iptables

#
# Configurations
#
INTERNET=eth1
#
# reset the default policies in the filter table.
#
iptables -P INPUT ACCEPT
# das standardverhalten für den filter wird auf DROP gesetzt. nur wenn ein paket unten auf Grund der MAC erlaubt wird kommt es durch.
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT


#
# reset the default policies in the nat table.
#
iptables -t nat -P PREROUTING ACCEPT
iptables -t nat -P POSTROUTING ACCEPT
iptables -t nat -P OUTPUT ACCEPT


#
# reset the default policies in the mangle table.
#
iptables -t mangle -P PREROUTING ACCEPT
iptables -t mangle -P OUTPUT ACCEPT


#
# flush all the rules in the filter and nat tables.
#
iptables -F
iptables -t nat -F
iptables -t mangle -F
#
# erase all chains that's not default in filter and nat table.
#
iptables -X
iptables -t nat -X
iptables -t mangle -X


#
# MASQUERADING EINSCHALTEN
#
iptables -A POSTROUTING -t nat --out-interface $INTERNET -j MASQUERADE


#
# MAC FILTERING
#


TMPFILE=/tmp/macolny
MACFILE=./allow_mac
grep -i '^[0-F]' $MACFILE > $TMPFILE


for i in `cat $TMPFILE`
do
echo $i
iptables -A FORWARD -m mac -t filter --mac-source $i -j ACCEPT
done




rm $TMPFILE
echo "FIREWALL RESTARTED"