@hacks4pancakes that reminds of the best lesson of my early IT life, I learned VTP very quickly, took me an hour or two to restore what blew up.
Good lessons, horrible protocol, should die on the lowest level of hell.
I feel sorry for people with big switching networks that do not read the fine print.
@mlukaszuk This is why it is super important to have other experiences in systems and network administration going into security because stuff like this happens and they're like "switchports are flashing, network is dead, it's China"