Simple question with an equally simple answer I am sure:
When a non-root switch port transitions from blocking to forwarding a TCN will be generated so that all switches will know of the change and can readjust as necessary to prevent data loops. This TCN, I believe, is sent out the root port as that is the quickest route to the root bridge. Along the way other non-root switches could receive this TCN before it reaches the root bridge. For these intermediate switches: do they change their MAC address table timeout from 300 secs to 15 secs as they receive this TCN from the downstream switch or do they wait until the root switch issues the “authorization” TCN?