# Adjust "--connlimit-above NNN" to the maximum total connections you
#   want your web server to support
iptables -t filter -I INPUT -p tcp --syn --dport 80 -m connlimit --connlimit-above 500 -j DROP
iptables -t filter -I INPUT -p tcp --syn --dport 443 -m connlimit --connlimit-above 500 -j DROP

##Limit ping
#iptables -A INPUT -p icmp -m icmp --icmp-type address-mask-request -j DROP
#iptables -A INPUT -p icmp -m icmp --icmp-type timestamp-request -j DROP
#iptables -A INPUT -p icmp -m icmp --icmp-type 8 -m limit --limit 5/second -j ACCEPT

# flooding of RST packets, smurf attack Rejection
iptables -A INPUT -p tcp -m tcp --tcp-flags RST RST -m limit --limit 2/second --limit-burst 2 -j ACCEPT

# Protecting portscans
# Attacking IP will be locked for 24 hours (3600 x 24 = 86400 Seconds)
iptables -A INPUT -m recent --name portscan --rcheck --seconds 86400 -j DROP
iptables -A FORWARD -m recent --name portscan --rcheck --seconds 86400 -j DROP

# Remove attacking IP after 24 hours
iptables -A INPUT -m recent --name portscan --remove
iptables -A FORWARD -m recent --name portscan --remove

# These rules add scanners to the portscan list, and log the attempt.
iptables -A INPUT -p tcp -m tcp --dport 139 -m recent --name portscan --set -j LOG --log-prefix "portscan:"
iptables -A INPUT -p tcp -m tcp --dport 139 -m recent --name portscan --set -j DROP

iptables -A FORWARD -p tcp -m tcp --dport 139 -m recent --name portscan --set -j LOG --log-prefix "portscan:"
iptables -A FORWARD -p tcp -m tcp --dport 139 -m recent --name portscan --set -j DROP