User's Manual

Table Of Contents
239
Users Manual of CS-6306R
The main function of the compatible mode is to create the MST area for switches
and other MSTP-running switches. In actual networking, make sure that the switch
has the same configuration name and the same edit number. It is recommended to
configure switches running other MSTP protocols to the CIST root, ensuring that the
switch enters the compatible mode by receiving message.
If the MST-compatible mode is not activated, the switch will not resolve the whole
BPDU-compatible content and take the content as the common RSTP BPDU. In
this way, the switch cannot be in the same area with the MST-compatible switch
that it connects.
A port in compatible mode cannot automatically resumes to send standard MST
BPDU even if the compatible mode is shut down in global configuration mode. In
this case, run migration-check.
19.2.3.14 Restarting Protocol Conversion Check
MSTP allows the switch to work with the traditional STP switch through protocol conversion mechanism. If
one port of the switch receives the STP configuration message, the port then only transmits the STP message.
At the same time, the port that receives the STP information is then considered as a boundary port.
When a port is in the STP-compatible state, the port will not automatically resume to
the MSTP state even if the port does not receive the STP message any more. In
this case, you can run spanning-tree mstp migration-check to clear the STP
message that the port learned, and make the port to return to the MSTP state.
The switch that runs the RSTP protocol can identify and handle the MSTP
message. Therefore, the MSTP switch does not require protocol conversion when it
works with the RSTP switch.
In global configuration mode, run the following command to clear all STP information that is detected by all
ports of the switch:
Command Purpose
spanning-tree mstp migration-check Clears all STP information that is detected by all
ports of the switch.
In port configuration mode, run the following command to clear STP information detected by the port.
Command Purpose
spanning-tree mstp migration-check Clears STP information detected by the port.