All ports are OPEN. Honeypot.

Writeup: http://www.korznikov.com/2014/10/every-port-is-open-for-security.html

Dependencies: iptables ipset

Make sure to add these rules to iptables:

iptables -A OUTPUT -p tcp -m tcp --tcp-flags RST RST -j DROP iptables -A OUTPUT -p icmp -m icmp --icmp-type 3 -j DROP iptables -t nat -A PREROUTING -p tcp -m set --match-set set_name dst -j REDIRECT --to-ports 8888

Then run some application, that will listen on 8888 port:

socat TCP-LISTEN:8888,reuseaddr,fork -

op_generate.py

will generate ipset within 1-65535 ports range and will exclude currently opened ports.

op_monitor.py

script that monitor netstat output for newly opened/closed ports, then add it or remove from ipset.