## Block SSH brute force attacks
iptables -N brute_force
iptables -F brute_force
iptables -A brute_force -m state --state NEW -m recent --name attack --set
iptables -A brute_force -m recent --name attack --rcheck --seconds 120 --hitcount 3 -m limit --limit 2/minute --limit-burst 1 -j LOG --log-prefix 'SSH brute force attack '
iptables -A brute_force -m recent --name attack --rcheck --seconds 120 --hitcount 3 -j DROP
iptables -A brute_force -j ACCEPT
## Open SSH port
iptables -A INPUT -p tcp --syn --dport 22 -j brute_force
#iptables -A INPUT -p udp --syn --dport 5060 -j brute_force