I managed to take down an entire school network with one VPN.

In short, I ran a personal VPN and eventually the System Administrators at my old school managed to pick it up as unknown traffic. For some reason, they managed to block the port but not the IP so I changed the port to 443 and their automatic system blocked port 443 on their entire network essentially rendering HTTPS useless for a few hours.

I never got approached about it but my school invested in a new IT team.

Nice one. I know a guy who killed the whole hospital's computer network with a single ICMP packet. Killed it for good -- all the NW infra had to be rebooted :)

@netikras That's absolutely devastating

@brigdeer Indeed it is. A couple years later the same guy nearly killed the same hospital NW again by trying to connect to his work VPN while connected to the hospital's public hotspot. Ping in LAN rose up to 3.5-4s (4s == timeout). Thankfully the NW did not go down completely. We did not find out what was causing the lag exactly except that it is somehow related to the VPN. Your post reminded of this bit initially as you both managed to compromise the whole NW using VPN :)

Someone really needs to invest more in the hospital's IT and clean all the mess up...