I have iptables rules on 10.04 and older versions of Ubuntu, with which (iptebles-restore < /folder/file_ipt_rules) internet is working, they are:
*filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT DROP [0:0] -A INPUT -m iprange --dst-range 192.168.0.0-192.168.1.255 -m limit --limit1/minute --limit-burst 1 -m state --state NEW -j LOG --log-prefix " INPUT STATE NEW " -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A OUTPUT -d 126.96.36.199/24 -j DROP -A OUTPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT COMMIT
This ruleset drops new connections to my Desktop because it is allowed only related and established connections (-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT) and logs attempts of new connections to /var/log/messages (old versions of Ubuntu!) But, this set of rules drops internet on 16.10. Why? P.S. Against hackers works excellent. Only from time to time I am tired of DDoS attacks.