A method for providing Topology Change functionality in a Local Area
Network (LAN) comprises a plurality of operations. An operation is
performed for determining that a Multiple Spanning Tree Instance (MSTI)
Master port on a Bridge of a LAN has transitioned to Forwarding state
from a corresponding Common Internal Spanning Tree Instance (CSTI) Root
port state and an operation is performed for transitioning a Port
Transmit state machine of the Bridge from an Idle state to a Transmit
state for enabling issuance of a Topology Change (TC) BPDU message from
the MSTI Master port. The operation of transitioning the Port Transmit
state machine is performed in response to performing the operation of
determining that the Multiple Spanning Tree Instance (MSTI) Master port
has transitioned to Forwarding state.