The number of cases I have that are "China" but are actually VTP, Do not use VTP Never use VTP especially in your legacy industrial environments somebody is gonna plug a switch in send toot
you mean people actually use it on purpose!? I guess it might be the sort of thing that is maybe tempting to use in an enterprise environment if you haven't understood how it works and the resulting risks. Fortunately I learned with "service provider mindset" as we acquired a SP network with some Cisco in it ~20 years ago and when I took the cisco press books on holiday to learn how to run my new network, the immediate determination on VTP was: "no, never that"