Iptables : script per proteggere la propria rete da spam scan e attacchi dDoS

#!/bin/bash
FILE="/tmp/drop.lasso"
URL="http://www.spamhaus.org/drop/drop.lasso"
echo ""
echo -n "Aggiunta/Inserimento regole DROP al firewall iptables ..."
[ -f $FILE ] && /bin/rm -f $FILE || :
cd /tmp
wget $URL
blocks=$(cat $FILE  | egrep -v '^;' | awk '{ print $1}')
iptables -N droplist
for ipblock in $blocks
do
 iptables -A droplist -s $ipblock -j LOG --log-prefix "DROP List Block"
 iptables -A droplist -s $ipblock -j DROP
done
iptables -I INPUT -j droplist
iptables -I OUTPUT -j droplist
iptables -I FORWARD -j droplist
echo "... Firewall Attivato"
/bin/rm -f $FILE