Denkfehler, oder was? iptables Script-Problem

LAN_INTERFACE="eth0"
PPP_INF="ppp0"
LAN_IP="10.0.7.57"
LAN_RANGE="10.0.7.0/24"
LAN_BCAST="10.0.7.255"
IPTABLES="/sbin/iptables"

case "$1" in
start)

        echo -n $"Firewall hochfahren..."

        #Regeln loeschen
        $IPTABLES -F
        $IPTABLES -X

        #Default Policy
        $IPTABLES -P INPUT DROP
        $IPTABLES -P FORWARD DROP
        $IPTABLES -P OUTPUT ACCEPT

        #Loopback freigeben
        $IPTABLES -A INPUT -i lo -j ACCEPT
        $IPTABLES -A OUTPUT -o lo -j ACCEPT


        #SSH fuer Verwaltung aus dem Lan freigeben
        $IPTABLES -A INPUT -p tcp --dport 22 -i $LAN_INTERFACE -s $LAN_RANGE -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
        $IPTABLES -A OUTPUT -p tcp --sport 22 -o $LAN_INTERFACE -d $LAN_RANGE -m state --state ESTABLISHED,RELATED -j ACCEPT

        #Masquerading fuer alles ausgehenden Verbindungen
        $IPTABLES -t nat -A POSTROUTING -o $PPP_INF -j MASQUERADE

        #IP-Spoofing loggen und verhindern
        $IPTABLES -A FORWARD -s $LAN_RANGE -i $PPP_INF -j LOG --log-level 6 --log-prefix "FIREWALL:spoofing"
        $IPTABLES -A FORWARD -s $LAN_RANGE -i $PPP_INF -j DROP

        ;;
stop)
        echo "Loesche alte Regeln"
        $IPTABLES -F
        $IPTABLES -X
        $IPTABLES -P INPUT ACCEPT
        $IPTABLES -P FORWARD ACCEPT
        $IPTABLES -P OUTPUT ACCEPT
;;
*)
        echo "Usage: `basename $0` {start}" >&2
        exit