Both switches will send TCNs on it's root port towards the root bridge. Every intermediate switch should acknowledge the TCN BPDU and forward it out it's root port. The process will continue till the TCN makes it to the root bridge.
The upstream switch (designated bridge) to which the root port is connected will initiate the TCN bpdu towards the root bridge when the topology change occurred. Moreover, the blocked port state should change to root port and TCNs will get flooded out the newly designated root port as well.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...