Automatically Inheriting Ports--MSTP Only

In an MSTP (Multiple Spanning Tree Protocol) environment, whether you manually or automatically bind a port to an MSTI (Multiple Spanning Tree Instances) in an MSTP region, the switch automatically binds that port to the CIST.

The CIST handles BPDU processing for itself and all of the MSTIs; therefore, the CIST must inherit ports from the MSTIs in order to transmit and receive BPDUs. You can only delete ports from the CIST if it is no longer a member of an MSTI.

For more information about MSTP, see Multiple Spanning Tree Protocol.