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Configuration example
# Set the bridge priority of the current device to 4,096 in spanning tree instance 1.
<device> system-view
[device] stp instance 1 priority 4096
Configuring the Mode a Port Recognizes and Sends MSTP Packets
A port can be configured to recognize and send MSTP packets in the following modes.
z Automatic mode. Ports in this mode determine the format of the MSTP packets to be sent
according to the format of the received packets.
z Legacy mode. Ports in this mode recognize/send packets in legacy format.
z 802.1s mode. Ports in this mode recognize/send packets in dot1s format.
A port acts as follows according to the format of MSTP packets forwarded by a peer device or router.
When a port operates in the automatic mode:
z The port automatically determines the format (legacy or dot1s) of received MSTP packets and then
determines the format of the packets to be sent accordingly, thus communicating with the peer
devices.
z If the format of the received packets changes repeatedly, MSTP will shut down the corresponding
port to prevent network storm. A port shut down in this way can only be brought up by the network
administrator.
When a port operates in the legacy mode:
z The port only recognizes and sends MSTP packets in legacy format. In this case, the port can only
communicate with the peer through packets in legacy format.
z If packets in dot1s format are received, the port turns to discarding state to prevent network storm.
When a port operates in the 802.1s mode:
z The port only recognizes and sends MSTP packets in dot1s format. In this case, the port can only
communicate with the peer through packets in dot1s format.
z If packets in legacy format are received, the port turns to discarding state to prevent network storm.
Configuration procedure
Follow these steps to configure the mode a port recognizes and sends MSTP packets (in system view):
To do… Use the command… Remarks
Enter system view system-view —
Configure the mode a port
recognizes and sends MSTP
packets
stp interface interface-type
interface-number compliance
{ auto | dot1s | legacy }
Required
By default, a port recognizes
and sends MSTP packets in the
automatic mode. That is, it
determines the format of
packets to be sent according to
the format of the packets
received.
Follow these steps to configure the mode a port recognizes and sends MSTP packets (in Ethernet port
view):