Assume that you install a new bridge and it contains the lowest BID in the network. Further assume that this devices is running experimental Beta code that contains a severe memory leak and, as a result, reboots every 10 minutes. What effect does this have on the network?
STP is a preemptive protocol that constantly seeks the Root Bridge with the lowest BID. Therefore, in this network, the new bridge wins the Root War, and the entire active topology converges on this bridge every ten minutes. Where links change state during this convergence process, temporary outages of 30–50 seconds occur. When the bridge fails several minutes later, the network converges on the next most attractive Root Bridge and creates another partial network outage for 30–50 seconds.
In short, the network experiences partial outages every time the new bridge restarts and fails.