Which statement is true about TCN propagation?
A. The originator of the TCN immediately floods this information through the network.
B. The TCN propagation is a two step process.
C. A TCN is generated and sent to the root bridge.
D. The root bridge must flood this information throughout the network.
TCNs no longer used in 802.1w.
In 802.1w, it only uses TC and TCAck. Only when the TCN is used, is the propagation to legacy bridges.
RSTP no longer uses the specific TCN BPDU, unless a legacy bridge needs to be notified
http://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/24062-146.html
In 802.1D, the bridge propagate TCN to the Root Bridge, and then Root Bridge broadcasts the TC bit to the whole topology.
