
stp compliance { auto | dot1s | legacy }
The default setting is auto.
Enabling outputting port state transition information
In a large-scale spanning tree network, 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.
To enable outputting port state transition information:
Step Command Remarks
1.
Enter system view.
system-view
N/A