I've drop down two networks in my life, First time I run a dhcp server by accident and suddenly went sideways but the blast radius was small, Second time and

I've drop down two networks in my life, First time I run a dhcp server by accident and suddenly went sideways but the blast radius was small, Second time and more interesting one, My campus had a mac address allow list; when I got a new computer and didn't want to handle the process of updating my access access permission, I just run a script to change my mac to the old known address. Later, I also sold the old computer to another colleague which didn't bother to register as well since everything was working. Long story short, we keep disconnecting each other. One day I was, "c'mon, I'll fix this". Opened wireshark and started to capture network traffic. I've got a list of mac addresses from the pcap dump and every time I got disconnected, I ran the script spoofing my address to the next one in my list. That worked fine until the day I spoofed the mac address of a central managed switch that shit itself out of the network. :)