iptables -N conn-flood
iptables -I INPUT 1 -p tcp --syn -j conn-flood
iptables -A conn-flood -m limit -–limit 7/s –-limit-burst 20 -j RETURN
iptables -A conn-flood -j DROP
iptables -A INPUT -p icmp -m limit --limit 1/s --limit-burst 1 -j ACCEPT
iptables -A INPUT -p icmp -j DROP
iptables -I INPUT -p tcp -m state --state NEW,ESTABLISHED -m recent --set -j ACCEPT
iptables -I INPUT -p tcp -m state --state NEW -m recent --update --seconds 3 --hitcount 20 -j DROP



Koob:


iptables -t raw -N ANTIDOS
iptables -t raw -A ANTIDOS -m hashlimit --hashlimit 5/s --hashlimit-name limitDoS --hashlimit-mode srcip -j ACCEPT
iptables -t raw -A ANTIDOS -j DROP
iptables -t raw -A PREROUTING -i eth0 -p tcp --syn --dport 80 -j ANTIDOS