I did this as a result of following a (poorly-conceived) iptables tutorial. 'Step one: configure iptables to deny traffic by default: iptables -P INPUT DROP'

I did this as a result of following a (poorly-conceived) iptables tutorial. 'Step one: configure iptables to deny traffic by default: iptables -P INPUT DROP' There's also the time that I learned why you should think twice before setting a default policy of DROP or REJECT - iptables -F will clear all rules that allow you in, but not the default policy that keeps you out.