I managed to run ip route delete default on a linux firewall box I was SSHing to over the internet.
Hadn't saved any config changes, so I rang the site guy and asked for a reboot please. Alll good so far.
Machine stops replying to ping, starts pinging, so I'm sitting there pressing up-arrow, enter, (SSH connect refused) up-arrow, enter (refused) over and over.
SSH starts, I press up-arrow, enter, get on the box with an SSH key so no password, then up-arrow, enter.
What was the last command? `ip route delete default `
That became the definition of Muppetty.