Adding a Port to an MSTP Process

Context

After being added to MSTP processes, interfaces can participate in MSTP calculation. The links connecting MSTP-enabled devices and access rings are called access links, and the link shared by multiple access rings is called a shared link. Interfaces on this shared link participate in MSTP calculation in multiple access rings and MSTP processes.

Procedure

Adding a port on an access link to an MSTP process
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The Ethernet interface view is displayed.
  
  The interface specified in this command must be the interface that connects the device and the access ring.
3. Run stp binding process process-id
  The port is added to the specified MSTP process.
  
  On the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731S-H, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730S-H, and S6730-H, if an interface joining the MSTP process has sub-interfaces configured with other features such as VPLS, run the stp vpls-subinterface enable command. The main interface can then notify its sub-interfaces to update MAC address entries and ARP entries after receiving a TC-BPDU. This prevents service interruption. In addition, root protection needs to be configured on the main interface.
Adding a port on a shared link to an MSTP process
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The view of the Ethernet interface that participates in spanning tree calculation is displayed.
  
  The interface specified in this command must be an interface on the shared link between the devices configured with MSTP multi-process. It cannot be an interface that connects an access ring and device.
3. Run stp binding process process-id1 [ to process-id2 ] link-share
  The port is added to multiple MSTP processes to complete MSTP calculation.
  
  In an MSTP process where there are multiple shared links, run the stp enable command in the MSTP multi-instance view. On an interface that is added to an MSTP process, run the stp enable command in the interface view.