CALCULATION OF RELIEF information on the role and status for copies of the set Spanning Tree

摘要

In an embodiment of the present invention, a method comprises a plurality of operations. An operation is performed for receiving a data transmission unit at a boundary port (225) of a first region bridge (215). The data transmission unit is transmitted from a second region bridge (220) for reception by the first region bridge (215). An operation is performed for carrying out Port Information Machine (PIM) Superior_Designated state computation for a Common and Internal Spanning Tree (CIST) instance in response to receiving the data transmission unit. An operation is performed for initiating Port Role Selection (PRS) state computation for each one of a plurality of Multiple Spanning Tree Instances (MSTIs) associated with the CIST in response to initiating the operation of PIM Superior_Designated state computation being performed.